Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

26 files changed, 6548 insertions, 0 deletions

diff --git a/src/zstd/tests/fuzz/.gitignore b/src/zstd/tests/fuzz/.gitignore
new file mode 100644
index 000000000..b6fc6e506
--- /dev/null
+++ b/src/zstd/tests/fuzz/.gitignore
@@ -0,0 +1,20 @@
+# test artefacts
+corpora
+block_decompress
+block_round_trip
+dictionary_decompress
+dictionary_loader
+dictionary_round_trip
+dictionary_stream_round_trip
+raw_dictionary_round_trip
+simple_compress
+simple_decompress
+simple_round_trip
+stream_decompress
+stream_round_trip
+zstd_frame_info
+fuzz-*.log
+
+# misc
+trace
+tmp*
diff --git a/src/zstd/tests/fuzz/Makefile b/src/zstd/tests/fuzz/Makefile
new file mode 100644
index 000000000..1af3dc734
--- /dev/null
+++ b/src/zstd/tests/fuzz/Makefile
@@ -0,0 +1,212 @@
+# ################################################################
+# Copyright (c) 2016-2020, Facebook, Inc.
+# All rights reserved.
+#
+# This source code is licensed under both the BSD-style license (found in the
+# LICENSE file in the root directory of this source tree) and the GPLv2 (found
+# in the COPYING file in the root directory of this source tree).
+# You may select, at your option, one of the above-listed licenses.
+# ################################################################
+
+# Optionally user defined flags
+CFLAGS ?= -O3
+CXXFLAGS ?= -O3
+CPPFLAGS ?=
+LDFLAGS ?=
+ARFLAGS ?=
+LIB_FUZZING_ENGINE ?= libregression.a
+PYTHON ?= python
+ifeq ($(shell uname), Darwin)
+	DOWNLOAD?=curl -L -o
+else
+	DOWNLOAD?=wget -O
+endif
+CORPORA_URL_PREFIX:=https://github.com/facebook/zstd/releases/download/fuzz-corpora/
+
+ZSTDDIR = ../../lib
+PRGDIR = ../../programs
+
+FUZZ_CPPFLAGS := -I$(ZSTDDIR) -I$(ZSTDDIR)/common -I$(ZSTDDIR)/compress \
+	-I$(ZSTDDIR)/dictBuilder -I$(ZSTDDIR)/deprecated -I$(ZSTDDIR)/legacy \
+	-I$(PRGDIR) -DZSTD_MULTITHREAD -DZSTD_LEGACY_SUPPORT=1 $(CPPFLAGS)
+FUZZ_EXTRA_FLAGS := -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \
+	-Wstrict-aliasing=1 -Wswitch-enum -Wdeclaration-after-statement \
+	-Wstrict-prototypes -Wundef \
+	-Wvla -Wformat=2 -Winit-self -Wfloat-equal -Wwrite-strings \
+	-Wredundant-decls \
+	-g -fno-omit-frame-pointer
+FUZZ_CFLAGS := $(FUZZ_EXTRA_FLAGS) $(CFLAGS)
+FUZZ_CXXFLAGS := $(FUZZ_EXTRA_FLAGS) -std=c++11 $(CXXFLAGS)
+FUZZ_LDFLAGS := -pthread $(LDFLAGS)
+FUZZ_ARFLAGS := $(ARFLAGS)
+FUZZ_TARGET_FLAGS = $(FUZZ_CPPFLAGS) $(FUZZ_CXXFLAGS) $(FUZZ_LDFLAGS)
+
+FUZZ_ROUND_TRIP_FLAGS := -DFUZZING_ASSERT_VALID_SEQUENCE
+
+FUZZ_HEADERS := fuzz_helpers.h fuzz.h zstd_helpers.h fuzz_data_producer.h
+FUZZ_SRC := $(PRGDIR)/util.c ./fuzz_helpers.c ./zstd_helpers.c ./fuzz_data_producer.c
+
+ZSTDCOMMON_SRC := $(ZSTDDIR)/common/*.c
+ZSTDCOMP_SRC   := $(ZSTDDIR)/compress/*.c
+ZSTDDECOMP_SRC := $(ZSTDDIR)/decompress/*.c
+ZSTDDICT_SRC := $(ZSTDDIR)/dictBuilder/*.c
+ZSTDLEGACY_SRC := $(ZSTDDIR)/legacy/*.c
+FUZZ_SRC       := \
+	$(FUZZ_SRC) \
+	$(ZSTDDECOMP_SRC) \
+	$(ZSTDCOMMON_SRC) \
+	$(ZSTDCOMP_SRC) \
+	$(ZSTDDICT_SRC) \
+	$(ZSTDLEGACY_SRC)
+FUZZ_SRC := $(wildcard $(FUZZ_SRC))
+
+FUZZ_D_OBJ1 := $(subst $(ZSTDDIR)/common/,d_lib_common_,$(FUZZ_SRC))
+FUZZ_D_OBJ2 := $(subst $(ZSTDDIR)/compress/,d_lib_compress_,$(FUZZ_D_OBJ1))
+FUZZ_D_OBJ3 := $(subst $(ZSTDDIR)/decompress/,d_lib_decompress_,$(FUZZ_D_OBJ2))
+FUZZ_D_OBJ4 := $(subst $(ZSTDDIR)/dictBuilder/,d_lib_dictBuilder_,$(FUZZ_D_OBJ3))
+FUZZ_D_OBJ5 := $(subst $(ZSTDDIR)/legacy/,d_lib_legacy_,$(FUZZ_D_OBJ4))
+FUZZ_D_OBJ6 := $(subst $(PRGDIR)/,d_prg_,$(FUZZ_D_OBJ5))
+FUZZ_D_OBJ7 := $(subst $\./,d_fuzz_,$(FUZZ_D_OBJ6))
+FUZZ_DECOMPRESS_OBJ := $(FUZZ_D_OBJ7:.c=.o)
+
+FUZZ_RT_OBJ1 := $(subst $(ZSTDDIR)/common/,rt_lib_common_,$(FUZZ_SRC))
+FUZZ_RT_OBJ2 := $(subst $(ZSTDDIR)/compress/,rt_lib_compress_,$(FUZZ_RT_OBJ1))
+FUZZ_RT_OBJ3 := $(subst $(ZSTDDIR)/decompress/,rt_lib_decompress_,$(FUZZ_RT_OBJ2))
+FUZZ_RT_OBJ4 := $(subst $(ZSTDDIR)/dictBuilder/,rt_lib_dictBuilder_,$(FUZZ_RT_OBJ3))
+FUZZ_RT_OBJ5 := $(subst $(ZSTDDIR)/legacy/,rt_lib_legacy_,$(FUZZ_RT_OBJ4))
+FUZZ_RT_OBJ6 := $(subst $(PRGDIR)/,rt_prg_,$(FUZZ_RT_OBJ5))
+FUZZ_RT_OBJ7 := $(subst $\./,rt_fuzz_,$(FUZZ_RT_OBJ6))
+FUZZ_ROUND_TRIP_OBJ := $(FUZZ_RT_OBJ7:.c=.o)
+
+.PHONY: default all clean cleanall
+
+default: all
+
+FUZZ_TARGETS :=       \
+	simple_round_trip \
+	stream_round_trip \
+	block_round_trip  \
+	simple_decompress \
+	stream_decompress \
+	block_decompress  \
+	dictionary_round_trip \
+	dictionary_decompress \
+	zstd_frame_info \
+	simple_compress \
+	dictionary_loader \
+	raw_dictionary_round_trip \
+	dictionary_stream_round_trip
+
+all: $(FUZZ_TARGETS)
+
+rt_lib_common_%.o: $(ZSTDDIR)/common/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $(FUZZ_ROUND_TRIP_FLAGS) $< -c -o $@
+
+rt_lib_compress_%.o: $(ZSTDDIR)/compress/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $(FUZZ_ROUND_TRIP_FLAGS) $< -c -o $@
+
+rt_lib_decompress_%.o: $(ZSTDDIR)/decompress/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $(FUZZ_ROUND_TRIP_FLAGS) $< -c -o $@
+
+rt_lib_dictBuilder_%.o: $(ZSTDDIR)/dictBuilder/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $(FUZZ_ROUND_TRIP_FLAGS) $< -c -o $@
+
+rt_lib_legacy_%.o: $(ZSTDDIR)/legacy/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $(FUZZ_ROUND_TRIP_FLAGS) $< -c -o $@
+
+rt_prg_%.o: $(PRGDIR)/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $(FUZZ_ROUND_TRIP_FLAGS) $< -c -o $@
+
+rt_fuzz_%.o: %.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $(FUZZ_ROUND_TRIP_FLAGS) $< -c -o $@
+
+d_lib_common_%.o: $(ZSTDDIR)/common/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $< -c -o $@
+
+d_lib_compress_%.o: $(ZSTDDIR)/compress/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $< -c -o $@
+
+d_lib_decompress_%.o: $(ZSTDDIR)/decompress/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $< -c -o $@
+
+d_lib_dictBuilder_%.o: $(ZSTDDIR)/dictBuilder/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $< -c -o $@
+
+d_lib_legacy_%.o: $(ZSTDDIR)/legacy/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $< -c -o $@
+
+d_prg_%.o: $(PRGDIR)/%.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $< -c -o $@
+
+d_fuzz_%.o: %.c
+	$(CC) $(FUZZ_CPPFLAGS) $(FUZZ_CFLAGS) $< -c -o $@
+
+simple_round_trip: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_simple_round_trip.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_simple_round_trip.o $(LIB_FUZZING_ENGINE) -o $@
+
+stream_round_trip: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_stream_round_trip.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_stream_round_trip.o $(LIB_FUZZING_ENGINE) -o $@
+
+block_round_trip: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_block_round_trip.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_block_round_trip.o $(LIB_FUZZING_ENGINE) -o $@
+
+simple_decompress: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_simple_decompress.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_simple_decompress.o $(LIB_FUZZING_ENGINE) -o $@
+
+stream_decompress: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_stream_decompress.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_stream_decompress.o $(LIB_FUZZING_ENGINE) -o $@
+
+block_decompress: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_block_decompress.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_block_decompress.o $(LIB_FUZZING_ENGINE) -o $@
+
+dictionary_round_trip: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_dictionary_round_trip.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_dictionary_round_trip.o $(LIB_FUZZING_ENGINE) -o $@
+
+raw_dictionary_round_trip: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_raw_dictionary_round_trip.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_raw_dictionary_round_trip.o $(LIB_FUZZING_ENGINE) -o $@
+
+dictionary_stream_round_trip: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_dictionary_stream_round_trip.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_dictionary_stream_round_trip.o $(LIB_FUZZING_ENGINE) -o $@
+
+dictionary_decompress: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_dictionary_decompress.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_dictionary_decompress.o $(LIB_FUZZING_ENGINE) -o $@
+
+simple_compress: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_simple_compress.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_simple_compress.o $(LIB_FUZZING_ENGINE) -o $@
+
+zstd_frame_info: $(FUZZ_HEADERS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_zstd_frame_info.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_DECOMPRESS_OBJ) d_fuzz_zstd_frame_info.o $(LIB_FUZZING_ENGINE) -o $@
+
+dictionary_loader: $(FUZZ_HEADERS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_dictionary_loader.o
+	$(CXX) $(FUZZ_TARGET_FLAGS) $(FUZZ_ROUND_TRIP_OBJ) rt_fuzz_dictionary_loader.o $(LIB_FUZZING_ENGINE) -o $@
+
+libregression.a: $(FUZZ_HEADERS) $(PRGDIR)/util.h $(PRGDIR)/util.c d_fuzz_regression_driver.o
+	$(AR) $(FUZZ_ARFLAGS) $@ d_fuzz_regression_driver.o
+
+corpora/%_seed_corpus.zip:
+	@mkdir -p corpora
+	$(DOWNLOAD) $@ $(CORPORA_URL_PREFIX)$*_seed_corpus.zip
+
+corpora/%: corpora/%_seed_corpus.zip
+	unzip -q $^ -d $@
+
+.PHONY: corpora
+corpora: $(patsubst %,corpora/%,$(FUZZ_TARGETS))
+
+.PHONY: seedcorpora
+seedcorpora: $(patsubst %,corpora/%_seed_corpus.zip,$(FUZZ_TARGETS))
+
+regressiontest: corpora
+	CC="$(CC)" CXX="$(CXX)" CFLAGS="$(CFLAGS)" CXXFLAGS="$(CXXFLAGS)" LDFLAGS="$(LDFLAGS)" $(PYTHON) ./fuzz.py build all
+	$(PYTHON) ./fuzz.py regression all
+
+clean:
+	@$(RM) *.a *.o
+	@$(RM) simple_round_trip stream_round_trip simple_decompress \
+           stream_decompress block_decompress block_round_trip \
+           simple_compress dictionary_round_trip dictionary_decompress \
+           zstd_frame_info
+
+cleanall:
+	@$(RM) -r Fuzzer
+	@$(RM) -r corpora
diff --git a/src/zstd/tests/fuzz/README.md b/src/zstd/tests/fuzz/README.md
new file mode 100644
index 000000000..71afa4063
--- /dev/null
+++ b/src/zstd/tests/fuzz/README.md
@@ -0,0 +1,101 @@
+# Fuzzing
+
+Each fuzzing target can be built with multiple engines.
+Zstd provides a fuzz corpus for each target that can be downloaded with
+the command:
+
+```
+make corpora
+```
+
+It will download each corpus into `./corpora/TARGET`.
+
+## fuzz.py
+
+`fuzz.py` is a helper script for building and running fuzzers.
+Run `./fuzz.py -h` for the commands and run `./fuzz.py COMMAND -h` for
+command specific help.
+
+### Generating Data
+
+`fuzz.py` provides a utility to generate seed data for each fuzzer.
+
+```
+make -C ../tests decodecorpus
+./fuzz.py gen TARGET
+```
+
+By default it outputs 100 samples, each at most 8KB into `corpora/TARGET-seed`,
+but that can be configured with the `--number`, `--max-size-log` and `--seed`
+flags.
+
+### Build
+It respects the usual build environment variables `CC`, `CFLAGS`, etc.
+The environment variables can be overridden with the corresponding flags
+`--cc`, `--cflags`, etc.
+The specific fuzzing engine is selected with `LIB_FUZZING_ENGINE` or
+`--lib-fuzzing-engine`, the default is `libregression.a`.
+Alternatively, you can use Clang's built in fuzzing engine with
+`--enable-fuzzer`.
+It has flags that can easily set up sanitizers `--enable-{a,ub,m}san`, and
+coverage instrumentation `--enable-coverage`.
+It sets sane defaults which can be overridden with flags `--debug`,
+`--enable-ubsan-pointer-overflow`, etc.
+Run `./fuzz.py build -h` for help.
+
+### Running Fuzzers
+
+`./fuzz.py` can run `libfuzzer`, `afl`, and `regression` tests.
+See the help of the relevant command for options.
+Flags not parsed by `fuzz.py` are passed to the fuzzing engine.
+The command used to run the fuzzer is printed for debugging.
+
+## LibFuzzer
+
+```
+# Build the fuzz targets
+./fuzz.py build all --enable-fuzzer --enable-asan --enable-ubsan --cc clang --cxx clang++
+# OR equivalently
+CC=clang CXX=clang++ ./fuzz.py build all --enable-fuzzer --enable-asan --enable-ubsan
+# Run the fuzzer
+./fuzz.py libfuzzer TARGET <libfuzzer args like -jobs=4>
+```
+
+where `TARGET` could be `simple_decompress`, `stream_round_trip`, etc.
+
+### MSAN
+
+Fuzzing with `libFuzzer` and `MSAN` is as easy as:
+
+```
+CC=clang CXX=clang++ ./fuzz.py build all --enable-fuzzer --enable-msan
+./fuzz.py libfuzzer TARGET <libfuzzer args>
+```
+
+`fuzz.py` respects the environment variables / flags `MSAN_EXTRA_CPPFLAGS`,
+`MSAN_EXTRA_CFLAGS`, `MSAN_EXTRA_CXXFLAGS`, `MSAN_EXTRA_LDFLAGS` to easily pass
+the extra parameters only for MSAN.
+
+## AFL
+
+The default `LIB_FUZZING_ENGINE` is `libregression.a`, which produces a binary
+that AFL can use.
+
+```
+# Build the fuzz targets
+CC=afl-clang CXX=afl-clang++ ./fuzz.py build all --enable-asan --enable-ubsan
+# Run the fuzzer without a memory limit because of ASAN
+./fuzz.py afl TARGET -m none
+```
+
+## Regression Testing
+
+The regression test supports the `all` target to run all the fuzzers in one
+command.
+
+```
+CC=clang CXX=clang++ ./fuzz.py build all --enable-asan --enable-ubsan
+./fuzz.py regression all
+CC=clang CXX=clang++ ./fuzz.py build all --enable-msan
+./fuzz.py regression all
+```
diff --git a/src/zstd/tests/fuzz/block_decompress.c b/src/zstd/tests/fuzz/block_decompress.c
new file mode 100644
index 000000000..64d70f005
--- /dev/null
+++ b/src/zstd/tests/fuzz/block_decompress.c
@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the simple
+ * decompression function to ensure the decompressor never crashes.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+
+static ZSTD_DCtx *dctx = NULL;
+static void* rBuf = NULL;
+static size_t bufSize = 0;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    size_t const neededBufSize = ZSTD_BLOCKSIZE_MAX;
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize) {
+        free(rBuf);
+        rBuf = FUZZ_malloc(neededBufSize);
+        bufSize = neededBufSize;
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+    ZSTD_decompressBegin(dctx);
+    ZSTD_decompressBlock(dctx, rBuf, neededBufSize, src, size);
+
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/block_round_trip.c b/src/zstd/tests/fuzz/block_round_trip.c
new file mode 100644
index 000000000..097fc01b8
--- /dev/null
+++ b/src/zstd/tests/fuzz/block_round_trip.c
@@ -0,0 +1,99 @@
+/**
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+static void* cBuf = NULL;
+static void* rBuf = NULL;
+static size_t bufSize = 0;
+
+static size_t roundTripTest(void *result, size_t resultCapacity,
+                            void *compressed, size_t compressedCapacity,
+                            const void *src, size_t srcSize,
+                            int cLevel)
+{
+    ZSTD_parameters const params = ZSTD_getParams(cLevel, srcSize, 0);
+    size_t ret = ZSTD_compressBegin_advanced(cctx, NULL, 0, params, srcSize);
+    FUZZ_ZASSERT(ret);
+
+    ret = ZSTD_compressBlock(cctx, compressed, compressedCapacity, src, srcSize);
+    FUZZ_ZASSERT(ret);
+    if (ret == 0) {
+        FUZZ_ASSERT(resultCapacity >= srcSize);
+        if (srcSize > 0) {
+            memcpy(result, src, srcSize);
+        }
+        return srcSize;
+    }
+    ZSTD_decompressBegin(dctx);
+    return ZSTD_decompressBlock(dctx, result, resultCapacity, compressed, ret);
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);
+
+    size_t neededBufSize = size;
+    if (size > ZSTD_BLOCKSIZE_MAX)
+        size = ZSTD_BLOCKSIZE_MAX;
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize || !cBuf || !rBuf) {
+        free(cBuf);
+        free(rBuf);
+        cBuf = FUZZ_malloc(neededBufSize);
+        rBuf = FUZZ_malloc(neededBufSize);
+        bufSize = neededBufSize;
+    }
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const result =
+            roundTripTest(rBuf, neededBufSize, cBuf, neededBufSize, src, size,
+              cLevel);
+        FUZZ_ZASSERT(result);
+        FUZZ_ASSERT_MSG(result == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+    }
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/dictionary_decompress.c b/src/zstd/tests/fuzz/dictionary_decompress.c
new file mode 100644
index 000000000..9944baa15
--- /dev/null
+++ b/src/zstd/tests/fuzz/dictionary_decompress.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the dictionary
+ * decompression function to ensure the decompressor never crashes. It does not
+ * fuzz the dictionary.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_DCtx *dctx = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    FUZZ_dict_t dict;
+    ZSTD_DDict* ddict = NULL;
+
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+    dict = FUZZ_train(src, size, producer);
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0) {
+        ddict = ZSTD_createDDict(dict.buff, dict.size);
+        FUZZ_ASSERT(ddict);
+    } else {
+        if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0)
+            FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+                dctx, dict.buff, dict.size,
+                (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+                (ZSTD_dictContentType_e)FUZZ_dataProducer_uint32Range(producer, 0, 2)));
+        else
+            FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+                dctx, dict.buff, dict.size,
+                (ZSTD_dictContentType_e)FUZZ_dataProducer_uint32Range(producer, 0, 2)));
+    }
+
+    {
+        size_t const bufSize = FUZZ_dataProducer_uint32Range(producer, 0, 10 * size);
+        void* rBuf = FUZZ_malloc(bufSize);
+        if (ddict) {
+            ZSTD_decompress_usingDDict(dctx, rBuf, bufSize, src, size, ddict);
+        } else {
+            ZSTD_decompressDCtx(dctx, rBuf, bufSize, src, size);
+        }
+        free(rBuf);
+    }
+    free(dict.buff);
+    FUZZ_dataProducer_free(producer);
+    ZSTD_freeDDict(ddict);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/dictionary_loader.c b/src/zstd/tests/fuzz/dictionary_loader.c
new file mode 100644
index 000000000..f1fdf4da9
--- /dev/null
+++ b/src/zstd/tests/fuzz/dictionary_loader.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target makes sure that whenever a compression dictionary can be
+ * loaded, the data can be round tripped.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+/**
+ * Compresses the data and returns the compressed size or an error.
+ */
+static size_t compress(void* compressed, size_t compressedCapacity,
+                       void const* source, size_t sourceSize,
+                       void const* dict, size_t dictSize,
+                       ZSTD_dictLoadMethod_e dictLoadMethod,
+                       ZSTD_dictContentType_e dictContentType,
+                       int const refPrefix)
+{
+    ZSTD_CCtx* cctx = ZSTD_createCCtx();
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+            cctx, dict, dictSize, dictContentType));
+    else 
+        FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
+            cctx, dict, dictSize, dictLoadMethod, dictContentType));
+    size_t const compressedSize = ZSTD_compress2(
+            cctx, compressed, compressedCapacity, source, sourceSize);
+    ZSTD_freeCCtx(cctx);
+    return compressedSize;
+}
+
+static size_t decompress(void* result, size_t resultCapacity,
+                         void const* compressed, size_t compressedSize,
+                         void const* dict, size_t dictSize,
+                       ZSTD_dictLoadMethod_e dictLoadMethod,
+                         ZSTD_dictContentType_e dictContentType,
+                         int const refPrefix)
+{
+    ZSTD_DCtx* dctx = ZSTD_createDCtx();
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+            dctx, dict, dictSize, dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+            dctx, dict, dictSize, dictLoadMethod, dictContentType));
+    size_t const resultSize = ZSTD_decompressDCtx(
+            dctx, result, resultCapacity, compressed, compressedSize);
+    FUZZ_ZASSERT(resultSize);
+    ZSTD_freeDCtx(dctx);
+    return resultSize;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
+    ZSTD_dictLoadMethod_e const dlm =
+    size = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    ZSTD_dictContentType_e const dct =
+            FUZZ_dataProducer_uint32Range(producer, 0, 2);
+    size = FUZZ_dataProducer_remainingBytes(producer);
+
+    DEBUGLOG(2, "Dict load method %d", dlm);
+    DEBUGLOG(2, "Dict content type %d", dct);
+    DEBUGLOG(2, "Dict size %u", (unsigned)size);
+
+    void* const rBuf = FUZZ_malloc(size);
+    size_t const cBufSize = ZSTD_compressBound(size);
+    void* const cBuf = FUZZ_malloc(cBufSize);
+
+    size_t const cSize =
+            compress(cBuf, cBufSize, src, size, src, size, dlm, dct, refPrefix);
+    /* compression failing is okay */
+    if (ZSTD_isError(cSize)) {
+      FUZZ_ASSERT_MSG(dct != ZSTD_dct_rawContent, "Raw must always succeed!");
+      goto out;
+    }
+    size_t const rSize =
+            decompress(rBuf, size, cBuf, cSize, src, size, dlm, dct, refPrefix);
+    FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
+    FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+
+out:
+    free(cBuf);
+    free(rBuf);
+    FUZZ_dataProducer_free(producer);
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/dictionary_round_trip.c b/src/zstd/tests/fuzz/dictionary_round_trip.c
new file mode 100644
index 000000000..7b7771e48
--- /dev/null
+++ b/src/zstd/tests/fuzz/dictionary_round_trip.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress) with
+ * a dictionary, compares the result with the original, and calls abort() on
+ * corruption.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+
+static size_t roundTripTest(void *result, size_t resultCapacity,
+                            void *compressed, size_t compressedCapacity,
+                            const void *src, size_t srcSize,
+                            FUZZ_dataProducer_t *producer)
+{
+    ZSTD_dictContentType_e dictContentType = ZSTD_dct_auto;
+    FUZZ_dict_t dict = FUZZ_train(src, srcSize, producer);
+    int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
+    size_t cSize;
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 15) == 0) {
+        int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);
+
+        cSize = ZSTD_compress_usingDict(cctx,
+                compressed, compressedCapacity,
+                src, srcSize,
+                dict.buff, dict.size,
+                cLevel);
+    } else {
+        dictContentType = FUZZ_dataProducer_uint32Range(producer, 0, 2);
+        FUZZ_setRandomParameters(cctx, srcSize, producer);
+        /* Disable checksum so we can use sizes smaller than compress bound. */
+        FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 0));
+        if (refPrefix)
+            FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+                cctx, dict.buff, dict.size,
+                dictContentType));
+        else 
+            FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
+                cctx, dict.buff, dict.size,
+                (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+                dictContentType));
+        cSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+    }
+    FUZZ_ZASSERT(cSize);
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+            dctx, dict.buff, dict.size,
+            dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+            dctx, dict.buff, dict.size,
+            (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+            dictContentType));
+    {
+        size_t const ret = ZSTD_decompressDCtx(
+                dctx, result, resultCapacity, compressed, cSize);
+        free(dict.buff);
+        return ret;
+    }
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    size_t const rBufSize = size;
+    void* rBuf = FUZZ_malloc(rBufSize);
+    size_t cBufSize = ZSTD_compressBound(size);
+    void *cBuf;
+    /* Half of the time fuzz with a 1 byte smaller output size.
+     * This will still succeed because we force the checksum to be disabled,
+     * giving us 4 bytes of overhead.
+     */
+    cBufSize -= FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    cBuf = FUZZ_malloc(cBufSize);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const result =
+            roundTripTest(rBuf, rBufSize, cBuf, cBufSize, src, size, producer);
+        FUZZ_ZASSERT(result);
+        FUZZ_ASSERT_MSG(result == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+    }
+    free(rBuf);
+    free(cBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/dictionary_stream_round_trip.c b/src/zstd/tests/fuzz/dictionary_stream_round_trip.c
new file mode 100644
index 000000000..67e8c69ef
--- /dev/null
+++ b/src/zstd/tests/fuzz/dictionary_stream_round_trip.c
@@ -0,0 +1,206 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+static uint8_t* cBuf = NULL;
+static uint8_t* rBuf = NULL;
+static size_t bufSize = 0;
+
+static ZSTD_outBuffer makeOutBuffer(uint8_t *dst, size_t capacity,
+                                    FUZZ_dataProducer_t *producer)
+{
+    ZSTD_outBuffer buffer = { dst, 0, 0 };
+
+    FUZZ_ASSERT(capacity > 0);
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, capacity));
+    FUZZ_ASSERT(buffer.size <= capacity);
+
+    return buffer;
+}
+
+static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size,
+                                  FUZZ_dataProducer_t *producer)
+{
+    ZSTD_inBuffer buffer = { *src, 0, 0 };
+
+    FUZZ_ASSERT(*size > 0);
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, *size));
+    FUZZ_ASSERT(buffer.size <= *size);
+    *src += buffer.size;
+    *size -= buffer.size;
+
+    return buffer;
+}
+
+static size_t compress(uint8_t *dst, size_t capacity,
+                        const uint8_t *src, size_t srcSize,
+                        const uint8_t* dict, size_t dictSize,
+                        FUZZ_dataProducer_t *producer, int refPrefix,
+                        ZSTD_dictContentType_e dictContentType)
+{
+    size_t dstSize = 0;
+    ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+    FUZZ_setRandomParameters(cctx, srcSize, producer);
+
+    /* Disable checksum so we can use sizes smaller than compress bound. */
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 0));
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+            cctx, dict, dictSize,
+            dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
+            cctx, dict, dictSize,
+            (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+            dictContentType));
+
+    while (srcSize > 0) {
+        ZSTD_inBuffer in = makeInBuffer(&src, &srcSize, producer);
+        /* Mode controls the action. If mode == -1 we pick a new mode */
+        int mode = -1;
+        while (in.pos < in.size || mode != -1) {
+            ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
+            /* Previous action finished, pick a new mode. */
+            if (mode == -1) mode = FUZZ_dataProducer_uint32Range(producer, 0, 9);
+            switch (mode) {
+                case 0: /* fall-through */
+                case 1: /* fall-through */
+                case 2: {
+                    size_t const ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush);
+                    FUZZ_ZASSERT(ret);
+                    if (ret == 0)
+                        mode = -1;
+                    break;
+                }
+                case 3: {
+                    size_t ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+                    FUZZ_ZASSERT(ret);
+                    /* Reset the compressor when the frame is finished */
+                    if (ret == 0) {
+                        ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+                        if (FUZZ_dataProducer_uint32Range(producer, 0, 7) == 0) {
+                            size_t const remaining = in.size - in.pos;
+                            FUZZ_setRandomParameters(cctx, remaining, producer);
+                        }
+                        mode = -1;
+                    }
+                    break;
+                }
+                case 4: {
+                    ZSTD_inBuffer nullIn = { NULL, 0, 0 };
+                    ZSTD_outBuffer nullOut = { NULL, 0, 0 };
+                    size_t const ret = ZSTD_compressStream2(cctx, &nullOut, &nullIn, ZSTD_e_continue);
+                    FUZZ_ZASSERT(ret);
+                }
+                /* fall-through */
+                default: {
+                    size_t const ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_continue);
+                    FUZZ_ZASSERT(ret);
+                    mode = -1;
+                }
+            }
+            dst += out.pos;
+            dstSize += out.pos;
+            capacity -= out.pos;
+        }
+    }
+    for (;;) {
+        ZSTD_inBuffer in = {NULL, 0, 0};
+        ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
+        size_t const ret = ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+        FUZZ_ZASSERT(ret);
+
+        dst += out.pos;
+        dstSize += out.pos;
+        capacity -= out.pos;
+        if (ret == 0)
+            break;
+    }
+    return dstSize;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    size_t neededBufSize;
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    neededBufSize = ZSTD_compressBound(size) * 15;
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize) {
+        free(cBuf);
+        free(rBuf);
+        cBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
+        rBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
+        bufSize = neededBufSize;
+    }
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        ZSTD_dictContentType_e dictContentType = FUZZ_dataProducer_uint32Range(producer, 0, 2);
+        FUZZ_dict_t dict = FUZZ_train(src, size, producer);
+        int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
+
+        size_t const cSize = compress(cBuf, neededBufSize, src, size, dict.buff, dict.size, producer, refPrefix, dictContentType);
+
+        if (refPrefix)
+            FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+                dctx, dict.buff, dict.size,
+                dictContentType));
+        else
+            FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+                dctx, dict.buff, dict.size,
+                (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+                dictContentType));
+        size_t const rSize =
+            ZSTD_decompressDCtx(dctx, rBuf, neededBufSize, cBuf, cSize);
+        FUZZ_ZASSERT(rSize);
+        FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+        free(dict.buff);
+    }
+
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/fuzz.h b/src/zstd/tests/fuzz/fuzz.h
new file mode 100644
index 000000000..8ee964536
--- /dev/null
+++ b/src/zstd/tests/fuzz/fuzz.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * Fuzz target interface.
+ * Fuzz targets have some common parameters passed as macros during compilation.
+ * Check the documentation for each individual fuzzer for more parameters.
+ *
+ * @param STATEFUL_FUZZING:
+ *        Define this to reuse state between fuzzer runs. This can be useful to
+ *        test code paths which are only executed when contexts are reused.
+ *        WARNING: Makes reproducing crashes much harder.
+ *        Default: Not defined.
+ * @param DEBUGLEVEL:
+ *        This is a parameter for the zstd library. Defining `DEBUGLEVEL=1`
+ *        enables assert() statements in the zstd library. Higher levels enable
+ *        logging, so aren't recommended. Defining `DEBUGLEVEL=1` is
+ *        recommended.
+ * @param MEM_FORCE_MEMORY_ACCESS:
+ *        This flag controls how the zstd library accesses unaligned memory.
+ *        It can be undefined, or 0 through 2. If it is undefined, it selects
+ *        the method to use based on the compiler. If testing with UBSAN set
+ *        MEM_FORCE_MEMORY_ACCESS=0 to use the standard compliant method.
+ * @param FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+ *        This is the canonical flag to enable deterministic builds for fuzzing.
+ *        Changes to zstd for fuzzing are gated behind this define.
+ *        It is recommended to define this when building zstd for fuzzing.
+ */
+
+#ifndef FUZZ_H
+#define FUZZ_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/zstd/tests/fuzz/fuzz.py b/src/zstd/tests/fuzz/fuzz.py
new file mode 100755
index 000000000..6875d1d60
--- /dev/null
+++ b/src/zstd/tests/fuzz/fuzz.py
@@ -0,0 +1,887 @@
+#!/usr/bin/env python
+
+# ################################################################
+# Copyright (c) 2016-2020, Facebook, Inc.
+# All rights reserved.
+#
+# This source code is licensed under both the BSD-style license (found in the
+# LICENSE file in the root directory of this source tree) and the GPLv2 (found
+# in the COPYING file in the root directory of this source tree).
+# You may select, at your option, one of the above-listed licenses.
+# ##########################################################################
+
+import argparse
+import contextlib
+import os
+import re
+import shlex
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+def abs_join(a, *p):
+    return os.path.abspath(os.path.join(a, *p))
+
+
+class InputType(object):
+    RAW_DATA = 1
+    COMPRESSED_DATA = 2
+    DICTIONARY_DATA = 3
+
+
+class FrameType(object):
+    ZSTD = 1
+    BLOCK = 2
+
+
+class TargetInfo(object):
+    def __init__(self, input_type, frame_type=FrameType.ZSTD):
+        self.input_type = input_type
+        self.frame_type = frame_type
+
+
+# Constants
+FUZZ_DIR = os.path.abspath(os.path.dirname(__file__))
+CORPORA_DIR = abs_join(FUZZ_DIR, 'corpora')
+TARGET_INFO = {
+    'simple_round_trip': TargetInfo(InputType.RAW_DATA),
+    'stream_round_trip': TargetInfo(InputType.RAW_DATA),
+    'block_round_trip': TargetInfo(InputType.RAW_DATA, FrameType.BLOCK),
+    'simple_decompress': TargetInfo(InputType.COMPRESSED_DATA),
+    'stream_decompress': TargetInfo(InputType.COMPRESSED_DATA),
+    'block_decompress': TargetInfo(InputType.COMPRESSED_DATA, FrameType.BLOCK),
+    'dictionary_round_trip': TargetInfo(InputType.RAW_DATA),
+    'dictionary_decompress': TargetInfo(InputType.COMPRESSED_DATA),
+    'zstd_frame_info': TargetInfo(InputType.COMPRESSED_DATA),
+    'simple_compress': TargetInfo(InputType.RAW_DATA),
+    'dictionary_loader': TargetInfo(InputType.DICTIONARY_DATA),
+    'raw_dictionary_round_trip': TargetInfo(InputType.RAW_DATA),
+    'dictionary_stream_round_trip': TargetInfo(InputType.RAW_DATA),
+}
+TARGETS = list(TARGET_INFO.keys())
+ALL_TARGETS = TARGETS + ['all']
+FUZZ_RNG_SEED_SIZE = 4
+
+# Standard environment variables
+CC = os.environ.get('CC', 'cc')
+CXX = os.environ.get('CXX', 'c++')
+CPPFLAGS = os.environ.get('CPPFLAGS', '')
+CFLAGS = os.environ.get('CFLAGS', '-O3')
+CXXFLAGS = os.environ.get('CXXFLAGS', CFLAGS)
+LDFLAGS = os.environ.get('LDFLAGS', '')
+MFLAGS = os.environ.get('MFLAGS', '-j')
+
+# Fuzzing environment variables
+LIB_FUZZING_ENGINE = os.environ.get('LIB_FUZZING_ENGINE', 'libregression.a')
+AFL_FUZZ = os.environ.get('AFL_FUZZ', 'afl-fuzz')
+DECODECORPUS = os.environ.get('DECODECORPUS',
+                              abs_join(FUZZ_DIR, '..', 'decodecorpus'))
+ZSTD = os.environ.get('ZSTD', abs_join(FUZZ_DIR, '..', '..', 'zstd'))
+
+# Sanitizer environment variables
+MSAN_EXTRA_CPPFLAGS = os.environ.get('MSAN_EXTRA_CPPFLAGS', '')
+MSAN_EXTRA_CFLAGS = os.environ.get('MSAN_EXTRA_CFLAGS', '')
+MSAN_EXTRA_CXXFLAGS = os.environ.get('MSAN_EXTRA_CXXFLAGS', '')
+MSAN_EXTRA_LDFLAGS = os.environ.get('MSAN_EXTRA_LDFLAGS', '')
+
+
+def create(r):
+    d = os.path.abspath(r)
+    if not os.path.isdir(d):
+        os.makedirs(d)
+    return d
+
+
+def check(r):
+    d = os.path.abspath(r)
+    if not os.path.isdir(d):
+        return None
+    return d
+
+
+@contextlib.contextmanager
+def tmpdir():
+    dirpath = tempfile.mkdtemp()
+    try:
+        yield dirpath
+    finally:
+        shutil.rmtree(dirpath, ignore_errors=True)
+
+
+def parse_targets(in_targets):
+    targets = set()
+    for target in in_targets:
+        if not target:
+            continue
+        if target == 'all':
+            targets = targets.union(TARGETS)
+        elif target in TARGETS:
+            targets.add(target)
+        else:
+            raise RuntimeError('{} is not a valid target'.format(target))
+    return list(targets)
+
+
+def targets_parser(args, description):
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        'TARGET',
+        nargs='*',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(ALL_TARGETS)))
+    args, extra = parser.parse_known_args(args)
+    args.extra = extra
+
+    args.TARGET = parse_targets(args.TARGET)
+
+    return args
+
+
+def parse_env_flags(args, flags):
+    """
+    Look for flags set by environment variables.
+    """
+    san_flags = ','.join(re.findall('-fsanitize=((?:[a-z]+,?)+)', flags))
+    nosan_flags = ','.join(re.findall('-fno-sanitize=((?:[a-z]+,?)+)', flags))
+
+    def set_sanitizer(sanitizer, default, san, nosan):
+        if sanitizer in san and sanitizer in nosan:
+            raise RuntimeError('-fno-sanitize={s} and -fsanitize={s} passed'.
+                               format(s=sanitizer))
+        if sanitizer in san:
+            return True
+        if sanitizer in nosan:
+            return False
+        return default
+
+    san = set(san_flags.split(','))
+    nosan = set(nosan_flags.split(','))
+
+    args.asan = set_sanitizer('address', args.asan, san, nosan)
+    args.msan = set_sanitizer('memory', args.msan, san, nosan)
+    args.ubsan = set_sanitizer('undefined', args.ubsan, san, nosan)
+
+    args.sanitize = args.asan or args.msan or args.ubsan
+
+    return args
+
+
+def compiler_version(cc, cxx):
+    """
+    Determines the compiler and version.
+    Only works for clang and gcc.
+    """
+    cc_version_bytes = subprocess.check_output([cc, "--version"])
+    cxx_version_bytes = subprocess.check_output([cxx, "--version"])
+    compiler = None
+    version = None
+    if b'clang' in cc_version_bytes:
+        assert(b'clang' in cxx_version_bytes)
+        compiler = 'clang'
+    elif b'gcc' in cc_version_bytes:
+        assert(b'gcc' in cxx_version_bytes or b'g++' in cxx_version_bytes)
+        compiler = 'gcc'
+    if compiler is not None:
+        version_regex = b'([0-9])+\.([0-9])+\.([0-9])+'
+        version_match = re.search(version_regex, cc_version_bytes)
+        version = tuple(int(version_match.group(i)) for i in range(1, 4))
+    return compiler, version
+
+
+def overflow_ubsan_flags(cc, cxx):
+    compiler, version = compiler_version(cc, cxx)
+    if compiler == 'gcc':
+        return ['-fno-sanitize=signed-integer-overflow']
+    if compiler == 'clang' and version >= (5, 0, 0):
+        return ['-fno-sanitize=pointer-overflow']
+    return []
+
+
+def build_parser(args):
+    description = """
+    Cleans the repository and builds a fuzz target (or all).
+    Many flags default to environment variables (default says $X='y').
+    Options that aren't enabling features default to the correct values for
+    zstd.
+    Enable sanitizers with --enable-*san.
+    For regression testing just build.
+    For libFuzzer set LIB_FUZZING_ENGINE and pass --enable-coverage.
+    For AFL set CC and CXX to AFL's compilers and set
+    LIB_FUZZING_ENGINE='libregression.a'.
+    """
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        '--lib-fuzzing-engine',
+        dest='lib_fuzzing_engine',
+        type=str,
+        default=LIB_FUZZING_ENGINE,
+        help=('The fuzzing engine to use e.g. /path/to/libFuzzer.a '
+              "(default: $LIB_FUZZING_ENGINE='{})".format(LIB_FUZZING_ENGINE)))
+
+    fuzz_group = parser.add_mutually_exclusive_group()
+    fuzz_group.add_argument(
+        '--enable-coverage',
+        dest='coverage',
+        action='store_true',
+        help='Enable coverage instrumentation (-fsanitize-coverage)')
+    fuzz_group.add_argument(
+        '--enable-fuzzer',
+        dest='fuzzer',
+        action='store_true',
+        help=('Enable clang fuzzer (-fsanitize=fuzzer). When enabled '
+              'LIB_FUZZING_ENGINE is ignored')
+    )
+
+    parser.add_argument(
+        '--enable-asan', dest='asan', action='store_true', help='Enable UBSAN')
+    parser.add_argument(
+        '--enable-ubsan',
+        dest='ubsan',
+        action='store_true',
+        help='Enable UBSAN')
+    parser.add_argument(
+        '--enable-ubsan-pointer-overflow',
+        dest='ubsan_pointer_overflow',
+        action='store_true',
+        help='Enable UBSAN pointer overflow check (known failure)')
+    parser.add_argument(
+        '--enable-msan', dest='msan', action='store_true', help='Enable MSAN')
+    parser.add_argument(
+        '--enable-msan-track-origins', dest='msan_track_origins',
+        action='store_true', help='Enable MSAN origin tracking')
+    parser.add_argument(
+        '--msan-extra-cppflags',
+        dest='msan_extra_cppflags',
+        type=str,
+        default=MSAN_EXTRA_CPPFLAGS,
+        help="Extra CPPFLAGS for MSAN (default: $MSAN_EXTRA_CPPFLAGS='{}')".
+        format(MSAN_EXTRA_CPPFLAGS))
+    parser.add_argument(
+        '--msan-extra-cflags',
+        dest='msan_extra_cflags',
+        type=str,
+        default=MSAN_EXTRA_CFLAGS,
+        help="Extra CFLAGS for MSAN (default: $MSAN_EXTRA_CFLAGS='{}')".format(
+            MSAN_EXTRA_CFLAGS))
+    parser.add_argument(
+        '--msan-extra-cxxflags',
+        dest='msan_extra_cxxflags',
+        type=str,
+        default=MSAN_EXTRA_CXXFLAGS,
+        help="Extra CXXFLAGS for MSAN (default: $MSAN_EXTRA_CXXFLAGS='{}')".
+        format(MSAN_EXTRA_CXXFLAGS))
+    parser.add_argument(
+        '--msan-extra-ldflags',
+        dest='msan_extra_ldflags',
+        type=str,
+        default=MSAN_EXTRA_LDFLAGS,
+        help="Extra LDFLAGS for MSAN (default: $MSAN_EXTRA_LDFLAGS='{}')".
+        format(MSAN_EXTRA_LDFLAGS))
+    parser.add_argument(
+        '--enable-sanitize-recover',
+        dest='sanitize_recover',
+        action='store_true',
+        help='Non-fatal sanitizer errors where possible')
+    parser.add_argument(
+        '--debug',
+        dest='debug',
+        type=int,
+        default=1,
+        help='Set DEBUGLEVEL (default: 1)')
+    parser.add_argument(
+        '--force-memory-access',
+        dest='memory_access',
+        type=int,
+        default=0,
+        help='Set MEM_FORCE_MEMORY_ACCESS (default: 0)')
+    parser.add_argument(
+        '--fuzz-rng-seed-size',
+        dest='fuzz_rng_seed_size',
+        type=int,
+        default=4,
+        help='Set FUZZ_RNG_SEED_SIZE (default: 4)')
+    parser.add_argument(
+        '--disable-fuzzing-mode',
+        dest='fuzzing_mode',
+        action='store_false',
+        help='Do not define FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION')
+    parser.add_argument(
+        '--enable-stateful-fuzzing',
+        dest='stateful_fuzzing',
+        action='store_true',
+        help='Reuse contexts between runs (makes reproduction impossible)')
+    parser.add_argument(
+        '--cc',
+        dest='cc',
+        type=str,
+        default=CC,
+        help="CC (default: $CC='{}')".format(CC))
+    parser.add_argument(
+        '--cxx',
+        dest='cxx',
+        type=str,
+        default=CXX,
+        help="CXX (default: $CXX='{}')".format(CXX))
+    parser.add_argument(
+        '--cppflags',
+        dest='cppflags',
+        type=str,
+        default=CPPFLAGS,
+        help="CPPFLAGS (default: $CPPFLAGS='{}')".format(CPPFLAGS))
+    parser.add_argument(
+        '--cflags',
+        dest='cflags',
+        type=str,
+        default=CFLAGS,
+        help="CFLAGS (default: $CFLAGS='{}')".format(CFLAGS))
+    parser.add_argument(
+        '--cxxflags',
+        dest='cxxflags',
+        type=str,
+        default=CXXFLAGS,
+        help="CXXFLAGS (default: $CXXFLAGS='{}')".format(CXXFLAGS))
+    parser.add_argument(
+        '--ldflags',
+        dest='ldflags',
+        type=str,
+        default=LDFLAGS,
+        help="LDFLAGS (default: $LDFLAGS='{}')".format(LDFLAGS))
+    parser.add_argument(
+        '--mflags',
+        dest='mflags',
+        type=str,
+        default=MFLAGS,
+        help="Extra Make flags (default: $MFLAGS='{}')".format(MFLAGS))
+    parser.add_argument(
+        'TARGET',
+        nargs='*',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(ALL_TARGETS))
+    )
+    args = parser.parse_args(args)
+    args = parse_env_flags(args, ' '.join(
+        [args.cppflags, args.cflags, args.cxxflags, args.ldflags]))
+
+    # Check option sanity
+    if args.msan and (args.asan or args.ubsan):
+        raise RuntimeError('MSAN may not be used with any other sanitizers')
+    if args.msan_track_origins and not args.msan:
+        raise RuntimeError('--enable-msan-track-origins requires MSAN')
+    if args.ubsan_pointer_overflow and not args.ubsan:
+        raise RuntimeError('--enable-ubsan-pointer-overflow requires UBSAN')
+    if args.sanitize_recover and not args.sanitize:
+        raise RuntimeError('--enable-sanitize-recover but no sanitizers used')
+
+    return args
+
+
+def build(args):
+    try:
+        args = build_parser(args)
+    except Exception as e:
+        print(e)
+        return 1
+    # The compilation flags we are setting
+    targets = args.TARGET
+    cc = args.cc
+    cxx = args.cxx
+    cppflags = shlex.split(args.cppflags)
+    cflags = shlex.split(args.cflags)
+    ldflags = shlex.split(args.ldflags)
+    cxxflags = shlex.split(args.cxxflags)
+    mflags = shlex.split(args.mflags)
+    # Flags to be added to both cflags and cxxflags
+    common_flags = []
+
+    cppflags += [
+        '-DDEBUGLEVEL={}'.format(args.debug),
+        '-DMEM_FORCE_MEMORY_ACCESS={}'.format(args.memory_access),
+        '-DFUZZ_RNG_SEED_SIZE={}'.format(args.fuzz_rng_seed_size),
+    ]
+
+    # Set flags for options
+    assert not (args.fuzzer and args.coverage)
+    if args.coverage:
+        common_flags += [
+            '-fsanitize-coverage=trace-pc-guard,indirect-calls,trace-cmp'
+        ]
+    if args.fuzzer:
+        common_flags += ['-fsanitize=fuzzer']
+        args.lib_fuzzing_engine = ''
+
+    mflags += ['LIB_FUZZING_ENGINE={}'.format(args.lib_fuzzing_engine)]
+
+    if args.sanitize_recover:
+        recover_flags = ['-fsanitize-recover=all']
+    else:
+        recover_flags = ['-fno-sanitize-recover=all']
+    if args.sanitize:
+        common_flags += recover_flags
+
+    if args.msan:
+        msan_flags = ['-fsanitize=memory']
+        if args.msan_track_origins:
+            msan_flags += ['-fsanitize-memory-track-origins']
+        common_flags += msan_flags
+        # Append extra MSAN flags (it might require special setup)
+        cppflags += [args.msan_extra_cppflags]
+        cflags += [args.msan_extra_cflags]
+        cxxflags += [args.msan_extra_cxxflags]
+        ldflags += [args.msan_extra_ldflags]
+
+    if args.asan:
+        common_flags += ['-fsanitize=address']
+
+    if args.ubsan:
+        ubsan_flags = ['-fsanitize=undefined']
+        if not args.ubsan_pointer_overflow:
+            ubsan_flags += overflow_ubsan_flags(cc, cxx)
+        common_flags += ubsan_flags
+
+    if args.stateful_fuzzing:
+        cppflags += ['-DSTATEFUL_FUZZING']
+
+    if args.fuzzing_mode:
+        cppflags += ['-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION']
+
+    if args.lib_fuzzing_engine == 'libregression.a':
+        targets = ['libregression.a'] + targets
+
+    # Append the common flags
+    cflags += common_flags
+    cxxflags += common_flags
+
+    # Prepare the flags for Make
+    cc_str = "CC={}".format(cc)
+    cxx_str = "CXX={}".format(cxx)
+    cppflags_str = "CPPFLAGS={}".format(' '.join(cppflags))
+    cflags_str = "CFLAGS={}".format(' '.join(cflags))
+    cxxflags_str = "CXXFLAGS={}".format(' '.join(cxxflags))
+    ldflags_str = "LDFLAGS={}".format(' '.join(ldflags))
+
+    # Print the flags
+    print('MFLAGS={}'.format(' '.join(mflags)))
+    print(cc_str)
+    print(cxx_str)
+    print(cppflags_str)
+    print(cflags_str)
+    print(cxxflags_str)
+    print(ldflags_str)
+
+    # Clean and build
+    clean_cmd = ['make', 'clean'] + mflags
+    print(' '.join(clean_cmd))
+    subprocess.check_call(clean_cmd)
+    build_cmd = [
+        'make',
+        cc_str,
+        cxx_str,
+        cppflags_str,
+        cflags_str,
+        cxxflags_str,
+        ldflags_str,
+    ] + mflags + targets
+    print(' '.join(build_cmd))
+    subprocess.check_call(build_cmd)
+    return 0
+
+
+def libfuzzer_parser(args):
+    description = """
+    Runs a libfuzzer binary.
+    Passes all extra arguments to libfuzzer.
+    The fuzzer should have been build with LIB_FUZZING_ENGINE pointing to
+    libFuzzer.a.
+    Generates output in the CORPORA directory, puts crashes in the ARTIFACT
+    directory, and takes extra input from the SEED directory.
+    To merge AFL's output pass the SEED as AFL's output directory and pass
+    '-merge=1'.
+    """
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        '--corpora',
+        type=str,
+        help='Override the default corpora dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET')))
+    parser.add_argument(
+        '--artifact',
+        type=str,
+        help='Override the default artifact dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET-crash')))
+    parser.add_argument(
+        '--seed',
+        type=str,
+        help='Override the default seed dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET-seed')))
+    parser.add_argument(
+        'TARGET',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(TARGETS)))
+    args, extra = parser.parse_known_args(args)
+    args.extra = extra
+
+    if args.TARGET and args.TARGET not in TARGETS:
+        raise RuntimeError('{} is not a valid target'.format(args.TARGET))
+
+    return args
+
+
+def libfuzzer(target, corpora=None, artifact=None, seed=None, extra_args=None):
+    if corpora is None:
+        corpora = abs_join(CORPORA_DIR, target)
+    if artifact is None:
+        artifact = abs_join(CORPORA_DIR, '{}-crash'.format(target))
+    if seed is None:
+        seed = abs_join(CORPORA_DIR, '{}-seed'.format(target))
+    if extra_args is None:
+        extra_args = []
+
+    target = abs_join(FUZZ_DIR, target)
+
+    corpora = [create(corpora)]
+    artifact = create(artifact)
+    seed = check(seed)
+
+    corpora += [artifact]
+    if seed is not None:
+        corpora += [seed]
+
+    cmd = [target, '-artifact_prefix={}/'.format(artifact)]
+    cmd += corpora + extra_args
+    print(' '.join(cmd))
+    subprocess.check_call(cmd)
+
+
+def libfuzzer_cmd(args):
+    try:
+        args = libfuzzer_parser(args)
+    except Exception as e:
+        print(e)
+        return 1
+    libfuzzer(args.TARGET, args.corpora, args.artifact, args.seed, args.extra)
+    return 0
+
+
+def afl_parser(args):
+    description = """
+    Runs an afl-fuzz job.
+    Passes all extra arguments to afl-fuzz.
+    The fuzzer should have been built with CC/CXX set to the AFL compilers,
+    and with LIB_FUZZING_ENGINE='libregression.a'.
+    Takes input from CORPORA and writes output to OUTPUT.
+    Uses AFL_FUZZ as the binary (set from flag or environment variable).
+    """
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        '--corpora',
+        type=str,
+        help='Override the default corpora dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET')))
+    parser.add_argument(
+        '--output',
+        type=str,
+        help='Override the default AFL output dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET-afl')))
+    parser.add_argument(
+        '--afl-fuzz',
+        type=str,
+        default=AFL_FUZZ,
+        help='AFL_FUZZ (default: $AFL_FUZZ={})'.format(AFL_FUZZ))
+    parser.add_argument(
+        'TARGET',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(TARGETS)))
+    args, extra = parser.parse_known_args(args)
+    args.extra = extra
+
+    if args.TARGET and args.TARGET not in TARGETS:
+        raise RuntimeError('{} is not a valid target'.format(args.TARGET))
+
+    if not args.corpora:
+        args.corpora = abs_join(CORPORA_DIR, args.TARGET)
+    if not args.output:
+        args.output = abs_join(CORPORA_DIR, '{}-afl'.format(args.TARGET))
+
+    return args
+
+
+def afl(args):
+    try:
+        args = afl_parser(args)
+    except Exception as e:
+        print(e)
+        return 1
+    target = abs_join(FUZZ_DIR, args.TARGET)
+
+    corpora = create(args.corpora)
+    output = create(args.output)
+
+    cmd = [args.afl_fuzz, '-i', corpora, '-o', output] + args.extra
+    cmd += [target, '@@']
+    print(' '.join(cmd))
+    subprocess.call(cmd)
+    return 0
+
+
+def regression(args):
+    try:
+        description = """
+        Runs one or more regression tests.
+        The fuzzer should have been built with with
+        LIB_FUZZING_ENGINE='libregression.a'.
+        Takes input from CORPORA.
+        """
+        args = targets_parser(args, description)
+    except Exception as e:
+        print(e)
+        return 1
+    for target in args.TARGET:
+        corpora = create(abs_join(CORPORA_DIR, target))
+        target = abs_join(FUZZ_DIR, target)
+        cmd = [target, corpora]
+        print(' '.join(cmd))
+        subprocess.check_call(cmd)
+    return 0
+
+
+def gen_parser(args):
+    description = """
+    Generate a seed corpus appropriate for TARGET with data generated with
+    decodecorpus.
+    The fuzz inputs are prepended with a seed before the zstd data, so the
+    output of decodecorpus shouldn't be used directly.
+    Generates NUMBER samples prepended with FUZZ_RNG_SEED_SIZE random bytes and
+    puts the output in SEED.
+    DECODECORPUS is the decodecorpus binary, and must already be built.
+    """
+    parser = argparse.ArgumentParser(prog=args.pop(0), description=description)
+    parser.add_argument(
+        '--number',
+        '-n',
+        type=int,
+        default=100,
+        help='Number of samples to generate')
+    parser.add_argument(
+        '--max-size-log',
+        type=int,
+        default=18,
+        help='Maximum sample size to generate')
+    parser.add_argument(
+        '--seed',
+        type=str,
+        help='Override the default seed dir (default: {})'.format(
+            abs_join(CORPORA_DIR, 'TARGET-seed')))
+    parser.add_argument(
+        '--decodecorpus',
+        type=str,
+        default=DECODECORPUS,
+        help="decodecorpus binary (default: $DECODECORPUS='{}')".format(
+            DECODECORPUS))
+    parser.add_argument(
+        '--zstd',
+        type=str,
+        default=ZSTD,
+        help="zstd binary (default: $ZSTD='{}')".format(ZSTD))
+    parser.add_argument(
+        '--fuzz-rng-seed-size',
+        type=int,
+        default=4,
+        help="FUZZ_RNG_SEED_SIZE used for generate the samples (must match)"
+    )
+    parser.add_argument(
+        'TARGET',
+        type=str,
+        help='Fuzz target(s) to build {{{}}}'.format(', '.join(TARGETS)))
+    args, extra = parser.parse_known_args(args)
+    args.extra = extra
+
+    if args.TARGET and args.TARGET not in TARGETS:
+        raise RuntimeError('{} is not a valid target'.format(args.TARGET))
+
+    if not args.seed:
+        args.seed = abs_join(CORPORA_DIR, '{}-seed'.format(args.TARGET))
+
+    if not os.path.isfile(args.decodecorpus):
+        raise RuntimeError("{} is not a file run 'make -C {} decodecorpus'".
+                           format(args.decodecorpus, abs_join(FUZZ_DIR, '..')))
+
+    return args
+
+
+def gen(args):
+    try:
+        args = gen_parser(args)
+    except Exception as e:
+        print(e)
+        return 1
+
+    seed = create(args.seed)
+    with tmpdir() as compressed, tmpdir() as decompressed, tmpdir() as dict:
+        info = TARGET_INFO[args.TARGET]
+
+        if info.input_type == InputType.DICTIONARY_DATA:
+            number = max(args.number, 1000)
+        else:
+            number = args.number
+        cmd = [
+            args.decodecorpus,
+            '-n{}'.format(args.number),
+            '-p{}/'.format(compressed),
+            '-o{}'.format(decompressed),
+        ]
+
+        if info.frame_type == FrameType.BLOCK:
+            cmd += [
+                '--gen-blocks',
+                '--max-block-size-log={}'.format(min(args.max_size_log, 17))
+            ]
+        else:
+            cmd += ['--max-content-size-log={}'.format(args.max_size_log)]
+
+        print(' '.join(cmd))
+        subprocess.check_call(cmd)
+
+        if info.input_type == InputType.RAW_DATA:
+            print('using decompressed data in {}'.format(decompressed))
+            samples = decompressed
+        elif info.input_type == InputType.COMPRESSED_DATA:
+            print('using compressed data in {}'.format(compressed))
+            samples = compressed
+        else:
+            assert info.input_type == InputType.DICTIONARY_DATA
+            print('making dictionary data from {}'.format(decompressed))
+            samples = dict
+            min_dict_size_log = 9
+            max_dict_size_log = max(min_dict_size_log + 1, args.max_size_log)
+            for dict_size_log in range(min_dict_size_log, max_dict_size_log):
+                dict_size = 1 << dict_size_log
+                cmd = [
+                    args.zstd,
+                    '--train',
+                    '-r', decompressed,
+                    '--maxdict={}'.format(dict_size),
+                    '-o', abs_join(dict, '{}.zstd-dict'.format(dict_size))
+                ]
+                print(' '.join(cmd))
+                subprocess.check_call(cmd)
+
+        # Copy the samples over and prepend the RNG seeds
+        for name in os.listdir(samples):
+            samplename = abs_join(samples, name)
+            outname = abs_join(seed, name)
+            with open(samplename, 'rb') as sample:
+                with open(outname, 'wb') as out:
+                    CHUNK_SIZE = 131072
+                    chunk = sample.read(CHUNK_SIZE)
+                    while len(chunk) > 0:
+                        out.write(chunk)
+                        chunk = sample.read(CHUNK_SIZE)
+    return 0
+
+
+def minimize(args):
+    try:
+        description = """
+        Runs a libfuzzer fuzzer with -merge=1 to build a minimal corpus in
+        TARGET_seed_corpus. All extra args are passed to libfuzzer.
+        """
+        args = targets_parser(args, description)
+    except Exception as e:
+        print(e)
+        return 1
+
+    for target in args.TARGET:
+        # Merge the corpus + anything else into the seed_corpus
+        corpus = abs_join(CORPORA_DIR, target)
+        seed_corpus = abs_join(CORPORA_DIR, "{}_seed_corpus".format(target))
+        extra_args = [corpus, "-merge=1"] + args.extra
+        libfuzzer(target, corpora=seed_corpus, extra_args=extra_args)
+        seeds = set(os.listdir(seed_corpus))
+        # Copy all crashes directly into the seed_corpus if not already present
+        crashes = abs_join(CORPORA_DIR, '{}-crash'.format(target))
+        for crash in os.listdir(crashes):
+            if crash not in seeds:
+                shutil.copy(abs_join(crashes, crash), seed_corpus)
+                seeds.add(crash)
+
+
+def zip_cmd(args):
+    try:
+        description = """
+        Zips up the seed corpus.
+        """
+        args = targets_parser(args, description)
+    except Exception as e:
+        print(e)
+        return 1
+
+    for target in args.TARGET:
+        # Zip the seed_corpus
+        seed_corpus = abs_join(CORPORA_DIR, "{}_seed_corpus".format(target))
+        zip_file = "{}.zip".format(seed_corpus)
+        cmd = ["zip", "-r", "-q", "-j", "-9", zip_file, "."]
+        print(' '.join(cmd))
+        subprocess.check_call(cmd, cwd=seed_corpus)
+
+
+def list_cmd(args):
+    print("\n".join(TARGETS))
+
+
+def short_help(args):
+    name = args[0]
+    print("Usage: {} [OPTIONS] COMMAND [ARGS]...\n".format(name))
+
+
+def help(args):
+    short_help(args)
+    print("\tfuzzing helpers (select a command and pass -h for help)\n")
+    print("Options:")
+    print("\t-h, --help\tPrint this message")
+    print("")
+    print("Commands:")
+    print("\tbuild\t\tBuild a fuzzer")
+    print("\tlibfuzzer\tRun a libFuzzer fuzzer")
+    print("\tafl\t\tRun an AFL fuzzer")
+    print("\tregression\tRun a regression test")
+    print("\tgen\t\tGenerate a seed corpus for a fuzzer")
+    print("\tminimize\tMinimize the test corpora")
+    print("\tzip\t\tZip the minimized corpora up")
+    print("\tlist\t\tList the available targets")
+
+
+def main():
+    args = sys.argv
+    if len(args) < 2:
+        help(args)
+        return 1
+    if args[1] == '-h' or args[1] == '--help' or args[1] == '-H':
+        help(args)
+        return 1
+    command = args.pop(1)
+    args[0] = "{} {}".format(args[0], command)
+    if command == "build":
+        return build(args)
+    if command == "libfuzzer":
+        return libfuzzer_cmd(args)
+    if command == "regression":
+        return regression(args)
+    if command == "afl":
+        return afl(args)
+    if command == "gen":
+        return gen(args)
+    if command == "minimize":
+        return minimize(args)
+    if command == "zip":
+        return zip_cmd(args)
+    if command == "list":
+        return list_cmd(args)
+    short_help(args)
+    print("Error: No such command {} (pass -h for help)".format(command))
+    return 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/src/zstd/tests/fuzz/fuzz_data_producer.c b/src/zstd/tests/fuzz/fuzz_data_producer.c
new file mode 100644
index 000000000..6518af309
--- /dev/null
+++ b/src/zstd/tests/fuzz/fuzz_data_producer.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include "fuzz_data_producer.h"
+
+struct FUZZ_dataProducer_s{
+  const uint8_t *data;
+  size_t size;
+};
+
+FUZZ_dataProducer_t *FUZZ_dataProducer_create(const uint8_t *data, size_t size) {
+    FUZZ_dataProducer_t *producer = FUZZ_malloc(sizeof(FUZZ_dataProducer_t));
+
+    producer->data = data;
+    producer->size = size;
+    return producer;
+}
+
+void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer) { free(producer); }
+
+uint32_t FUZZ_dataProducer_uint32Range(FUZZ_dataProducer_t *producer, uint32_t min,
+                                  uint32_t max) {
+    FUZZ_ASSERT(min <= max);
+
+    uint32_t range = max - min;
+    uint32_t rolling = range;
+    uint32_t result = 0;
+
+    while (rolling > 0 && producer->size > 0) {
+      uint8_t next = *(producer->data + producer->size - 1);
+      producer->size -= 1;
+      result = (result << 8) | next;
+      rolling >>= 8;
+    }
+
+    if (range == 0xffffffff) {
+      return result;
+    }
+
+    return min + result % (range + 1);
+}
+
+uint32_t FUZZ_dataProducer_uint32(FUZZ_dataProducer_t *producer) {
+    return FUZZ_dataProducer_uint32Range(producer, 0, 0xffffffff);
+}
+
+int32_t FUZZ_dataProducer_int32Range(FUZZ_dataProducer_t *producer,
+                                    int32_t min, int32_t max)
+{
+    FUZZ_ASSERT(min <= max);
+
+    if (min < 0)
+      return (int)FUZZ_dataProducer_uint32Range(producer, 0, max - min) + min;
+
+    return FUZZ_dataProducer_uint32Range(producer, min, max);
+}
+
+size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer){
+    return producer->size;
+}
+
+size_t FUZZ_dataProducer_contract(FUZZ_dataProducer_t *producer, size_t newSize)
+{
+    newSize = newSize > producer->size ? producer->size : newSize;
+
+    size_t remaining = producer->size - newSize;
+    producer->data = producer->data + remaining;
+    producer->size = newSize;
+    return remaining;
+}
+
+size_t FUZZ_dataProducer_reserveDataPrefix(FUZZ_dataProducer_t *producer)
+{
+    size_t producerSliceSize = FUZZ_dataProducer_uint32Range(
+                                  producer, 0, producer->size);
+    return FUZZ_dataProducer_contract(producer, producerSliceSize);
+}
diff --git a/src/zstd/tests/fuzz/fuzz_data_producer.h b/src/zstd/tests/fuzz/fuzz_data_producer.h
new file mode 100644
index 000000000..41e0b52d5
--- /dev/null
+++ b/src/zstd/tests/fuzz/fuzz_data_producer.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * Helper APIs for generating random data from input data stream.
+ The producer reads bytes from the end of the input and appends them together
+ to generate  a random number in the requested range. If it runs out of input
+ data, it will keep returning the same value (min) over and over again.
+
+ */
+
+#ifndef FUZZ_DATA_PRODUCER_H
+#define FUZZ_DATA_PRODUCER_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "fuzz_helpers.h"
+
+/* Struct used for maintaining the state of the data */
+typedef struct FUZZ_dataProducer_s FUZZ_dataProducer_t;
+
+/* Returns a data producer state struct. Use for producer initialization. */
+FUZZ_dataProducer_t *FUZZ_dataProducer_create(const uint8_t *data, size_t size);
+
+/* Frees the data producer */
+void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer);
+
+/* Returns value between [min, max] */
+uint32_t FUZZ_dataProducer_uint32Range(FUZZ_dataProducer_t *producer, uint32_t min,
+                                  uint32_t max);
+
+/* Returns a uint32 value */
+uint32_t FUZZ_dataProducer_uint32(FUZZ_dataProducer_t *producer);
+
+/* Returns a signed value between [min, max] */
+int32_t FUZZ_dataProducer_int32Range(FUZZ_dataProducer_t *producer,
+                                    int32_t min, int32_t max);
+
+/* Returns the size of the remaining bytes of data in the producer */
+size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer);
+
+/* Restricts the producer to only the last newSize bytes of data.
+If newSize > current data size, nothing happens. Returns the number of bytes
+the producer won't use anymore, after contracting. */
+size_t FUZZ_dataProducer_contract(FUZZ_dataProducer_t *producer, size_t newSize);
+
+/* Restricts the producer to use only the last X bytes of data, where X is
+ a random number in the interval [0, data_size]. Returns the size of the
+ remaining data the producer won't use anymore (the prefix). */
+size_t FUZZ_dataProducer_reserveDataPrefix(FUZZ_dataProducer_t *producer);
+#endif // FUZZ_DATA_PRODUCER_H
diff --git a/src/zstd/tests/fuzz/fuzz_helpers.c b/src/zstd/tests/fuzz/fuzz_helpers.c
new file mode 100644
index 000000000..b80dc7571
--- /dev/null
+++ b/src/zstd/tests/fuzz/fuzz_helpers.c
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+#include "fuzz_helpers.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+void* FUZZ_malloc(size_t size)
+{
+    if (size > 0) {
+        void* const mem = malloc(size);
+        FUZZ_ASSERT(mem);
+        return mem;
+    }
+    return NULL;
+}
+
+int FUZZ_memcmp(void const* lhs, void const* rhs, size_t size)
+{
+    if (size == 0) {
+        return 0;
+    }
+    return memcmp(lhs, rhs, size);
+}
\ No newline at end of file
diff --git a/src/zstd/tests/fuzz/fuzz_helpers.h b/src/zstd/tests/fuzz/fuzz_helpers.h
new file mode 100644
index 000000000..cde2c4ea7
--- /dev/null
+++ b/src/zstd/tests/fuzz/fuzz_helpers.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * Helper functions for fuzzing.
+ */
+
+#ifndef FUZZ_HELPERS_H
+#define FUZZ_HELPERS_H
+
+#include "debug.h"
+#include "fuzz.h"
+#include "xxhash.h"
+#include "zstd.h"
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+
+#define FUZZ_QUOTE_IMPL(str) #str
+#define FUZZ_QUOTE(str) FUZZ_QUOTE_IMPL(str)
+
+/**
+ * Asserts for fuzzing that are always enabled.
+ */
+#define FUZZ_ASSERT_MSG(cond, msg)                                             \
+  ((cond) ? (void)0                                                            \
+          : (fprintf(stderr, "%s: %u: Assertion: `%s' failed. %s\n", __FILE__, \
+                     __LINE__, FUZZ_QUOTE(cond), (msg)),                       \
+             abort()))
+#define FUZZ_ASSERT(cond) FUZZ_ASSERT_MSG((cond), "");
+#define FUZZ_ZASSERT(code)                                                     \
+  FUZZ_ASSERT_MSG(!ZSTD_isError(code), ZSTD_getErrorName(code))
+
+#if defined(__GNUC__)
+#define FUZZ_STATIC static __inline __attribute__((unused))
+#elif defined(__cplusplus) ||                                                  \
+    (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
+#define FUZZ_STATIC static inline
+#elif defined(_MSC_VER)
+#define FUZZ_STATIC static __inline
+#else
+#define FUZZ_STATIC static
+#endif
+
+/**
+ * malloc except return NULL for zero sized data and FUZZ_ASSERT
+ * that malloc doesn't fail.
+ */
+void* FUZZ_malloc(size_t size);
+
+/**
+ * memcmp but accepts NULL.
+ */
+int FUZZ_memcmp(void const* lhs, void const* rhs, size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/zstd/tests/fuzz/raw_dictionary_round_trip.c b/src/zstd/tests/fuzz/raw_dictionary_round_trip.c
new file mode 100644
index 000000000..08e5fd9ed
--- /dev/null
+++ b/src/zstd/tests/fuzz/raw_dictionary_round_trip.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress) with
+ * a raw content dictionary, compares the result with the original, and calls
+ * abort() on corruption.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+
+static size_t roundTripTest(void *result, size_t resultCapacity,
+                            void *compressed, size_t compressedCapacity,
+                            const void *src, size_t srcSize,
+                            const void *dict, size_t dictSize,
+                            FUZZ_dataProducer_t *producer)
+{
+    ZSTD_dictContentType_e const dictContentType = ZSTD_dct_rawContent;
+    int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
+    size_t cSize;
+
+    FUZZ_setRandomParameters(cctx, srcSize, producer);
+    /* Disable checksum so we can use sizes smaller than compress bound. */
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 0));
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
+            cctx, dict, dictSize,
+            ZSTD_dct_rawContent));
+    else 
+        FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
+            cctx, dict, dictSize,
+            (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+            ZSTD_dct_rawContent));
+    cSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+    FUZZ_ZASSERT(cSize);
+
+    if (refPrefix)
+        FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
+            dctx, dict, dictSize,
+            dictContentType));
+    else
+        FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
+            dctx, dict, dictSize,
+            (ZSTD_dictLoadMethod_e)FUZZ_dataProducer_uint32Range(producer, 0, 1),
+            dictContentType));
+    {
+        size_t const ret = ZSTD_decompressDCtx(
+                dctx, result, resultCapacity, compressed, cSize);
+        return ret;
+    }
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    uint8_t const* const srcBuf = src;
+    size_t const srcSize = FUZZ_dataProducer_uint32Range(producer, 0, size);
+    uint8_t const* const dictBuf = srcBuf + srcSize;
+    size_t const dictSize = size - srcSize;
+    size_t const decompSize = srcSize;
+    void* const decompBuf = FUZZ_malloc(decompSize);
+    size_t compSize = ZSTD_compressBound(srcSize);
+    void* compBuf;
+    /* Half of the time fuzz with a 1 byte smaller output size.
+     * This will still succeed because we force the checksum to be disabled,
+     * giving us 4 bytes of overhead.
+     */
+    compSize -= FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    compBuf = FUZZ_malloc(compSize);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const result =
+            roundTripTest(decompBuf, decompSize, compBuf, compSize, srcBuf, srcSize, dictBuf, dictSize, producer);
+        FUZZ_ZASSERT(result);
+        FUZZ_ASSERT_MSG(result == srcSize, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, decompBuf, srcSize), "Corruption!");
+    }
+    free(decompBuf);
+    free(compBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/regression_driver.c b/src/zstd/tests/fuzz/regression_driver.c
new file mode 100644
index 000000000..8180ca822
--- /dev/null
+++ b/src/zstd/tests/fuzz/regression_driver.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#include "fuzz.h"
+#include "fuzz_helpers.h"
+#include "util.h"
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char const **argv) {
+  size_t const kMaxFileSize = (size_t)1 << 27;
+  int const kFollowLinks = 1;
+  FileNamesTable* files;
+  const char** const fnTable = argv + 1;
+  uint8_t *buffer = NULL;
+  size_t bufferSize = 0;
+  unsigned i;
+  unsigned numFilesTested = 0;
+  int ret = 0;
+
+  {
+    unsigned const numFiles = (unsigned)(argc - 1);
+#ifdef UTIL_HAS_CREATEFILELIST
+    files = UTIL_createExpandedFNT(fnTable, numFiles, kFollowLinks);
+#else
+    files = UTIL_createFNT_fromROTable(fnTable, numFiles);
+    assert(numFiles == files->tableSize);
+#endif
+  }
+  if (!files) {
+    fprintf(stderr, "ERROR: Failed to create file names table\n");
+    return 1;
+  }
+  if (files->tableSize == 0)
+    fprintf(stderr, "WARNING: No files passed to %s\n", argv[0]);
+  for (i = 0; i < files->tableSize; ++i) {
+    char const *fileName = files->fileNames[i];
+    DEBUGLOG(3, "Running %s", fileName);
+    size_t const fileSize = UTIL_getFileSize(fileName);
+    size_t readSize;
+    FILE *file;
+
+    /* Check that it is a regular file, and that the fileSize is valid.
+     * If it is not a regular file, then it may have been deleted since we
+     * constructed the list, so just skip it, but return an error exit code.
+     */
+    if (!UTIL_isRegularFile(fileName)) {
+      ret = 1;
+      continue;
+    }
+    FUZZ_ASSERT_MSG(fileSize <= kMaxFileSize, fileName);
+    /* Ensure we have a large enough buffer allocated */
+    if (fileSize > bufferSize) {
+      free(buffer);
+      buffer = (uint8_t *)malloc(fileSize);
+      FUZZ_ASSERT_MSG(buffer, fileName);
+      bufferSize = fileSize;
+    }
+    /* Open the file */
+    file = fopen(fileName, "rb");
+    FUZZ_ASSERT_MSG(file, fileName);
+    /* Read the file */
+    readSize = fread(buffer, 1, fileSize, file);
+    FUZZ_ASSERT_MSG(readSize == fileSize, fileName);
+    /* Close the file */
+    fclose(file);
+    /* Run the fuzz target */
+    LLVMFuzzerTestOneInput(buffer, fileSize);
+    ++numFilesTested;
+  }
+  fprintf(stderr, "Tested %u files: ", numFilesTested);
+  if (ret == 0) {
+    fprintf(stderr, "Success!\n");
+  } else {
+    fprintf(stderr, "Failure!\n");
+  }
+  free(buffer);
+  UTIL_freeFileNamesTable(files);
+  return ret;
+}
diff --git a/src/zstd/tests/fuzz/simple_compress.c b/src/zstd/tests/fuzz/simple_compress.c
new file mode 100644
index 000000000..b64f373eb
--- /dev/null
+++ b/src/zstd/tests/fuzz/simple_compress.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to comprss the fuzzed data with the simple
+ * compression function with an output buffer that may be too small to
+ * ensure that the compressor never crashes.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_CCtx *cctx = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    size_t const maxSize = ZSTD_compressBound(size);
+    size_t const bufSize = FUZZ_dataProducer_uint32Range(producer, 0, maxSize);
+
+    int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+
+    void *rBuf = FUZZ_malloc(bufSize);
+    ZSTD_compressCCtx(cctx, rBuf, bufSize, src, size, cLevel);
+    free(rBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/simple_decompress.c b/src/zstd/tests/fuzz/simple_decompress.c
new file mode 100644
index 000000000..c3903ce8b
--- /dev/null
+++ b/src/zstd/tests/fuzz/simple_decompress.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the simple
+ * decompression function to ensure the decompressor never crashes.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_DCtx *dctx = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    size_t const bufSize = FUZZ_dataProducer_uint32Range(producer, 0, 10 * size);
+    void *rBuf = FUZZ_malloc(bufSize);
+
+    ZSTD_decompressDCtx(dctx, rBuf, bufSize, src, size);
+    free(rBuf);
+
+    FUZZ_dataProducer_free(producer);
+
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/simple_round_trip.c b/src/zstd/tests/fuzz/simple_round_trip.c
new file mode 100644
index 000000000..2f008d06a
--- /dev/null
+++ b/src/zstd/tests/fuzz/simple_round_trip.c
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+static ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+
+static size_t roundTripTest(void *result, size_t resultCapacity,
+                            void *compressed, size_t compressedCapacity,
+                            const void *src, size_t srcSize,
+                            FUZZ_dataProducer_t *producer)
+{
+    size_t cSize;
+    size_t dSize;
+    int targetCBlockSize = 0;
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1)) {
+        FUZZ_setRandomParameters(cctx, srcSize, producer);
+        cSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+        FUZZ_ZASSERT(ZSTD_CCtx_getParameter(cctx, ZSTD_c_targetCBlockSize, &targetCBlockSize));
+    } else {
+      int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);
+
+        cSize = ZSTD_compressCCtx(
+            cctx, compressed, compressedCapacity, src, srcSize, cLevel);
+    }
+    FUZZ_ZASSERT(cSize);
+    dSize = ZSTD_decompressDCtx(dctx, result, resultCapacity, compressed, cSize);
+    FUZZ_ZASSERT(dSize);
+    /* When superblock is enabled make sure we don't expand the block more than expected. */
+    if (targetCBlockSize != 0) {
+        size_t normalCSize;
+        FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, ZSTD_c_targetCBlockSize, 0));
+        normalCSize = ZSTD_compress2(cctx, compressed, compressedCapacity, src, srcSize);
+        FUZZ_ZASSERT(normalCSize);
+        {
+            size_t const bytesPerBlock = 3 /* block header */
+                + 5 /* Literal header */
+                + 6 /* Huffman jump table */
+                + 3 /* number of sequences */
+                + 1 /* symbol compression modes */;
+            size_t const expectedExpansion = bytesPerBlock * (1 + (normalCSize / MAX(1, targetCBlockSize)));
+            size_t const allowedExpansion = (srcSize >> 3) + 5 * expectedExpansion + 10;
+            FUZZ_ASSERT(cSize <= normalCSize + allowedExpansion);
+        }
+    }
+    return dSize;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    size_t const rBufSize = size;
+    void* rBuf = FUZZ_malloc(rBufSize);
+    size_t cBufSize = ZSTD_compressBound(size);
+    void* cBuf;
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    /* Half of the time fuzz with a 1 byte smaller output size.
+     * This will still succeed because we don't use a dictionary, so the dictID
+     * field is empty, giving us 4 bytes of overhead.
+     */
+    cBufSize -= FUZZ_dataProducer_uint32Range(producer, 0, 1);
+
+    cBuf = FUZZ_malloc(cBufSize);
+
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const result =
+            roundTripTest(rBuf, rBufSize, cBuf, cBufSize, src, size, producer);
+        FUZZ_ZASSERT(result);
+        FUZZ_ASSERT_MSG(result == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+    }
+    free(rBuf);
+    free(cBuf);
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/stream_decompress.c b/src/zstd/tests/fuzz/stream_decompress.c
new file mode 100644
index 000000000..25901b1eb
--- /dev/null
+++ b/src/zstd/tests/fuzz/stream_decompress.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target attempts to decompress the fuzzed data with the simple
+ * decompression function to ensure the decompressor never crashes.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "fuzz_data_producer.h"
+
+static size_t const kBufSize = ZSTD_BLOCKSIZE_MAX;
+
+static ZSTD_DStream *dstream = NULL;
+static void* buf = NULL;
+uint32_t seed;
+
+static ZSTD_outBuffer makeOutBuffer(FUZZ_dataProducer_t *producer, uint32_t min)
+{
+  ZSTD_outBuffer buffer = { buf, 0, 0 };
+
+  buffer.size = (FUZZ_dataProducer_uint32Range(producer, min, kBufSize));
+  FUZZ_ASSERT(buffer.size <= kBufSize);
+
+  if (buffer.size == 0) {
+    buffer.dst = NULL;
+  }
+
+  return buffer;
+}
+
+static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size,
+                                  FUZZ_dataProducer_t *producer,
+                                  uint32_t min)
+{
+  ZSTD_inBuffer buffer = { *src, 0, 0 };
+
+  FUZZ_ASSERT(*size > 0);
+  buffer.size = (FUZZ_dataProducer_uint32Range(producer, min, *size));
+  FUZZ_ASSERT(buffer.size <= *size);
+  *src += buffer.size;
+  *size -= buffer.size;
+
+  if (buffer.size == 0) {
+    buffer.src = NULL;
+  }
+
+  return buffer;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    /* Guarantee forward progress by refusing to generate 2 zero sized
+     * buffers in a row. */
+    int prevInWasZero = 0;
+    int prevOutWasZero = 0;
+    int stableOutBuffer;
+    ZSTD_outBuffer out;
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (!buf) {
+        buf = FUZZ_malloc(kBufSize);
+    }
+
+    if (!dstream) {
+        dstream = ZSTD_createDStream();
+        FUZZ_ASSERT(dstream);
+    } else {
+        FUZZ_ZASSERT(ZSTD_DCtx_reset(dstream, ZSTD_reset_session_only));
+    }
+
+    stableOutBuffer = FUZZ_dataProducer_uint32Range(producer, 0, 10) == 5;
+    if (stableOutBuffer) {
+      FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dstream, ZSTD_d_stableOutBuffer, 1));
+      out.dst = buf;
+      out.size = kBufSize;
+      out.pos = 0;
+    }
+
+    while (size > 0) {
+        ZSTD_inBuffer in = makeInBuffer(&src, &size, producer, prevInWasZero ? 1 : 0);
+        prevInWasZero = in.size == 0;
+        while (in.pos != in.size) {
+            if (!stableOutBuffer || prevOutWasZero || FUZZ_dataProducer_uint32Range(producer, 0, 100) == 55) {
+              out = makeOutBuffer(producer, prevOutWasZero ? 1 : 0);
+            }
+            prevOutWasZero = out.size == 0;
+            size_t const rc = ZSTD_decompressStream(dstream, &out, &in);
+            if (ZSTD_isError(rc)) goto error;
+        }
+    }
+
+error:
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeDStream(dstream); dstream = NULL;
+#endif
+    FUZZ_dataProducer_free(producer);
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/stream_round_trip.c b/src/zstd/tests/fuzz/stream_round_trip.c
new file mode 100644
index 000000000..286d3871b
--- /dev/null
+++ b/src/zstd/tests/fuzz/stream_round_trip.c
@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target performs a zstd round-trip test (compress & decompress),
+ * compares the result with the original, and calls abort() on corruption.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+#include "fuzz_data_producer.h"
+
+ZSTD_CCtx *cctx = NULL;
+static ZSTD_DCtx *dctx = NULL;
+static uint8_t* cBuf = NULL;
+static uint8_t* rBuf = NULL;
+static size_t bufSize = 0;
+
+static ZSTD_outBuffer makeOutBuffer(uint8_t *dst, size_t capacity,
+                                    FUZZ_dataProducer_t *producer)
+{
+    ZSTD_outBuffer buffer = { dst, 0, 0 };
+
+    FUZZ_ASSERT(capacity > 0);
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, capacity));
+    FUZZ_ASSERT(buffer.size <= capacity);
+
+    return buffer;
+}
+
+static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size,
+                                  FUZZ_dataProducer_t *producer)
+{
+    ZSTD_inBuffer buffer = { *src, 0, 0 };
+
+    FUZZ_ASSERT(*size > 0);
+    buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, *size));
+    FUZZ_ASSERT(buffer.size <= *size);
+    *src += buffer.size;
+    *size -= buffer.size;
+
+    return buffer;
+}
+
+static size_t compress(uint8_t *dst, size_t capacity,
+                       const uint8_t *src, size_t srcSize,
+                     FUZZ_dataProducer_t *producer)
+{
+    size_t dstSize = 0;
+    ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+    FUZZ_setRandomParameters(cctx, srcSize, producer);
+
+    while (srcSize > 0) {
+        ZSTD_inBuffer in = makeInBuffer(&src, &srcSize, producer);
+        /* Mode controls the action. If mode == -1 we pick a new mode */
+        int mode = -1;
+        while (in.pos < in.size || mode != -1) {
+            ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
+            /* Previous action finished, pick a new mode. */
+            if (mode == -1) mode = FUZZ_dataProducer_uint32Range(producer, 0, 9);
+            switch (mode) {
+                case 0: /* fall-through */
+                case 1: /* fall-through */
+                case 2: {
+                    size_t const ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush);
+                    FUZZ_ZASSERT(ret);
+                    if (ret == 0)
+                        mode = -1;
+                    break;
+                }
+                case 3: {
+                    size_t ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+                    FUZZ_ZASSERT(ret);
+                    /* Reset the compressor when the frame is finished */
+                    if (ret == 0) {
+                        ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+                        if (FUZZ_dataProducer_uint32Range(producer, 0, 7) == 0) {
+                            size_t const remaining = in.size - in.pos;
+                            FUZZ_setRandomParameters(cctx, remaining, producer);
+                        }
+                        mode = -1;
+                    }
+                    break;
+                }
+                case 4: {
+                    ZSTD_inBuffer nullIn = { NULL, 0, 0 };
+                    ZSTD_outBuffer nullOut = { NULL, 0, 0 };
+                    size_t const ret = ZSTD_compressStream2(cctx, &nullOut, &nullIn, ZSTD_e_continue);
+                    FUZZ_ZASSERT(ret);
+                }
+                /* fall-through */
+                default: {
+                    size_t const ret =
+                        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_continue);
+                    FUZZ_ZASSERT(ret);
+                    mode = -1;
+                }
+            }
+            dst += out.pos;
+            dstSize += out.pos;
+            capacity -= out.pos;
+        }
+    }
+    for (;;) {
+        ZSTD_inBuffer in = {NULL, 0, 0};
+        ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
+        size_t const ret = ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+        FUZZ_ZASSERT(ret);
+
+        dst += out.pos;
+        dstSize += out.pos;
+        capacity -= out.pos;
+        if (ret == 0)
+            break;
+    }
+    return dstSize;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    size_t neededBufSize;
+
+    /* Give a random portion of src data to the producer, to use for
+    parameter generation. The rest will be used for (de)compression */
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
+    size = FUZZ_dataProducer_reserveDataPrefix(producer);
+
+    neededBufSize = ZSTD_compressBound(size) * 15;
+
+    /* Allocate all buffers and contexts if not already allocated */
+    if (neededBufSize > bufSize) {
+        free(cBuf);
+        free(rBuf);
+        cBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
+        rBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
+        bufSize = neededBufSize;
+    }
+    if (!cctx) {
+        cctx = ZSTD_createCCtx();
+        FUZZ_ASSERT(cctx);
+    }
+    if (!dctx) {
+        dctx = ZSTD_createDCtx();
+        FUZZ_ASSERT(dctx);
+    }
+
+    {
+        size_t const cSize = compress(cBuf, neededBufSize, src, size, producer);
+        size_t const rSize =
+            ZSTD_decompressDCtx(dctx, rBuf, neededBufSize, cBuf, cSize);
+        FUZZ_ZASSERT(rSize);
+        FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
+        FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
+    }
+
+    FUZZ_dataProducer_free(producer);
+#ifndef STATEFUL_FUZZING
+    ZSTD_freeCCtx(cctx); cctx = NULL;
+    ZSTD_freeDCtx(dctx); dctx = NULL;
+#endif
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/zstd_frame_info.c b/src/zstd/tests/fuzz/zstd_frame_info.c
new file mode 100644
index 000000000..876a74e9a
--- /dev/null
+++ b/src/zstd/tests/fuzz/zstd_frame_info.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/**
+ * This fuzz target fuzzes all of the helper functions that consume compressed
+ * input.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "fuzz_helpers.h"
+#include "zstd_helpers.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
+{
+    ZSTD_frameHeader zfh;
+    if (size == 0) {
+        src = NULL;
+   }
+    /* You can fuzz any helper functions here that are fast, and take zstd
+     * compressed data as input. E.g. don't expect the input to be a dictionary,
+     * so don't fuzz ZSTD_getDictID_fromDict().
+     */
+    ZSTD_getFrameContentSize(src, size);
+    ZSTD_getDecompressedSize(src, size);
+    ZSTD_findFrameCompressedSize(src, size);
+    ZSTD_getDictID_fromFrame(src, size);
+    ZSTD_findDecompressedSize(src, size);
+    ZSTD_decompressBound(src, size);
+    ZSTD_frameHeaderSize(src, size);
+    ZSTD_isFrame(src, size);
+    ZSTD_getFrameHeader(&zfh, src, size);
+    ZSTD_getFrameHeader_advanced(&zfh, src, size, ZSTD_f_zstd1);
+    return 0;
+}
diff --git a/src/zstd/tests/fuzz/zstd_helpers.c b/src/zstd/tests/fuzz/zstd_helpers.c
new file mode 100644
index 000000000..5680bd628
--- /dev/null
+++ b/src/zstd/tests/fuzz/zstd_helpers.c
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#define ZSTD_STATIC_LINKING_ONLY
+#define ZDICT_STATIC_LINKING_ONLY
+
+#include <string.h>
+
+#include "zstd_helpers.h"
+#include "fuzz_helpers.h"
+#include "zstd.h"
+#include "zdict.h"
+
+const int kMinClevel = -3;
+const int kMaxClevel = 19;
+
+static void set(ZSTD_CCtx *cctx, ZSTD_cParameter param, int value)
+{
+    FUZZ_ZASSERT(ZSTD_CCtx_setParameter(cctx, param, value));
+}
+
+static void setRand(ZSTD_CCtx *cctx, ZSTD_cParameter param, unsigned min,
+                    unsigned max, FUZZ_dataProducer_t *producer) {
+    unsigned const value = FUZZ_dataProducer_uint32Range(producer, min, max);
+    set(cctx, param, value);
+}
+
+ZSTD_compressionParameters FUZZ_randomCParams(size_t srcSize, FUZZ_dataProducer_t *producer)
+{
+    /* Select compression parameters */
+    ZSTD_compressionParameters cParams;
+    cParams.windowLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_WINDOWLOG_MIN, 15);
+    cParams.hashLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_HASHLOG_MIN, 15);
+    cParams.chainLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_CHAINLOG_MIN, 16);
+    cParams.searchLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_SEARCHLOG_MIN, 9);
+    cParams.minMatch = FUZZ_dataProducer_uint32Range(producer, ZSTD_MINMATCH_MIN,
+                                          ZSTD_MINMATCH_MAX);
+    cParams.targetLength = FUZZ_dataProducer_uint32Range(producer, 0, 512);
+    cParams.strategy = FUZZ_dataProducer_uint32Range(producer, ZSTD_STRATEGY_MIN, ZSTD_STRATEGY_MAX);
+    return ZSTD_adjustCParams(cParams, srcSize, 0);
+}
+
+ZSTD_frameParameters FUZZ_randomFParams(FUZZ_dataProducer_t *producer)
+{
+    /* Select frame parameters */
+    ZSTD_frameParameters fParams;
+    fParams.contentSizeFlag = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    fParams.checksumFlag = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    fParams.noDictIDFlag = FUZZ_dataProducer_uint32Range(producer, 0, 1);
+    return fParams;
+}
+
+ZSTD_parameters FUZZ_randomParams(size_t srcSize, FUZZ_dataProducer_t *producer)
+{
+    ZSTD_parameters params;
+    params.cParams = FUZZ_randomCParams(srcSize, producer);
+    params.fParams = FUZZ_randomFParams(producer);
+    return params;
+}
+
+void FUZZ_setRandomParameters(ZSTD_CCtx *cctx, size_t srcSize, FUZZ_dataProducer_t *producer)
+{
+    ZSTD_compressionParameters cParams = FUZZ_randomCParams(srcSize, producer);
+    set(cctx, ZSTD_c_windowLog, cParams.windowLog);
+    set(cctx, ZSTD_c_hashLog, cParams.hashLog);
+    set(cctx, ZSTD_c_chainLog, cParams.chainLog);
+    set(cctx, ZSTD_c_searchLog, cParams.searchLog);
+    set(cctx, ZSTD_c_minMatch, cParams.minMatch);
+    set(cctx, ZSTD_c_targetLength, cParams.targetLength);
+    set(cctx, ZSTD_c_strategy, cParams.strategy);
+    /* Select frame parameters */
+    setRand(cctx, ZSTD_c_contentSizeFlag, 0, 1, producer);
+    setRand(cctx, ZSTD_c_checksumFlag, 0, 1, producer);
+    setRand(cctx, ZSTD_c_dictIDFlag, 0, 1, producer);
+    /* Select long distance matching parameters */
+    setRand(cctx, ZSTD_c_enableLongDistanceMatching, 0, 1, producer);
+    setRand(cctx, ZSTD_c_ldmHashLog, ZSTD_HASHLOG_MIN, 16, producer);
+    setRand(cctx, ZSTD_c_ldmMinMatch, ZSTD_LDM_MINMATCH_MIN,
+            ZSTD_LDM_MINMATCH_MAX, producer);
+    setRand(cctx, ZSTD_c_ldmBucketSizeLog, 0, ZSTD_LDM_BUCKETSIZELOG_MAX,
+            producer);
+    setRand(cctx, ZSTD_c_ldmHashRateLog, ZSTD_LDM_HASHRATELOG_MIN,
+            ZSTD_LDM_HASHRATELOG_MAX, producer);
+    /* Set misc parameters */
+    setRand(cctx, ZSTD_c_nbWorkers, 0, 2, producer);
+    setRand(cctx, ZSTD_c_rsyncable, 0, 1, producer);
+    setRand(cctx, ZSTD_c_forceMaxWindow, 0, 1, producer);
+    setRand(cctx, ZSTD_c_literalCompressionMode, 0, 2, producer);
+    setRand(cctx, ZSTD_c_forceAttachDict, 0, 2, producer);
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0) {
+      setRand(cctx, ZSTD_c_srcSizeHint, ZSTD_SRCSIZEHINT_MIN, 2 * srcSize, producer);
+    }
+    if (FUZZ_dataProducer_uint32Range(producer, 0, 1) == 0) {
+      setRand(cctx, ZSTD_c_targetCBlockSize, ZSTD_TARGETCBLOCKSIZE_MIN, ZSTD_TARGETCBLOCKSIZE_MAX, producer);
+    }
+}
+
+FUZZ_dict_t FUZZ_train(void const* src, size_t srcSize, FUZZ_dataProducer_t *producer)
+{
+    size_t const dictSize = MAX(srcSize / 8, 1024);
+    size_t const totalSampleSize = dictSize * 11;
+    FUZZ_dict_t dict = { FUZZ_malloc(dictSize), dictSize };
+    char* const samples = (char*)FUZZ_malloc(totalSampleSize);
+    unsigned nbSamples = 100;
+    size_t* const samplesSizes = (size_t*)FUZZ_malloc(sizeof(size_t) * nbSamples);
+    size_t pos = 0;
+    size_t sample = 0;
+    ZDICT_fastCover_params_t params;
+
+    for (sample = 0; sample < nbSamples; ++sample) {
+      size_t const remaining = totalSampleSize - pos;
+      size_t const offset = FUZZ_dataProducer_uint32Range(producer, 0, MAX(srcSize, 1) - 1);
+      size_t const limit = MIN(srcSize - offset, remaining);
+      size_t const toCopy = MIN(limit, remaining / (nbSamples - sample));
+      memcpy(samples + pos, src + offset, toCopy);
+      pos += toCopy;
+      samplesSizes[sample] = toCopy;
+    }
+    memset(samples + pos, 0, totalSampleSize - pos);
+
+    memset(&params, 0, sizeof(params));
+    params.accel = 5;
+    params.k = 40;
+    params.d = 8;
+    params.f = 14;
+    params.zParams.compressionLevel = 1;
+    dict.size = ZDICT_trainFromBuffer_fastCover(dict.buff, dictSize,
+        samples, samplesSizes, nbSamples, params);
+    if (ZSTD_isError(dict.size)) {
+        free(dict.buff);
+        memset(&dict, 0, sizeof(dict));
+    }
+
+    free(samplesSizes);
+    free(samples);
+
+    return dict;
+}
diff --git a/src/zstd/tests/fuzz/zstd_helpers.h b/src/zstd/tests/fuzz/zstd_helpers.h
new file mode 100644
index 000000000..6a4e340d3
--- /dev/null
+++ b/src/zstd/tests/fuzz/zstd_helpers.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2016-2020, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+/**
+ * Helper functions for fuzzing.
+ */
+
+#ifndef ZSTD_HELPERS_H
+#define ZSTD_HELPERS_H
+
+#define ZSTD_STATIC_LINKING_ONLY
+
+#include "zstd.h"
+#include "fuzz_data_producer.h"
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const int kMinClevel;
+extern const int kMaxClevel;
+
+void FUZZ_setRandomParameters(ZSTD_CCtx *cctx, size_t srcSize, FUZZ_dataProducer_t *producer);
+
+ZSTD_compressionParameters FUZZ_randomCParams(size_t srcSize, FUZZ_dataProducer_t *producer);
+ZSTD_frameParameters FUZZ_randomFParams(FUZZ_dataProducer_t *producer);
+ZSTD_parameters FUZZ_randomParams(size_t srcSize, FUZZ_dataProducer_t *producer);
+
+typedef struct {
+  void* buff;
+  size_t size;
+} FUZZ_dict_t;
+
+/* Quickly train a dictionary from a source for fuzzing.
+ * NOTE: Don't use this to train production dictionaries, it is only optimized
+ * for speed, and doesn't care about dictionary quality.
+ */
+FUZZ_dict_t FUZZ_train(void const* src, size_t srcSize, FUZZ_dataProducer_t *producer);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZSTD_HELPERS_H */
diff --git a/src/zstd/tests/fuzzer.c b/src/zstd/tests/fuzzer.c
new file mode 100644
index 000000000..8ac2864f3
--- /dev/null
+++ b/src/zstd/tests/fuzzer.c
@@ -0,0 +1,3422 @@
+/*
+ * Copyright (c) 2015-2020, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+
+/*-************************************
+*  Compiler specific
+**************************************/
+#ifdef _MSC_VER    /* Visual Studio */
+#  define _CRT_SECURE_NO_WARNINGS   /* fgets */
+#  pragma warning(disable : 4127)   /* disable: C4127: conditional expression is constant */
+#  pragma warning(disable : 4204)   /* disable: C4204: non-constant aggregate initializer */
+#endif
+
+
+/*-************************************
+*  Includes
+**************************************/
+#include <stdlib.h>       /* free */
+#include <stdio.h>        /* fgets, sscanf */
+#include <string.h>       /* strcmp */
+#undef NDEBUG
+#include <assert.h>
+#define ZSTD_STATIC_LINKING_ONLY  /* ZSTD_compressContinue, ZSTD_compressBlock */
+#include "debug.h"        /* DEBUG_STATIC_ASSERT */
+#include "fse.h"
+#include "zstd.h"         /* ZSTD_VERSION_STRING */
+#include "zstd_errors.h"  /* ZSTD_getErrorCode */
+#include "zstdmt_compress.h"
+#define ZDICT_STATIC_LINKING_ONLY
+#include "zdict.h"        /* ZDICT_trainFromBuffer */
+#include "mem.h"
+#include "datagen.h"      /* RDG_genBuffer */
+#define XXH_STATIC_LINKING_ONLY   /* XXH64_state_t */
+#include "xxhash.h"       /* XXH64 */
+#include "util.h"
+#include "timefn.h"       /* SEC_TO_MICRO, UTIL_time_t, UTIL_TIME_INITIALIZER, UTIL_clockSpanMicro, UTIL_getTime */
+/* must be included after util.h, due to ERROR macro redefinition issue on Visual Studio */
+#include "zstd_internal.h"  /* ZSTD_WORKSPACETOOLARGE_MAXDURATION, ZSTD_WORKSPACETOOLARGE_FACTOR, KB, MB */
+
+
+/*-************************************
+*  Constants
+**************************************/
+#define GB *(1U<<30)
+
+static const int FUZ_compressibility_default = 50;
+static const int nbTestsDefault = 30000;
+
+
+/*-************************************
+*  Display Macros
+**************************************/
+#define DISPLAY(...)          fprintf(stderr, __VA_ARGS__)
+#define DISPLAYLEVEL(l, ...)  if (g_displayLevel>=l) { DISPLAY(__VA_ARGS__); }
+static U32 g_displayLevel = 2;
+
+static const U64 g_refreshRate = SEC_TO_MICRO / 6;
+static UTIL_time_t g_displayClock = UTIL_TIME_INITIALIZER;
+
+#define DISPLAYUPDATE(l, ...) \
+    if (g_displayLevel>=l) { \
+        if ((UTIL_clockSpanMicro(g_displayClock) > g_refreshRate) || (g_displayLevel>=4)) \
+        { g_displayClock = UTIL_getTime(); DISPLAY(__VA_ARGS__); \
+        if (g_displayLevel>=4) fflush(stderr); } \
+    }
+
+
+/*-*******************************************************
+*  Compile time test
+*********************************************************/
+#undef MIN
+#undef MAX
+/* Declaring the function, to avoid -Wmissing-prototype */
+void FUZ_bug976(void);
+void FUZ_bug976(void)
+{   /* these constants shall not depend on MIN() macro */
+    assert(ZSTD_HASHLOG_MAX < 31);
+    assert(ZSTD_CHAINLOG_MAX < 31);
+}
+
+
+/*-*******************************************************
+*  Internal functions
+*********************************************************/
+#define MIN(a,b) ((a)<(b)?(a):(b))
+#define MAX(a,b) ((a)>(b)?(a):(b))
+
+#define FUZ_rotl32(x,r) ((x << r) | (x >> (32 - r)))
+static U32 FUZ_rand(U32* src)
+{
+    static const U32 prime1 = 2654435761U;
+    static const U32 prime2 = 2246822519U;
+    U32 rand32 = *src;
+    rand32 *= prime1;
+    rand32 += prime2;
+    rand32  = FUZ_rotl32(rand32, 13);
+    *src = rand32;
+    return rand32 >> 5;
+}
+
+static U32 FUZ_highbit32(U32 v32)
+{
+    unsigned nbBits = 0;
+    if (v32==0) return 0;
+    while (v32) v32 >>= 1, nbBits++;
+    return nbBits;
+}
+
+
+/*=============================================
+*   Test macros
+=============================================*/
+#define CHECK_Z(f) {                               \
+    size_t const err = f;                          \
+    if (ZSTD_isError(err)) {                       \
+        DISPLAY("Error => %s : %s ",               \
+                #f, ZSTD_getErrorName(err));       \
+        exit(1);                                   \
+}   }
+
+#define CHECK_VAR(var, fn)  var = fn; if (ZSTD_isError(var)) { DISPLAYLEVEL(1, "%s : fails : %s \n", #fn, ZSTD_getErrorName(var)); goto _output_error; }
+#define CHECK_NEWV(var, fn)  size_t const CHECK_VAR(var, fn)
+#define CHECK(fn)  { CHECK_NEWV(err, fn); }
+#define CHECKPLUS(var, fn, more)  { CHECK_NEWV(var, fn); more; }
+
+#define CHECK_OP(op, lhs, rhs) {                                  \
+    if (!((lhs) op (rhs))) {                                      \
+        DISPLAY("Error L%u => FAILED %s %s %s ", __LINE__, #lhs, #op, #rhs);  \
+        goto _output_error;                                       \
+    }                                                             \
+}
+#define CHECK_EQ(lhs, rhs) CHECK_OP(==, lhs, rhs)
+#define CHECK_LT(lhs, rhs) CHECK_OP(<, lhs, rhs)
+
+
+/*=============================================
+*   Memory Tests
+=============================================*/
+#if defined(__APPLE__) && defined(__MACH__)
+
+#include <malloc/malloc.h>    /* malloc_size */
+
+typedef struct {
+    unsigned long long totalMalloc;
+    size_t currentMalloc;
+    size_t peakMalloc;
+    unsigned nbMalloc;
+    unsigned nbFree;
+} mallocCounter_t;
+
+static const mallocCounter_t INIT_MALLOC_COUNTER = { 0, 0, 0, 0, 0 };
+
+static void* FUZ_mallocDebug(void* counter, size_t size)
+{
+    mallocCounter_t* const mcPtr = (mallocCounter_t*)counter;
+    void* const ptr = malloc(size);
+    if (ptr==NULL) return NULL;
+    DISPLAYLEVEL(4, "allocating %u KB => effectively %u KB \n",
+        (unsigned)(size >> 10), (unsigned)(malloc_size(ptr) >> 10));  /* OS-X specific */
+    mcPtr->totalMalloc += size;
+    mcPtr->currentMalloc += size;
+    if (mcPtr->currentMalloc > mcPtr->peakMalloc)
+        mcPtr->peakMalloc = mcPtr->currentMalloc;
+    mcPtr->nbMalloc += 1;
+    return ptr;
+}
+
+static void FUZ_freeDebug(void* counter, void* address)
+{
+    mallocCounter_t* const mcPtr = (mallocCounter_t*)counter;
+    DISPLAYLEVEL(4, "freeing %u KB \n", (unsigned)(malloc_size(address) >> 10));
+    mcPtr->nbFree += 1;
+    mcPtr->currentMalloc -= malloc_size(address);  /* OS-X specific */
+    free(address);
+}
+
+static void FUZ_displayMallocStats(mallocCounter_t count)
+{
+    DISPLAYLEVEL(3, "peak:%6u KB,  nbMallocs:%2u, total:%6u KB \n",
+        (unsigned)(count.peakMalloc >> 10),
+        count.nbMalloc,
+        (unsigned)(count.totalMalloc >> 10));
+}
+
+static int FUZ_mallocTests_internal(unsigned seed, double compressibility, unsigned part,
+                void* inBuffer, size_t inSize, void* outBuffer, size_t outSize)
+{
+    /* test only played in verbose mode, as they are long */
+    if (g_displayLevel<3) return 0;
+
+    /* Create compressible noise */
+    if (!inBuffer || !outBuffer) {
+        DISPLAY("Not enough memory, aborting\n");
+        exit(1);
+    }
+    RDG_genBuffer(inBuffer, inSize, compressibility, 0. /*auto*/, seed);
+
+    /* simple compression tests */
+    if (part <= 1)
+    {   int compressionLevel;
+        for (compressionLevel=1; compressionLevel<=6; compressionLevel++) {
+            mallocCounter_t malcount = INIT_MALLOC_COUNTER;
+            ZSTD_customMem const cMem = { FUZ_mallocDebug, FUZ_freeDebug, &malcount };
+            ZSTD_CCtx* const cctx = ZSTD_createCCtx_advanced(cMem);
+            CHECK_Z( ZSTD_compressCCtx(cctx, outBuffer, outSize, inBuffer, inSize, compressionLevel) );
+            ZSTD_freeCCtx(cctx);
+            DISPLAYLEVEL(3, "compressCCtx level %i : ", compressionLevel);
+            FUZ_displayMallocStats(malcount);
+    }   }
+
+    /* streaming compression tests */
+    if (part <= 2)
+    {   int compressionLevel;
+        for (compressionLevel=1; compressionLevel<=6; compressionLevel++) {
+            mallocCounter_t malcount = INIT_MALLOC_COUNTER;
+            ZSTD_customMem const cMem = { FUZ_mallocDebug, FUZ_freeDebug, &malcount };
+            ZSTD_CCtx* const cstream = ZSTD_createCStream_advanced(cMem);
+            ZSTD_outBuffer out = { outBuffer, outSize, 0 };
+            ZSTD_inBuffer in = { inBuffer, inSize, 0 };
+            CHECK_Z( ZSTD_initCStream(cstream, compressionLevel) );
+            CHECK_Z( ZSTD_compressStream(cstream, &out, &in) );
+            CHECK_Z( ZSTD_endStream(cstream, &out) );
+            ZSTD_freeCStream(cstream);
+            DISPLAYLEVEL(3, "compressStream level %i : ", compressionLevel);
+            FUZ_displayMallocStats(malcount);
+    }   }
+
+    /* advanced MT API test */
+    if (part <= 3)
+    {   int nbThreads;
+        for (nbThreads=1; nbThreads<=4; nbThreads++) {
+            int compressionLevel;
+            for (compressionLevel=1; compressionLevel<=6; compressionLevel++) {
+                mallocCounter_t malcount = INIT_MALLOC_COUNTER;
+                ZSTD_customMem const cMem = { FUZ_mallocDebug, FUZ_freeDebug, &malcount };
+                ZSTD_CCtx* const cctx = ZSTD_createCCtx_advanced(cMem);
+                CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, compressionLevel) );
+                CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, nbThreads) );
+                CHECK_Z( ZSTD_compress2(cctx, outBuffer, outSize, inBuffer, inSize) );
+                ZSTD_freeCCtx(cctx);
+                DISPLAYLEVEL(3, "compress_generic,-T%i,end level %i : ",
+                                nbThreads, compressionLevel);
+                FUZ_displayMallocStats(malcount);
+    }   }   }
+
+    /* advanced MT streaming API test */
+    if (part <= 4)
+    {   int nbThreads;
+        for (nbThreads=1; nbThreads<=4; nbThreads++) {
+            int compressionLevel;
+            for (compressionLevel=1; compressionLevel<=6; compressionLevel++) {
+                mallocCounter_t malcount = INIT_MALLOC_COUNTER;
+                ZSTD_customMem const cMem = { FUZ_mallocDebug, FUZ_freeDebug, &malcount };
+                ZSTD_CCtx* const cctx = ZSTD_createCCtx_advanced(cMem);
+                ZSTD_outBuffer out = { outBuffer, outSize, 0 };
+                ZSTD_inBuffer in = { inBuffer, inSize, 0 };
+                CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, compressionLevel) );
+                CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, nbThreads) );
+                CHECK_Z( ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_continue) );
+                while ( ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end) ) {}
+                ZSTD_freeCCtx(cctx);
+                DISPLAYLEVEL(3, "compress_generic,-T%i,continue level %i : ",
+                                nbThreads, compressionLevel);
+                FUZ_displayMallocStats(malcount);
+    }   }   }
+
+    return 0;
+}
+
+static int FUZ_mallocTests(unsigned seed, double compressibility, unsigned part)
+{
+    size_t const inSize = 64 MB + 16 MB + 4 MB + 1 MB + 256 KB + 64 KB; /* 85.3 MB */
+    size_t const outSize = ZSTD_compressBound(inSize);
+    void* const inBuffer = malloc(inSize);
+    void* const outBuffer = malloc(outSize);
+    int result;
+
+    /* Create compressible noise */
+    if (!inBuffer || !outBuffer) {
+        DISPLAY("Not enough memory, aborting \n");
+        exit(1);
+    }
+
+    result = FUZ_mallocTests_internal(seed, compressibility, part,
+                    inBuffer, inSize, outBuffer, outSize);
+
+    free(inBuffer);
+    free(outBuffer);
+    return result;
+}
+
+#else
+
+static int FUZ_mallocTests(unsigned seed, double compressibility, unsigned part)
+{
+    (void)seed; (void)compressibility; (void)part;
+    return 0;
+}
+
+#endif
+
+static void FUZ_decodeSequences(BYTE* dst, ZSTD_Sequence* seqs, size_t seqsSize, BYTE* src, size_t size)
+{
+    size_t i;
+    size_t j;
+    for(i = 0; i < seqsSize - 1; ++i) {
+        assert(dst + seqs[i].litLength + seqs[i].matchLength < dst + size);
+        assert(src + seqs[i].litLength + seqs[i].matchLength < src + size);
+
+        memcpy(dst, src, seqs[i].litLength);
+        dst += seqs[i].litLength;
+        src += seqs[i].litLength;
+        size -= seqs[i].litLength;
+
+        for (j = 0; j < seqs[i].matchLength; ++j)
+            dst[j] = dst[j - seqs[i].offset];
+        dst += seqs[i].matchLength;
+        src += seqs[i].matchLength;
+        size -= seqs[i].matchLength;
+    }
+    memcpy(dst, src, size);
+}
+
+/*=============================================
+*   Unit tests
+=============================================*/
+
+static int basicUnitTests(U32 const seed, double compressibility)
+{
+    size_t const CNBuffSize = 5 MB;
+    void* const CNBuffer = malloc(CNBuffSize);
+    size_t const compressedBufferSize = ZSTD_compressBound(CNBuffSize);
+    void* const compressedBuffer = malloc(compressedBufferSize);
+    void* const decodedBuffer = malloc(CNBuffSize);
+    int testResult = 0;
+    unsigned testNb=0;
+    size_t cSize;
+
+    /* Create compressible noise */
+    if (!CNBuffer || !compressedBuffer || !decodedBuffer) {
+        DISPLAY("Not enough memory, aborting\n");
+        testResult = 1;
+        goto _end;
+    }
+    RDG_genBuffer(CNBuffer, CNBuffSize, compressibility, 0., seed);
+
+    /* Basic tests */
+    DISPLAYLEVEL(3, "test%3u : ZSTD_getErrorName : ", testNb++);
+    {   const char* errorString = ZSTD_getErrorName(0);
+        DISPLAYLEVEL(3, "OK : %s \n", errorString);
+    }
+
+    DISPLAYLEVEL(3, "test%3u : ZSTD_getErrorName with wrong value : ", testNb++);
+    {   const char* errorString = ZSTD_getErrorName(499);
+        DISPLAYLEVEL(3, "OK : %s \n", errorString);
+    }
+
+    DISPLAYLEVEL(3, "test%3u : min compression level : ", testNb++);
+    {   int const mcl = ZSTD_minCLevel();
+        DISPLAYLEVEL(3, "%i (OK) \n", mcl);
+    }
+
+    DISPLAYLEVEL(3, "test%3u : ZSTD_versionNumber : ", testNb++);
+    {   unsigned const vn = ZSTD_versionNumber();
+        DISPLAYLEVEL(3, "%u (OK) \n", vn);
+    }
+
+    DISPLAYLEVEL(3, "test%3u : compress %u bytes : ", testNb++, (unsigned)CNBuffSize);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        if (cctx==NULL) goto _output_error;
+        CHECK_VAR(cSize, ZSTD_compressCCtx(cctx,
+                            compressedBuffer, compressedBufferSize,
+                            CNBuffer, CNBuffSize, 1) );
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : size of cctx for level 1 : ", testNb++);
+        {   size_t const cctxSize = ZSTD_sizeof_CCtx(cctx);
+            DISPLAYLEVEL(3, "%u bytes \n", (unsigned)cctxSize);
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+
+    DISPLAYLEVEL(3, "test%3i : decompress skippable frame -8 size : ", testNb++);
+    {
+       char const skippable8[] = "\x50\x2a\x4d\x18\xf8\xff\xff\xff";
+       size_t const size = ZSTD_decompress(NULL, 0, skippable8, 8);
+       if (!ZSTD_isError(size)) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : ZSTD_getFrameContentSize test : ", testNb++);
+    {   unsigned long long const rSize = ZSTD_getFrameContentSize(compressedBuffer, cSize);
+        if (rSize != CNBuffSize) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : ZSTD_getDecompressedSize test : ", testNb++);
+    {   unsigned long long const rSize = ZSTD_getDecompressedSize(compressedBuffer, cSize);
+        if (rSize != CNBuffSize) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : ZSTD_findDecompressedSize test : ", testNb++);
+    {   unsigned long long const rSize = ZSTD_findDecompressedSize(compressedBuffer, cSize);
+        if (rSize != CNBuffSize) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : tight ZSTD_decompressBound test : ", testNb++);
+    {
+        unsigned long long bound = ZSTD_decompressBound(compressedBuffer, cSize);
+        if (bound != CNBuffSize) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : ZSTD_decompressBound test with invalid srcSize : ", testNb++);
+    {
+        unsigned long long bound = ZSTD_decompressBound(compressedBuffer, cSize - 1);
+        if (bound != ZSTD_CONTENTSIZE_ERROR) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : decompress %u bytes : ", testNb++, (unsigned)CNBuffSize);
+    { size_t const r = ZSTD_decompress(decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+      if (r != CNBuffSize) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : check decompressed result : ", testNb++);
+    {   size_t u;
+        for (u=0; u<CNBuffSize; u++) {
+            if (((BYTE*)decodedBuffer)[u] != ((BYTE*)CNBuffer)[u]) goto _output_error;
+    }   }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : ZSTD_checkCParams : ", testNb++);
+    {
+        ZSTD_parameters params = ZSTD_getParams(3, 0, 0);
+        assert(!ZSTD_checkCParams(params.cParams));
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : ZSTD_createDCtx_advanced and ZSTD_sizeof_DCtx: ", testNb++);
+    {
+        ZSTD_DCtx* const dctx = ZSTD_createDCtx_advanced(ZSTD_defaultCMem);
+        assert(dctx != NULL);
+        assert(ZSTD_sizeof_DCtx(dctx) != 0);
+        ZSTD_freeDCtx(dctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : misc unaccounted for zstd symbols : ", testNb++);
+    {
+        /* %p takes a void*. In ISO C, it's illegal to cast a function pointer
+         * to a data pointer. (Although in POSIX you're required to be allowed
+         * to do it...) So we have to fall back to our trusty friend memcpy. */
+        unsigned (* const funcptr_getDictID)(const ZSTD_DDict* ddict) =
+            ZSTD_getDictID_fromDDict;
+        ZSTD_DStream* (* const funcptr_createDStream)(
+            ZSTD_customMem customMem) = ZSTD_createDStream_advanced;
+        void (* const funcptr_copyDCtx)(
+            ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx) = ZSTD_copyDCtx;
+        ZSTD_nextInputType_e (* const funcptr_nextInputType)(ZSTD_DCtx* dctx) =
+            ZSTD_nextInputType;
+        const void *voidptr_getDictID;
+        const void *voidptr_createDStream;
+        const void *voidptr_copyDCtx;
+        const void *voidptr_nextInputType;
+        DEBUG_STATIC_ASSERT(sizeof(funcptr_getDictID) == sizeof(voidptr_getDictID));
+        memcpy(
+            (void*)&voidptr_getDictID,
+            (const void*)&funcptr_getDictID,
+            sizeof(void*));
+        memcpy(
+            (void*)&voidptr_createDStream,
+            (const void*)&funcptr_createDStream,
+            sizeof(void*));
+        memcpy(
+            (void*)&voidptr_copyDCtx,
+            (const void*)&funcptr_copyDCtx,
+            sizeof(void*));
+        memcpy(
+            (void*)&voidptr_nextInputType,
+            (const void*)&funcptr_nextInputType,
+            sizeof(void*));
+        DISPLAYLEVEL(3, "%p ", voidptr_getDictID);
+        DISPLAYLEVEL(3, "%p ", voidptr_createDStream);
+        DISPLAYLEVEL(3, "%p ", voidptr_copyDCtx);
+        DISPLAYLEVEL(3, "%p ", voidptr_nextInputType);
+    }
+    DISPLAYLEVEL(3, ": OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : decompress with null dict : ", testNb++);
+    {   ZSTD_DCtx* const dctx = ZSTD_createDCtx(); assert(dctx != NULL);
+        {   size_t const r = ZSTD_decompress_usingDict(dctx,
+                                                    decodedBuffer, CNBuffSize,
+                                                    compressedBuffer, cSize,
+                                                    NULL, 0);
+            if (r != CNBuffSize) goto _output_error;
+        }
+        ZSTD_freeDCtx(dctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : decompress with null DDict : ", testNb++);
+    {   ZSTD_DCtx* const dctx = ZSTD_createDCtx(); assert(dctx != NULL);
+        {   size_t const r = ZSTD_decompress_usingDDict(dctx,
+                                                    decodedBuffer, CNBuffSize,
+                                                    compressedBuffer, cSize,
+                                                    NULL);
+            if (r != CNBuffSize) goto _output_error;
+        }
+        ZSTD_freeDCtx(dctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : decompress with 1 missing byte : ", testNb++);
+    { size_t const r = ZSTD_decompress(decodedBuffer, CNBuffSize, compressedBuffer, cSize-1);
+      if (!ZSTD_isError(r)) goto _output_error;
+      if (ZSTD_getErrorCode((size_t)r) != ZSTD_error_srcSize_wrong) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : decompress with 1 too much byte : ", testNb++);
+    { size_t const r = ZSTD_decompress(decodedBuffer, CNBuffSize, compressedBuffer, cSize+1);
+      if (!ZSTD_isError(r)) goto _output_error;
+      if (ZSTD_getErrorCode(r) != ZSTD_error_srcSize_wrong) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : decompress too large input : ", testNb++);
+    { size_t const r = ZSTD_decompress(decodedBuffer, CNBuffSize, compressedBuffer, compressedBufferSize);
+      if (!ZSTD_isError(r)) goto _output_error;
+      if (ZSTD_getErrorCode(r) != ZSTD_error_srcSize_wrong) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : decompress into NULL buffer : ", testNb++);
+    { size_t const r = ZSTD_decompress(NULL, 0, compressedBuffer, compressedBufferSize);
+      if (!ZSTD_isError(r)) goto _output_error;
+      if (ZSTD_getErrorCode(r) != ZSTD_error_dstSize_tooSmall) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : ZSTD_decompressBound test with content size missing : ", testNb++);
+    {   /* create compressed buffer with content size missing */
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_contentSizeFlag, 0) );
+        CHECK_VAR(cSize, ZSTD_compress2(cctx,
+                            compressedBuffer, compressedBufferSize,
+                            CNBuffer, CNBuffSize) );
+        ZSTD_freeCCtx(cctx);
+    }
+    {   /* ensure frame content size is missing */
+        ZSTD_frameHeader zfh;
+        size_t const ret = ZSTD_getFrameHeader(&zfh, compressedBuffer, compressedBufferSize);
+        if (ret != 0 || zfh.frameContentSize !=  ZSTD_CONTENTSIZE_UNKNOWN) goto _output_error;
+    }
+    {   /* ensure CNBuffSize <= decompressBound */
+        unsigned long long const bound = ZSTD_decompressBound(compressedBuffer, compressedBufferSize);
+        if (CNBuffSize > bound) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d: check DCtx size is reduced after many oversized calls : ", testNb++);
+    {
+        size_t const largeFrameSrcSize = 200;
+        size_t const smallFrameSrcSize = 10;
+        size_t const nbFrames = 256;
+
+        size_t i = 0, consumed = 0, produced = 0, prevDCtxSize = 0;
+        int sizeReduced = 0;
+
+        BYTE* const dst = (BYTE*)compressedBuffer;
+        ZSTD_DCtx* dctx = ZSTD_createDCtx();
+
+        /* create a large frame and then a bunch of small frames */
+        size_t srcSize = ZSTD_compress((void*)dst,
+            compressedBufferSize, CNBuffer, largeFrameSrcSize, 3);
+        for (i = 0; i < nbFrames; i++)
+            srcSize += ZSTD_compress((void*)(dst + srcSize),
+                compressedBufferSize - srcSize, CNBuffer,
+                smallFrameSrcSize, 3);
+
+        /* decompressStream and make sure that dctx size was reduced at least once */
+        while (consumed < srcSize) {
+            ZSTD_inBuffer in = {(void*)(dst + consumed), MIN(1, srcSize - consumed), 0};
+            ZSTD_outBuffer out = {(BYTE*)CNBuffer + produced, CNBuffSize - produced, 0};
+            ZSTD_decompressStream(dctx, &out, &in);
+            consumed += in.pos;
+            produced += out.pos;
+
+            /* success! size was reduced from the previous frame */
+            if (prevDCtxSize > ZSTD_sizeof_DCtx(dctx))
+                sizeReduced = 1;
+
+            prevDCtxSize = ZSTD_sizeof_DCtx(dctx);
+        }
+
+        assert(sizeReduced);
+
+        ZSTD_freeDCtx(dctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : ldm fill dict out-of-bounds check", testNb++);
+    {
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+
+        size_t const size = (1U << 10);
+        size_t const dstCapacity = ZSTD_compressBound(size);
+        void* dict = (void*)malloc(size);
+        void* src = (void*)malloc(size);
+        void* dst = (void*)malloc(dstCapacity);
+
+        RDG_genBuffer(dict, size, 0.5, 0.5, seed);
+        RDG_genBuffer(src, size, 0.5, 0.5, seed);
+
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableLongDistanceMatching, 1));
+        assert(!ZSTD_isError(ZSTD_compress_usingDict(cctx, dst, dstCapacity, src, size, dict, size, 3)));
+
+        ZSTD_freeCCtx(cctx);
+        free(dict);
+        free(src);
+        free(dst);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : testing dict compression with enableLdm and forceMaxWindow : ", testNb++);
+    {
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+        void* dict = (void*)malloc(CNBuffSize);
+        int nbWorkers;
+
+        for (nbWorkers = 0; nbWorkers < 3; ++nbWorkers) {
+            RDG_genBuffer(dict, CNBuffSize, 0.5, 0.5, seed);
+            RDG_genBuffer(CNBuffer, CNBuffSize, 0.6, 0.6, seed);
+
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, nbWorkers));
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 1));
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_forceMaxWindow, 1));
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableLongDistanceMatching, 1));
+            CHECK_Z(ZSTD_CCtx_refPrefix(cctx, dict, CNBuffSize));
+            cSize = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, CNBuffSize);
+            CHECK_Z(cSize);
+            CHECK_Z(ZSTD_decompress_usingDict(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize, dict, CNBuffSize));
+        }
+
+        ZSTD_freeCCtx(cctx);
+        ZSTD_freeDCtx(dctx);
+        free(dict);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : testing ldm dictionary gets invalidated : ", testNb++);
+    {
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+        void* dict = (void*)malloc(CNBuffSize);
+        size_t const kWindowLog = 10;
+        size_t const kWindowSize = (size_t)1 << kWindowLog;
+        size_t const dictSize = kWindowSize * 10;
+        size_t const srcSize1 = kWindowSize / 2;
+        size_t const srcSize2 = kWindowSize * 10;
+
+        if (CNBuffSize < dictSize) goto _output_error;
+
+        RDG_genBuffer(dict, dictSize, 0.5, 0.5, seed);
+        RDG_genBuffer(CNBuffer, srcSize1 + srcSize2, 0.5, 0.5, seed);
+
+        /* Enable checksum to verify round trip. */
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 1));
+        /* Disable content size to skip single-pass decompression. */
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_contentSizeFlag, 0));
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_windowLog, (int)kWindowLog));
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableLongDistanceMatching, 1));
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_ldmMinMatch, 32));
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_ldmHashRateLog, 1));
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_ldmHashLog, 16));
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_ldmBucketSizeLog, 3));
+
+        /* Round trip once with a dictionary. */
+        CHECK_Z(ZSTD_CCtx_refPrefix(cctx, dict, dictSize));
+        cSize = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, srcSize1);
+        CHECK_Z(cSize);
+        CHECK_Z(ZSTD_decompress_usingDict(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize, dict, dictSize));
+        cSize = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, srcSize2);
+        /* Streaming decompression to catch out of bounds offsets. */
+        {
+            ZSTD_inBuffer in = {compressedBuffer, cSize, 0};
+            ZSTD_outBuffer out = {decodedBuffer, CNBuffSize, 0};
+            size_t const dSize = ZSTD_decompressStream(dctx, &out, &in);
+            CHECK_Z(dSize);
+            if (dSize != 0) goto _output_error;
+        }
+
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 2));
+        /* Round trip once with a dictionary. */
+        CHECK_Z(ZSTD_CCtx_refPrefix(cctx, dict, dictSize));
+        {
+            ZSTD_inBuffer in = {CNBuffer, srcSize1, 0};
+            ZSTD_outBuffer out = {compressedBuffer, compressedBufferSize, 0};
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush));
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end));
+            cSize = out.pos;
+        }
+        CHECK_Z(ZSTD_decompress_usingDict(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize, dict, dictSize));
+        {
+            ZSTD_inBuffer in = {CNBuffer, srcSize2, 0};
+            ZSTD_outBuffer out = {compressedBuffer, compressedBufferSize, 0};
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush));
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end));
+            cSize = out.pos;
+        }
+        /* Streaming decompression to catch out of bounds offsets. */
+        {
+            ZSTD_inBuffer in = {compressedBuffer, cSize, 0};
+            ZSTD_outBuffer out = {decodedBuffer, CNBuffSize, 0};
+            size_t const dSize = ZSTD_decompressStream(dctx, &out, &in);
+            CHECK_Z(dSize);
+            if (dSize != 0) goto _output_error;
+        }
+
+        ZSTD_freeCCtx(cctx);
+        ZSTD_freeDCtx(dctx);
+        free(dict);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* Note: this test takes 0.5 seconds to run */
+    DISPLAYLEVEL(3, "test%3i : testing refPrefx vs refPrefx + ldm (size comparison) : ", testNb++);
+    {
+        /* test a big buffer so that ldm can take effect */
+        size_t const size = 100 MB;
+        int const windowLog = 27;
+        size_t const dstSize = ZSTD_compressBound(size);
+
+        void* dict = (void*)malloc(size);
+        void* src = (void*)malloc(size);
+        void* dst = (void*)malloc(dstSize);
+        void* recon = (void*)malloc(size);
+
+        size_t refPrefixCompressedSize = 0;
+        size_t refPrefixLdmComrpessedSize = 0;
+        size_t reconSize = 0;
+
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+
+        /* make dict and src the same uncompressible data */
+        RDG_genBuffer(src, size, 0, 0, seed);
+        memcpy(dict, src, size);
+        assert(!memcmp(dict, src, size));
+
+        /* set level 1 and windowLog to cover src */
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 1));
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_windowLog, windowLog));
+
+        /* compress on level 1 using just refPrefix and no ldm */
+        ZSTD_CCtx_refPrefix(cctx, dict, size);
+        refPrefixCompressedSize = ZSTD_compress2(cctx, dst, dstSize, src, size);
+        assert(!ZSTD_isError(refPrefixCompressedSize));
+
+        /* test round trip just refPrefix */
+        ZSTD_DCtx_refPrefix(dctx, dict, size);
+        reconSize = ZSTD_decompressDCtx(dctx, recon, size, dst, refPrefixCompressedSize);
+        assert(!ZSTD_isError(reconSize));
+        assert(reconSize == size);
+        assert(!memcmp(recon, src, size));
+
+        /* compress on level 1 using refPrefix and ldm */
+        ZSTD_CCtx_refPrefix(cctx, dict, size);;
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableLongDistanceMatching, 1))
+        refPrefixLdmComrpessedSize = ZSTD_compress2(cctx, dst, dstSize, src, size);
+        assert(!ZSTD_isError(refPrefixLdmComrpessedSize));
+
+        /* test round trip refPrefix + ldm*/
+        ZSTD_DCtx_refPrefix(dctx, dict, size);
+        reconSize = ZSTD_decompressDCtx(dctx, recon, size, dst, refPrefixLdmComrpessedSize);
+        assert(!ZSTD_isError(reconSize));
+        assert(reconSize == size);
+        assert(!memcmp(recon, src, size));
+
+        /* make sure that refPrefixCompressedSize is significantly greater */
+        assert(refPrefixCompressedSize > 10 * refPrefixLdmComrpessedSize);
+        /* make sure the ldm comrpessed size is less than 1% of original */
+        assert((double)refPrefixLdmComrpessedSize / (double)size < 0.01);
+
+        ZSTD_freeDCtx(dctx);
+        ZSTD_freeCCtx(cctx);
+        free(recon);
+        free(dict);
+        free(src);
+        free(dst);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d: superblock uncompressible data, too many nocompress superblocks : ", testNb++);
+    {
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        const BYTE* src = (BYTE*)CNBuffer; BYTE* dst = (BYTE*)compressedBuffer;
+        size_t srcSize = 321656; size_t dstCapacity = ZSTD_compressBound(srcSize);
+
+        /* This is the number of bytes to stream before ending. This value
+         * was obtained by trial and error :/. */
+
+        const size_t streamCompressThreshold = 161792;
+        const size_t streamCompressDelta = 1024;
+
+        /* The first 1/5 of the buffer is compressible and the last 4/5 is
+         * uncompressible. This is an approximation of the type of data
+         * the fuzzer generated to catch this bug. Streams like this were making
+         * zstd generate noCompress superblocks (which are larger than the src
+         * they come from). Do this enough times, and we'll run out of room
+         * and throw a dstSize_tooSmall error. */
+
+        const size_t compressiblePartSize = srcSize/5;
+        const size_t uncompressiblePartSize = srcSize-compressiblePartSize;
+        RDG_genBuffer(CNBuffer, compressiblePartSize, 0.5, 0.5, seed);
+        RDG_genBuffer((BYTE*)CNBuffer+compressiblePartSize, uncompressiblePartSize, 0, 0, seed);
+
+        /* Setting target block size so that superblock is used */
+
+        assert(cctx != NULL);
+        ZSTD_CCtx_setParameter(cctx, ZSTD_c_targetCBlockSize, 81);
+
+        { size_t read;
+          for (read = 0; read < streamCompressThreshold; read += streamCompressDelta) {
+            ZSTD_inBuffer in = {src, streamCompressDelta, 0};
+            ZSTD_outBuffer out = {dst, dstCapacity, 0};
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_continue));
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end));
+            src += streamCompressDelta; srcSize -= streamCompressDelta;
+            dst += out.pos; dstCapacity -= out.pos;}}
+
+        /* This is trying to catch a dstSize_tooSmall error */
+
+        { ZSTD_inBuffer in = {src, srcSize, 0};
+          ZSTD_outBuffer out = {dst, dstCapacity, 0};
+          CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end));}
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d: superblock with no literals : ", testNb++);
+    /* Generate the same data 20 times over */
+    {
+        size_t const avgChunkSize = CNBuffSize / 20;
+        size_t b;
+        for (b = 0; b < CNBuffSize; b += avgChunkSize) {
+            size_t const chunkSize = MIN(CNBuffSize - b, avgChunkSize);
+            RDG_genBuffer((char*)CNBuffer + b, chunkSize, compressibility, 0. /* auto */, seed);
+        }
+    }
+    {
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        size_t const normalCSize = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, CNBuffSize);
+        size_t const allowedExpansion = (CNBuffSize * 3 / 1000);
+        size_t superCSize;
+        CHECK_Z(normalCSize);
+        ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 19);
+        ZSTD_CCtx_setParameter(cctx, ZSTD_c_targetCBlockSize, 1000);
+        superCSize = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, CNBuffSize);
+        CHECK_Z(superCSize);
+        if (superCSize > normalCSize + allowedExpansion) {
+            DISPLAYLEVEL(1, "Superblock too big: %u > %u + %u \n", (U32)superCSize, (U32)normalCSize, (U32)allowedExpansion);
+            goto _output_error;
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    RDG_genBuffer(CNBuffer, CNBuffSize, compressibility, 0. /*auto*/, seed);
+    DISPLAYLEVEL(3, "test%3d: superblock enough room for checksum : ", testNb++)
+    {
+        /* This tests whether or not we leave enough room for the checksum at the end
+         * of the dst buffer. The bug that motivated this test was found by the
+         * stream_round_trip fuzzer but this crashes for the same reason and is
+         * far more compact than re-creating the stream_round_trip fuzzer's code path */
+        ZSTD_CCtx *cctx = ZSTD_createCCtx();
+        ZSTD_CCtx_setParameter(cctx, ZSTD_c_targetCBlockSize, 64);
+        assert(!ZSTD_isError(ZSTD_compress2(cctx, compressedBuffer, 1339, CNBuffer, 1278)));
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : compress a NULL input with each level : ", testNb++);
+    {   int level = -1;
+        ZSTD_CCtx* cctx = ZSTD_createCCtx();
+        if (!cctx) goto _output_error;
+        for (level = -1; level <= ZSTD_maxCLevel(); ++level) {
+          CHECK_Z( ZSTD_compress(compressedBuffer, compressedBufferSize, NULL, 0, level) );
+          CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, level) );
+          CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, NULL, 0) );
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d : check CCtx size after compressing empty input : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        size_t const r = ZSTD_compressCCtx(cctx, compressedBuffer, compressedBufferSize, NULL, 0, 19);
+        if (ZSTD_isError(r)) goto _output_error;
+        if (ZSTD_sizeof_CCtx(cctx) > (1U << 20)) goto _output_error;
+        ZSTD_freeCCtx(cctx);
+        cSize = r;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d : decompress empty frame into NULL : ", testNb++);
+    {   size_t const r = ZSTD_decompress(NULL, 0, compressedBuffer, cSize);
+        if (ZSTD_isError(r)) goto _output_error;
+        if (r != 0) goto _output_error;
+    }
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_outBuffer output;
+        if (cctx==NULL) goto _output_error;
+        output.dst = compressedBuffer;
+        output.size = compressedBufferSize;
+        output.pos = 0;
+        CHECK_Z( ZSTD_initCStream(cctx, 1) );    /* content size unknown */
+        CHECK_Z( ZSTD_flushStream(cctx, &output) );   /* ensure no possibility to "concatenate" and determine the content size */
+        CHECK_Z( ZSTD_endStream(cctx, &output) );
+        ZSTD_freeCCtx(cctx);
+        /* single scan decompression */
+        {   size_t const r = ZSTD_decompress(NULL, 0, compressedBuffer, output.pos);
+            if (ZSTD_isError(r)) goto _output_error;
+            if (r != 0) goto _output_error;
+        }
+        /* streaming decompression */
+        {   ZSTD_DCtx* const dstream = ZSTD_createDStream();
+            ZSTD_inBuffer dinput;
+            ZSTD_outBuffer doutput;
+            size_t ipos;
+            if (dstream==NULL) goto _output_error;
+            dinput.src = compressedBuffer;
+            dinput.size = 0;
+            dinput.pos = 0;
+            doutput.dst = NULL;
+            doutput.size = 0;
+            doutput.pos = 0;
+            CHECK_Z ( ZSTD_initDStream(dstream) );
+            for (ipos=1; ipos<=output.pos; ipos++) {
+                dinput.size = ipos;
+                CHECK_Z ( ZSTD_decompressStream(dstream, &doutput, &dinput) );
+            }
+            if (doutput.pos != 0) goto _output_error;
+            ZSTD_freeDStream(dstream);
+        }
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d : re-use CCtx with expanding block size : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_parameters const params = ZSTD_getParams(1, ZSTD_CONTENTSIZE_UNKNOWN, 0);
+        assert(params.fParams.contentSizeFlag == 1);  /* block size will be adapted if pledgedSrcSize is enabled */
+        CHECK_Z( ZSTD_compressBegin_advanced(cctx, NULL, 0, params, 1 /*pledgedSrcSize*/) );
+        CHECK_Z( ZSTD_compressEnd(cctx, compressedBuffer, compressedBufferSize, CNBuffer, 1) ); /* creates a block size of 1 */
+
+        CHECK_Z( ZSTD_compressBegin_advanced(cctx, NULL, 0, params, ZSTD_CONTENTSIZE_UNKNOWN) );  /* re-use same parameters */
+        {   size_t const inSize = 2* 128 KB;
+            size_t const outSize = ZSTD_compressBound(inSize);
+            CHECK_Z( ZSTD_compressEnd(cctx, compressedBuffer, outSize, CNBuffer, inSize) );
+            /* will fail if blockSize is not resized */
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d : re-using a CCtx should compress the same : ", testNb++);
+    {   size_t const sampleSize = 30;
+        int i;
+        for (i=0; i<20; i++)
+            ((char*)CNBuffer)[i] = (char)i;   /* ensure no match during initial section */
+        memcpy((char*)CNBuffer + 20, CNBuffer, 10);   /* create one match, starting from beginning of sample, which is the difficult case (see #1241) */
+        for (i=1; i<=19; i++) {
+            ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+            size_t size1, size2;
+            DISPLAYLEVEL(5, "l%i ", i);
+            size1 = ZSTD_compressCCtx(cctx, compressedBuffer, compressedBufferSize, CNBuffer, sampleSize, i);
+            CHECK_Z(size1);
+
+            size2 = ZSTD_compressCCtx(cctx, compressedBuffer, compressedBufferSize, CNBuffer, sampleSize, i);
+            CHECK_Z(size2);
+            CHECK_EQ(size1, size2);
+
+            CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, i) );
+            size2 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, sampleSize);
+            CHECK_Z(size2);
+            CHECK_EQ(size1, size2);
+
+            size2 = ZSTD_compress2(cctx, compressedBuffer, ZSTD_compressBound(sampleSize) - 1, CNBuffer, sampleSize);  /* force streaming, as output buffer is not large enough to guarantee success */
+            CHECK_Z(size2);
+            CHECK_EQ(size1, size2);
+
+            {   ZSTD_inBuffer inb;
+                ZSTD_outBuffer outb;
+                inb.src = CNBuffer;
+                inb.pos = 0;
+                inb.size = sampleSize;
+                outb.dst = compressedBuffer;
+                outb.pos = 0;
+                outb.size = ZSTD_compressBound(sampleSize) - 1;  /* force streaming, as output buffer is not large enough to guarantee success */
+                CHECK_Z( ZSTD_compressStream2(cctx, &outb, &inb, ZSTD_e_end) );
+                assert(inb.pos == inb.size);
+                CHECK_EQ(size1, outb.pos);
+            }
+
+            ZSTD_freeCCtx(cctx);
+        }
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d : btultra2 & 1st block : ", testNb++);
+    {   size_t const sampleSize = 1024;
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_inBuffer inb;
+        ZSTD_outBuffer outb;
+        inb.src = CNBuffer;
+        inb.pos = 0;
+        inb.size = 0;
+        outb.dst = compressedBuffer;
+        outb.pos = 0;
+        outb.size = compressedBufferSize;
+        CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, ZSTD_maxCLevel()) );
+
+        inb.size = sampleSize;   /* start with something, so that context is already used */
+        CHECK_Z( ZSTD_compressStream2(cctx, &outb, &inb, ZSTD_e_end) );   /* will break internal assert if stats_init is not disabled */
+        assert(inb.pos == inb.size);
+        outb.pos = 0;     /* cancel output */
+
+        CHECK_Z( ZSTD_CCtx_setPledgedSrcSize(cctx, sampleSize) );
+        inb.size = 4;   /* too small size : compression will be skipped */
+        inb.pos = 0;
+        CHECK_Z( ZSTD_compressStream2(cctx, &outb, &inb, ZSTD_e_flush) );
+        assert(inb.pos == inb.size);
+
+        inb.size += 5;   /* too small size : compression will be skipped */
+        CHECK_Z( ZSTD_compressStream2(cctx, &outb, &inb, ZSTD_e_flush) );
+        assert(inb.pos == inb.size);
+
+        inb.size += 11;   /* small enough to attempt compression */
+        CHECK_Z( ZSTD_compressStream2(cctx, &outb, &inb, ZSTD_e_flush) );
+        assert(inb.pos == inb.size);
+
+        assert(inb.pos < sampleSize);
+        inb.size = sampleSize;   /* large enough to trigger stats_init, but no longer at beginning */
+        CHECK_Z( ZSTD_compressStream2(cctx, &outb, &inb, ZSTD_e_end) );   /* will break internal assert if stats_init is not disabled */
+        assert(inb.pos == inb.size);
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d : ZSTD_CCtx_getParameter() : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_outBuffer out = {NULL, 0, 0};
+        ZSTD_inBuffer in = {NULL, 0, 0};
+        int value;
+
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_compressionLevel, &value));
+        CHECK_EQ(value, 3);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_hashLog, &value));
+        CHECK_EQ(value, 0);
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_hashLog, ZSTD_HASHLOG_MIN));
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_compressionLevel, &value));
+        CHECK_EQ(value, 3);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_hashLog, &value));
+        CHECK_EQ(value, ZSTD_HASHLOG_MIN);
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 7));
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_compressionLevel, &value));
+        CHECK_EQ(value, 7);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_hashLog, &value));
+        CHECK_EQ(value, ZSTD_HASHLOG_MIN);
+        /* Start a compression job */
+        ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_continue);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_compressionLevel, &value));
+        CHECK_EQ(value, 7);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_hashLog, &value));
+        CHECK_EQ(value, ZSTD_HASHLOG_MIN);
+        /* Reset the CCtx */
+        ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_compressionLevel, &value));
+        CHECK_EQ(value, 7);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_hashLog, &value));
+        CHECK_EQ(value, ZSTD_HASHLOG_MIN);
+        /* Reset the parameters */
+        ZSTD_CCtx_reset(cctx, ZSTD_reset_parameters);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_compressionLevel, &value));
+        CHECK_EQ(value, 3);
+        CHECK_Z(ZSTD_CCtx_getParameter(cctx, ZSTD_c_hashLog, &value));
+        CHECK_EQ(value, 0);
+
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* this test is really too long, and should be made faster */
+    DISPLAYLEVEL(3, "test%3d : overflow protection with large windowLog : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_parameters params = ZSTD_getParams(-999, ZSTD_CONTENTSIZE_UNKNOWN, 0);
+        size_t const nbCompressions = ((1U << 31) / CNBuffSize) + 2;   /* ensure U32 overflow protection is triggered */
+        size_t cnb;
+        assert(cctx != NULL);
+        params.fParams.contentSizeFlag = 0;
+        params.cParams.windowLog = ZSTD_WINDOWLOG_MAX;
+        for (cnb = 0; cnb < nbCompressions; ++cnb) {
+            DISPLAYLEVEL(6, "run %zu / %zu \n", cnb, nbCompressions);
+            CHECK_Z( ZSTD_compressBegin_advanced(cctx, NULL, 0, params, ZSTD_CONTENTSIZE_UNKNOWN) );  /* re-use same parameters */
+            CHECK_Z( ZSTD_compressEnd(cctx, compressedBuffer, compressedBufferSize, CNBuffer, CNBuffSize) );
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3d : size down context : ", testNb++);
+    {   ZSTD_CCtx* const largeCCtx = ZSTD_createCCtx();
+        assert(largeCCtx != NULL);
+        CHECK_Z( ZSTD_compressBegin(largeCCtx, 19) );   /* streaming implies ZSTD_CONTENTSIZE_UNKNOWN, which maximizes memory usage */
+        CHECK_Z( ZSTD_compressEnd(largeCCtx, compressedBuffer, compressedBufferSize, CNBuffer, 1) );
+        {   size_t const largeCCtxSize = ZSTD_sizeof_CCtx(largeCCtx);   /* size of context must be measured after compression */
+            {   ZSTD_CCtx* const smallCCtx = ZSTD_createCCtx();
+                assert(smallCCtx != NULL);
+                CHECK_Z(ZSTD_compressCCtx(smallCCtx, compressedBuffer, compressedBufferSize, CNBuffer, 1, 1));
+                {   size_t const smallCCtxSize = ZSTD_sizeof_CCtx(smallCCtx);
+                    DISPLAYLEVEL(5, "(large) %zuKB > 32*%zuKB (small) : ",
+                                largeCCtxSize>>10, smallCCtxSize>>10);
+                    assert(largeCCtxSize > 32* smallCCtxSize);  /* note : "too large" definition is handled within zstd_compress.c .
+                                                                 * make this test case extreme, so that it doesn't depend on a possibly fluctuating definition */
+                }
+                ZSTD_freeCCtx(smallCCtx);
+            }
+            {   U32 const maxNbAttempts = 1100;   /* nb of usages before triggering size down is handled within zstd_compress.c.
+                                                   * currently defined as 128x, but could be adjusted in the future.
+                                                   * make this test long enough so that it's not too much tied to the current definition within zstd_compress.c */
+                unsigned u;
+                for (u=0; u<maxNbAttempts; u++) {
+                    CHECK_Z(ZSTD_compressCCtx(largeCCtx, compressedBuffer, compressedBufferSize, CNBuffer, 1, 1));
+                    if (ZSTD_sizeof_CCtx(largeCCtx) < largeCCtxSize) break;   /* sized down */
+                }
+                DISPLAYLEVEL(5, "size down after %u attempts : ", u);
+                if (u==maxNbAttempts) goto _output_error;   /* no sizedown happened */
+            }
+        }
+        ZSTD_freeCCtx(largeCCtx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* Static CCtx tests */
+#define STATIC_CCTX_LEVEL 4
+    DISPLAYLEVEL(3, "test%3i : create static CCtx for level %u : ", testNb++, STATIC_CCTX_LEVEL);
+    {   size_t const staticCStreamSize = ZSTD_estimateCStreamSize(STATIC_CCTX_LEVEL);
+        void* const staticCCtxBuffer = malloc(staticCStreamSize);
+        size_t const staticDCtxSize = ZSTD_estimateDCtxSize();
+        void* const staticDCtxBuffer = malloc(staticDCtxSize);
+        DISPLAYLEVEL(4, "CStream size = %u, ", (U32)staticCStreamSize);
+        if (staticCCtxBuffer==NULL || staticDCtxBuffer==NULL) {
+            free(staticCCtxBuffer);
+            free(staticDCtxBuffer);
+            DISPLAY("Not enough memory, aborting\n");
+            testResult = 1;
+            goto _end;
+        }
+        {   size_t const smallInSize = 32 KB;
+            ZSTD_compressionParameters const cparams_small = ZSTD_getCParams(STATIC_CCTX_LEVEL, smallInSize, 0);
+            size_t const smallCCtxSize = ZSTD_estimateCCtxSize_usingCParams(cparams_small);
+            size_t const staticCCtxSize = ZSTD_estimateCCtxSize(STATIC_CCTX_LEVEL);
+            ZSTD_CCtx* staticCCtx = ZSTD_initStaticCCtx(staticCCtxBuffer, smallCCtxSize);
+            ZSTD_DCtx* const staticDCtx = ZSTD_initStaticDCtx(staticDCtxBuffer, staticDCtxSize);
+            DISPLAYLEVEL(4, "Full CCtx size = %u, ", (U32)staticCCtxSize);
+            DISPLAYLEVEL(4, "CCtx for 32 KB = %u, ", (U32)smallCCtxSize);
+            if ((staticCCtx==NULL) || (staticDCtx==NULL)) goto _output_error;
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : compress small input with small static CCtx : ", testNb++);
+            CHECK_VAR(cSize, ZSTD_compressCCtx(staticCCtx,
+                                  compressedBuffer, compressedBufferSize,
+                                  CNBuffer, smallInSize, STATIC_CCTX_LEVEL) );
+            DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n",
+                            (unsigned)cSize, (double)cSize/smallInSize*100);
+
+            DISPLAYLEVEL(3, "test%3i : compress large input with small static CCtx (must fail) : ", testNb++);
+            {   size_t const r = ZSTD_compressCCtx(staticCCtx,
+                                  compressedBuffer, compressedBufferSize,
+                                  CNBuffer, CNBuffSize, STATIC_CCTX_LEVEL);
+                if (ZSTD_getErrorCode((size_t)r) != ZSTD_error_memory_allocation) goto _output_error;
+            }
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : resize context to full CCtx size : ", testNb++);
+            staticCCtx = ZSTD_initStaticCStream(staticCCtxBuffer, staticCCtxSize);
+            DISPLAYLEVEL(4, "staticCCtxBuffer = %p,  staticCCtx = %p , ", staticCCtxBuffer, staticCCtx);
+            if (staticCCtx == NULL) goto _output_error;
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : compress large input with static CCtx : ", testNb++);
+            CHECK_VAR(cSize, ZSTD_compressCCtx(staticCCtx,
+                                  compressedBuffer, compressedBufferSize,
+                                  CNBuffer, CNBuffSize, STATIC_CCTX_LEVEL) );
+            DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n",
+                            (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+            DISPLAYLEVEL(3, "test%3i : compress small input often enough to trigger context reduce : ", testNb++);
+            {   int nbc;
+                assert(staticCCtxSize > smallCCtxSize * ZSTD_WORKSPACETOOLARGE_FACTOR);  /* ensure size down scenario */
+                assert(CNBuffSize > smallInSize + ZSTD_WORKSPACETOOLARGE_MAXDURATION + 3);
+                for (nbc=0; nbc<ZSTD_WORKSPACETOOLARGE_MAXDURATION+2; nbc++) {
+                    CHECK_Z(ZSTD_compressCCtx(staticCCtx,
+                                  compressedBuffer, compressedBufferSize,
+                                  (char*)CNBuffer + nbc, smallInSize,
+                                  STATIC_CCTX_LEVEL) );
+            }   }
+            DISPLAYLEVEL(3, "OK \n")
+
+            DISPLAYLEVEL(3, "test%3i : init CCtx for level %u : ", testNb++, STATIC_CCTX_LEVEL);
+            CHECK_Z( ZSTD_compressBegin(staticCCtx, STATIC_CCTX_LEVEL) );
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : compression again with static CCtx : ", testNb++);
+            CHECK_VAR(cSize, ZSTD_compressCCtx(staticCCtx,
+                                  compressedBuffer, compressedBufferSize,
+                                  CNBuffer, CNBuffSize, STATIC_CCTX_LEVEL) );
+            DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n",
+                            (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+            DISPLAYLEVEL(3, "test%3i : simple decompression test with static DCtx : ", testNb++);
+            { size_t const r = ZSTD_decompressDCtx(staticDCtx,
+                                                decodedBuffer, CNBuffSize,
+                                                compressedBuffer, cSize);
+              if (r != CNBuffSize) goto _output_error; }
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : check decompressed result : ", testNb++);
+            if (memcmp(decodedBuffer, CNBuffer, CNBuffSize)) goto _output_error;
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : init CCtx for too large level (must fail) : ", testNb++);
+            { size_t const r = ZSTD_compressBegin(staticCCtx, ZSTD_maxCLevel());
+              if (!ZSTD_isError(r)) goto _output_error; }
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : init CCtx for small level %u (should work again) : ", testNb++, 1);
+            CHECK( ZSTD_compressBegin(staticCCtx, 1) );
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : use CStream on CCtx-sized static context (should fail) : ", testNb++);
+            CHECK_Z( ZSTD_initCStream(staticCCtx, STATIC_CCTX_LEVEL) ); /* note : doesn't allocate */
+            {   ZSTD_outBuffer output = { compressedBuffer, compressedBufferSize, 0 };
+                ZSTD_inBuffer input = { CNBuffer, CNBuffSize, 0 };
+                size_t const r = ZSTD_compressStream(staticCCtx, &output, &input); /* now allocates, should fail */
+                if (!ZSTD_isError(r)) goto _output_error;
+            }
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : resize context to CStream size, then stream compress : ", testNb++);
+            staticCCtx = ZSTD_initStaticCStream(staticCCtxBuffer, staticCStreamSize);
+            assert(staticCCtx != NULL);
+            CHECK_Z( ZSTD_initCStream(staticCCtx, STATIC_CCTX_LEVEL) ); /* note : doesn't allocate */
+            {   ZSTD_outBuffer output = { compressedBuffer, compressedBufferSize, 0 };
+                ZSTD_inBuffer input = { CNBuffer, CNBuffSize, 0 };
+                CHECK_Z( ZSTD_compressStream(staticCCtx, &output, &input) );
+            }
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : CStream for small level %u : ", testNb++, 1);
+            CHECK_Z( ZSTD_initCStream(staticCCtx, 1) ); /* note : doesn't allocate */
+            {   ZSTD_outBuffer output = { compressedBuffer, compressedBufferSize, 0 };
+                ZSTD_inBuffer input = { CNBuffer, CNBuffSize, 0 };
+                CHECK_Z( ZSTD_compressStream(staticCCtx, &output, &input) );
+            }
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : init static CStream with dictionary (should fail) : ", testNb++);
+            { size_t const r = ZSTD_initCStream_usingDict(staticCCtx, CNBuffer, 64 KB, 1);
+              if (!ZSTD_isError(r)) goto _output_error; }
+            DISPLAYLEVEL(3, "OK \n");
+
+            DISPLAYLEVEL(3, "test%3i : use DStream on DCtx-sized static context (should fail) : ", testNb++);
+            CHECK_Z( ZSTD_initDStream(staticDCtx) );
+            {   ZSTD_outBuffer output = { decodedBuffer, CNBuffSize, 0 };
+                ZSTD_inBuffer input = { compressedBuffer, ZSTD_FRAMEHEADERSIZE_MAX+1, 0 };
+                size_t const r = ZSTD_decompressStream(staticDCtx, &output, &input);
+                if (!ZSTD_isError(r)) goto _output_error;
+            }
+            DISPLAYLEVEL(3, "OK \n");
+        }
+        free(staticCCtxBuffer);
+        free(staticDCtxBuffer);
+    }
+
+    DISPLAYLEVEL(3, "test%3i : Static context sizes for negative levels : ", testNb++);
+    {   size_t const cctxSizeN1 = ZSTD_estimateCCtxSize(-1);
+        size_t const cctxSizeP1 = ZSTD_estimateCCtxSize(1);
+        size_t const cstreamSizeN1 = ZSTD_estimateCStreamSize(-1);
+        size_t const cstreamSizeP1 = ZSTD_estimateCStreamSize(1);
+
+        if (!(0 < cctxSizeN1 && cctxSizeN1 <= cctxSizeP1)) goto _output_error;
+        if (!(0 < cstreamSizeN1 && cstreamSizeN1 <= cstreamSizeP1)) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+
+    /* ZSTDMT simple MT compression test */
+    DISPLAYLEVEL(3, "test%3i : create ZSTDMT CCtx : ", testNb++);
+    {   ZSTDMT_CCtx* const mtctx = ZSTDMT_createCCtx(2);
+        if (mtctx==NULL) {
+            DISPLAY("mtctx : not enough memory, aborting \n");
+            testResult = 1;
+            goto _end;
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3u : compress %u bytes with 2 threads : ", testNb++, (unsigned)CNBuffSize);
+        CHECK_VAR(cSize, ZSTDMT_compressCCtx(mtctx,
+                                compressedBuffer, compressedBufferSize,
+                                CNBuffer, CNBuffSize,
+                                1) );
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : decompressed size test : ", testNb++);
+        {   unsigned long long const rSize = ZSTD_getFrameContentSize(compressedBuffer, cSize);
+            if (rSize != CNBuffSize)  {
+                DISPLAY("ZSTD_getFrameContentSize incorrect : %u != %u \n", (unsigned)rSize, (unsigned)CNBuffSize);
+                goto _output_error;
+        }   }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : decompress %u bytes : ", testNb++, (unsigned)CNBuffSize);
+        { size_t const r = ZSTD_decompress(decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+          if (r != CNBuffSize) goto _output_error; }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : check decompressed result : ", testNb++);
+        {   size_t u;
+            for (u=0; u<CNBuffSize; u++) {
+                if (((BYTE*)decodedBuffer)[u] != ((BYTE*)CNBuffer)[u]) goto _output_error;
+        }   }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : compress -T2 with checksum : ", testNb++);
+        {   ZSTD_parameters params = ZSTD_getParams(1, CNBuffSize, 0);
+            params.fParams.checksumFlag = 1;
+            params.fParams.contentSizeFlag = 1;
+            CHECK_VAR(cSize, ZSTDMT_compress_advanced(mtctx,
+                                    compressedBuffer, compressedBufferSize,
+                                    CNBuffer, CNBuffSize,
+                                    NULL, params, 3 /*overlapRLog*/) );
+        }
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : decompress %u bytes : ", testNb++, (unsigned)CNBuffSize);
+        { size_t const r = ZSTD_decompress(decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+          if (r != CNBuffSize) goto _output_error; }
+        DISPLAYLEVEL(3, "OK \n");
+
+        ZSTDMT_freeCCtx(mtctx);
+    }
+
+    DISPLAYLEVEL(3, "test%3u : compress empty string and decompress with small window log : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+        char out[32];
+        if (cctx == NULL || dctx == NULL) goto _output_error;
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_contentSizeFlag, 0) );
+        CHECK_VAR(cSize, ZSTD_compress2(cctx, out, sizeof(out), NULL, 0) );
+        DISPLAYLEVEL(3, "OK (%u bytes)\n", (unsigned)cSize);
+
+        CHECK( ZSTD_DCtx_setParameter(dctx, ZSTD_d_windowLogMax, 10) );
+        {   char const* outPtr = out;
+            ZSTD_inBuffer inBuffer = { outPtr, cSize, 0 };
+            ZSTD_outBuffer outBuffer = { NULL, 0, 0 };
+            size_t dSize;
+            CHECK_VAR(dSize, ZSTD_decompressStream(dctx, &outBuffer, &inBuffer) );
+            if (dSize != 0) goto _output_error;
+        }
+
+        ZSTD_freeDCtx(dctx);
+        ZSTD_freeCCtx(cctx);
+    }
+
+    DISPLAYLEVEL(3, "test%3i : compress -T2 with/without literals compression : ", testNb++)
+    {   ZSTD_CCtx* cctx = ZSTD_createCCtx();
+        size_t cSize1, cSize2;
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 1) );
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 2) );
+        cSize1 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, CNBuffSize);
+        CHECK(cSize1);
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_literalCompressionMode, ZSTD_lcm_uncompressed) );
+        cSize2 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, CNBuffSize);
+        CHECK(cSize2);
+        CHECK_LT(cSize1, cSize2);
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : Multithreaded ZSTD_compress2() with rsyncable : ", testNb++)
+    {   ZSTD_CCtx* cctx = ZSTD_createCCtx();
+        /* Set rsyncable and don't give the ZSTD_compressBound(CNBuffSize) so
+         * ZSTDMT is forced to not take the shortcut.
+         */
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 1) );
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 1) );
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_rsyncable, 1) );
+        CHECK( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize - 1, CNBuffer, CNBuffSize) );
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : setting multithreaded parameters : ", testNb++)
+    {   ZSTD_CCtx_params* params = ZSTD_createCCtxParams();
+        int value;
+        /* Check that the overlap log and job size are unset. */
+        CHECK( ZSTD_CCtxParams_getParameter(params, ZSTD_c_overlapLog, &value) );
+        CHECK_EQ(value, 0);
+        CHECK( ZSTD_CCtxParams_getParameter(params, ZSTD_c_jobSize, &value) );
+        CHECK_EQ(value, 0);
+        /* Set and check the overlap log and job size. */
+        CHECK( ZSTD_CCtxParams_setParameter(params, ZSTD_c_overlapLog, 5) );
+        CHECK( ZSTD_CCtxParams_setParameter(params, ZSTD_c_jobSize, 2 MB) );
+        CHECK( ZSTD_CCtxParams_getParameter(params, ZSTD_c_overlapLog, &value) );
+        CHECK_EQ(value, 5);
+        CHECK( ZSTD_CCtxParams_getParameter(params, ZSTD_c_jobSize, &value) );
+        CHECK_EQ(value, 2 MB);
+        /* Set the number of workers and check the overlap log and job size. */
+        CHECK( ZSTD_CCtxParams_setParameter(params, ZSTD_c_nbWorkers, 2) );
+        CHECK( ZSTD_CCtxParams_getParameter(params, ZSTD_c_overlapLog, &value) );
+        CHECK_EQ(value, 5);
+        CHECK( ZSTD_CCtxParams_getParameter(params, ZSTD_c_jobSize, &value) );
+        CHECK_EQ(value, 2 MB);
+        ZSTD_freeCCtxParams(params);
+
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* Simple API multiframe test */
+    DISPLAYLEVEL(3, "test%3i : compress multiple frames : ", testNb++);
+    {   size_t off = 0;
+        int i;
+        int const segs = 4;
+        /* only use the first half so we don't push against size limit of compressedBuffer */
+        size_t const segSize = (CNBuffSize / 2) / segs;
+        for (i = 0; i < segs; i++) {
+            CHECK_NEWV(r, ZSTD_compress(
+                            (BYTE*)compressedBuffer + off, CNBuffSize - off,
+                            (BYTE*)CNBuffer + segSize * (size_t)i, segSize,
+                            5) );
+            off += r;
+            if (i == segs/2) {
+                /* insert skippable frame */
+                const U32 skipLen = 129 KB;
+                MEM_writeLE32((BYTE*)compressedBuffer + off, ZSTD_MAGIC_SKIPPABLE_START);
+                MEM_writeLE32((BYTE*)compressedBuffer + off + 4, skipLen);
+                off += skipLen + ZSTD_SKIPPABLEHEADERSIZE;
+            }
+        }
+        cSize = off;
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : get decompressed size of multiple frames : ", testNb++);
+    {   unsigned long long const r = ZSTD_findDecompressedSize(compressedBuffer, cSize);
+        if (r != CNBuffSize / 2) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : get tight decompressed bound of multiple frames : ", testNb++);
+    {   unsigned long long const bound = ZSTD_decompressBound(compressedBuffer, cSize);
+        if (bound != CNBuffSize / 2) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : decompress multiple frames : ", testNb++);
+    {   CHECK_NEWV(r, ZSTD_decompress(decodedBuffer, CNBuffSize, compressedBuffer, cSize));
+        if (r != CNBuffSize / 2) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : check decompressed result : ", testNb++);
+    if (memcmp(decodedBuffer, CNBuffer, CNBuffSize / 2) != 0) goto _output_error;
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* Dictionary and CCtx Duplication tests */
+    {   ZSTD_CCtx* const ctxOrig = ZSTD_createCCtx();
+        ZSTD_CCtx* const ctxDuplicated = ZSTD_createCCtx();
+        ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+        static const size_t dictSize = 551;
+        assert(dctx != NULL); assert(ctxOrig != NULL); assert(ctxDuplicated != NULL);
+
+        DISPLAYLEVEL(3, "test%3i : copy context too soon : ", testNb++);
+        { size_t const copyResult = ZSTD_copyCCtx(ctxDuplicated, ctxOrig, 0);
+          if (!ZSTD_isError(copyResult)) goto _output_error; }   /* error must be detected */
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : load dictionary into context : ", testNb++);
+        CHECK( ZSTD_compressBegin_usingDict(ctxOrig, CNBuffer, dictSize, 2) );
+        CHECK( ZSTD_copyCCtx(ctxDuplicated, ctxOrig, 0) ); /* Begin_usingDict implies unknown srcSize, so match that */
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : compress with flat dictionary : ", testNb++);
+        cSize = 0;
+        CHECKPLUS(r, ZSTD_compressEnd(ctxOrig,
+                                      compressedBuffer, compressedBufferSize,
+                         (const char*)CNBuffer + dictSize, CNBuffSize - dictSize),
+                  cSize += r);
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : frame built with flat dictionary should be decompressible : ", testNb++);
+        CHECKPLUS(r, ZSTD_decompress_usingDict(dctx,
+                                       decodedBuffer, CNBuffSize,
+                                       compressedBuffer, cSize,
+                                       CNBuffer, dictSize),
+                  if (r != CNBuffSize - dictSize) goto _output_error);
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : compress with duplicated context : ", testNb++);
+        {   size_t const cSizeOrig = cSize;
+            cSize = 0;
+            CHECKPLUS(r, ZSTD_compressEnd(ctxDuplicated,
+                                    compressedBuffer, compressedBufferSize,
+                       (const char*)CNBuffer + dictSize, CNBuffSize - dictSize),
+                      cSize += r);
+            if (cSize != cSizeOrig) goto _output_error;   /* should be identical ==> same size */
+        }
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : frame built with duplicated context should be decompressible : ", testNb++);
+        CHECKPLUS(r, ZSTD_decompress_usingDict(dctx,
+                                           decodedBuffer, CNBuffSize,
+                                           compressedBuffer, cSize,
+                                           CNBuffer, dictSize),
+                  if (r != CNBuffSize - dictSize) goto _output_error);
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : decompress with DDict : ", testNb++);
+        {   ZSTD_DDict* const ddict = ZSTD_createDDict(CNBuffer, dictSize);
+            size_t const r = ZSTD_decompress_usingDDict(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize, ddict);
+            if (r != CNBuffSize - dictSize) goto _output_error;
+            DISPLAYLEVEL(3, "OK (size of DDict : %u) \n", (unsigned)ZSTD_sizeof_DDict(ddict));
+            ZSTD_freeDDict(ddict);
+        }
+
+        DISPLAYLEVEL(3, "test%3i : decompress with static DDict : ", testNb++);
+        {   size_t const ddictBufferSize = ZSTD_estimateDDictSize(dictSize, ZSTD_dlm_byCopy);
+            void* const ddictBuffer = malloc(ddictBufferSize);
+            if (ddictBuffer == NULL) goto _output_error;
+            {   const ZSTD_DDict* const ddict = ZSTD_initStaticDDict(ddictBuffer, ddictBufferSize, CNBuffer, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
+                size_t const r = ZSTD_decompress_usingDDict(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize, ddict);
+                if (r != CNBuffSize - dictSize) goto _output_error;
+            }
+            free(ddictBuffer);
+            DISPLAYLEVEL(3, "OK (size of static DDict : %u) \n", (unsigned)ddictBufferSize);
+        }
+
+        DISPLAYLEVEL(3, "test%3i : check content size on duplicated context : ", testNb++);
+        {   size_t const testSize = CNBuffSize / 3;
+            {   ZSTD_parameters p = ZSTD_getParams(2, testSize, dictSize);
+                p.fParams.contentSizeFlag = 1;
+                CHECK( ZSTD_compressBegin_advanced(ctxOrig, CNBuffer, dictSize, p, testSize-1) );
+            }
+            CHECK( ZSTD_copyCCtx(ctxDuplicated, ctxOrig, testSize) );
+
+            CHECK_VAR(cSize, ZSTD_compressEnd(ctxDuplicated, compressedBuffer, ZSTD_compressBound(testSize),
+                                          (const char*)CNBuffer + dictSize, testSize) );
+            {   ZSTD_frameHeader zfh;
+                if (ZSTD_getFrameHeader(&zfh, compressedBuffer, cSize)) goto _output_error;
+                if ((zfh.frameContentSize != testSize) && (zfh.frameContentSize != 0)) goto _output_error;
+        }   }
+        DISPLAYLEVEL(3, "OK \n");
+
+        if ((int)(compressibility * 100 + 0.1) == FUZ_compressibility_default) { /* test only valid with known input */
+            size_t const flatdictSize = 22 KB;
+            size_t const contentSize = 9 KB;
+            const void* const dict = (const char*)CNBuffer;
+            const void* const contentStart = (const char*)dict + flatdictSize;
+            size_t const target_nodict_cSize[22+1] = { 3840, 3770, 3870, 3830, 3770,
+                                                       3770, 3770, 3770, 3750, 3750,
+                                                       3740, 3670, 3670, 3660, 3660,
+                                                       3660, 3660, 3660, 3660, 3660,
+                                                       3660, 3660, 3660 };
+            size_t const target_wdict_cSize[22+1] =  { 2830, 2890, 2890, 2820, 2940,
+                                                       2950, 2950, 2920, 2900, 2890,
+                                                       2910, 2910, 2910, 2770, 2760,
+                                                       2750, 2750, 2750, 2750, 2750,
+                                                       2750, 2750, 2750 };
+            int l = 1;
+            int const maxLevel = ZSTD_maxCLevel();
+
+            DISPLAYLEVEL(3, "test%3i : flat-dictionary efficiency test : \n", testNb++);
+            assert(maxLevel == 22);
+            RDG_genBuffer(CNBuffer, flatdictSize + contentSize, compressibility, 0., seed);
+            DISPLAYLEVEL(4, "content hash : %016llx;  dict hash : %016llx \n", XXH64(contentStart, contentSize, 0), XXH64(dict, flatdictSize, 0));
+
+            for ( ; l <= maxLevel; l++) {
+                size_t const nodict_cSize = ZSTD_compress(compressedBuffer, compressedBufferSize,
+                                                          contentStart, contentSize, l);
+                if (nodict_cSize > target_nodict_cSize[l]) {
+                    DISPLAYLEVEL(1, "error : compression at level %i worse than expected (%u > %u) \n",
+                                    l, (unsigned)nodict_cSize, (unsigned)target_nodict_cSize[l]);
+                    goto _output_error;
+                }
+                DISPLAYLEVEL(4, "level %i : max expected %u >= reached %u \n",
+                                l, (unsigned)target_nodict_cSize[l], (unsigned)nodict_cSize);
+            }
+            for ( l=1 ; l <= maxLevel; l++) {
+                size_t const wdict_cSize = ZSTD_compress_usingDict(ctxOrig,
+                                                          compressedBuffer, compressedBufferSize,
+                                                          contentStart, contentSize,
+                                                          dict, flatdictSize,
+                                                          l);
+                if (wdict_cSize > target_wdict_cSize[l]) {
+                    DISPLAYLEVEL(1, "error : compression with dictionary at level %i worse than expected (%u > %u) \n",
+                                    l, (unsigned)wdict_cSize, (unsigned)target_wdict_cSize[l]);
+                    goto _output_error;
+                }
+                DISPLAYLEVEL(4, "level %i with dictionary : max expected %u >= reached %u \n",
+                                l, (unsigned)target_wdict_cSize[l], (unsigned)wdict_cSize);
+            }
+
+            DISPLAYLEVEL(4, "compression efficiency tests OK \n");
+        }
+
+        ZSTD_freeCCtx(ctxOrig);
+        ZSTD_freeCCtx(ctxDuplicated);
+        ZSTD_freeDCtx(dctx);
+    }
+
+    /* Dictionary and dictBuilder tests */
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        size_t const dictBufferCapacity = 16 KB;
+        void* const dictBuffer = malloc(dictBufferCapacity);
+        size_t const totalSampleSize = 1 MB;
+        size_t const sampleUnitSize = 8 KB;
+        U32 const nbSamples = (U32)(totalSampleSize / sampleUnitSize);
+        size_t* const samplesSizes = (size_t*) malloc(nbSamples * sizeof(size_t));
+        size_t dictSize;
+        U32 dictID;
+        size_t dictHeaderSize;
+
+        if (dictBuffer==NULL || samplesSizes==NULL) {
+            free(dictBuffer);
+            free(samplesSizes);
+            goto _output_error;
+        }
+
+        DISPLAYLEVEL(3, "test%3i : dictBuilder on cyclic data : ", testNb++);
+        assert(compressedBufferSize >= totalSampleSize);
+        { U32 u; for (u=0; u<totalSampleSize; u++) ((BYTE*)decodedBuffer)[u] = (BYTE)u; }
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        {   size_t const sDictSize = ZDICT_trainFromBuffer(dictBuffer, dictBufferCapacity,
+                                         decodedBuffer, samplesSizes, nbSamples);
+            if (ZDICT_isError(sDictSize)) goto _output_error;
+            DISPLAYLEVEL(3, "OK, created dictionary of size %u \n", (unsigned)sDictSize);
+        }
+
+        DISPLAYLEVEL(3, "test%3i : dictBuilder : ", testNb++);
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        dictSize = ZDICT_trainFromBuffer(dictBuffer, dictBufferCapacity,
+                                         CNBuffer, samplesSizes, nbSamples);
+        if (ZDICT_isError(dictSize)) goto _output_error;
+        DISPLAYLEVEL(3, "OK, created dictionary of size %u \n", (unsigned)dictSize);
+
+        DISPLAYLEVEL(3, "test%3i : Multithreaded COVER dictBuilder : ", testNb++);
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        {   ZDICT_cover_params_t coverParams;
+            memset(&coverParams, 0, sizeof(coverParams));
+            coverParams.steps = 8;
+            coverParams.nbThreads = 4;
+            dictSize = ZDICT_optimizeTrainFromBuffer_cover(
+                dictBuffer, dictBufferCapacity,
+                CNBuffer, samplesSizes, nbSamples/8,  /* less samples for faster tests */
+                &coverParams);
+            if (ZDICT_isError(dictSize)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK, created dictionary of size %u \n", (unsigned)dictSize);
+
+        DISPLAYLEVEL(3, "test%3i : COVER dictBuilder with shrinkDict: ", testNb++);
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        {   ZDICT_cover_params_t coverParams;
+            memset(&coverParams, 0, sizeof(coverParams));
+            coverParams.steps = 8;
+            coverParams.nbThreads = 4;
+            coverParams.shrinkDict = 1;
+            coverParams.shrinkDictMaxRegression = 1;
+            dictSize = ZDICT_optimizeTrainFromBuffer_cover(
+                dictBuffer, dictBufferCapacity,
+                CNBuffer, samplesSizes, nbSamples/8,  /* less samples for faster tests */
+                &coverParams);
+            if (ZDICT_isError(dictSize)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK, created dictionary of size %u \n", (unsigned)dictSize);
+
+        DISPLAYLEVEL(3, "test%3i : Multithreaded FASTCOVER dictBuilder : ", testNb++);
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        {   ZDICT_fastCover_params_t fastCoverParams;
+            memset(&fastCoverParams, 0, sizeof(fastCoverParams));
+            fastCoverParams.steps = 8;
+            fastCoverParams.nbThreads = 4;
+            dictSize = ZDICT_optimizeTrainFromBuffer_fastCover(
+                dictBuffer, dictBufferCapacity,
+                CNBuffer, samplesSizes, nbSamples,
+                &fastCoverParams);
+            if (ZDICT_isError(dictSize)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK, created dictionary of size %u \n", (unsigned)dictSize);
+
+        DISPLAYLEVEL(3, "test%3i : FASTCOVER dictBuilder with shrinkDict: ", testNb++);
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        {   ZDICT_fastCover_params_t fastCoverParams;
+            memset(&fastCoverParams, 0, sizeof(fastCoverParams));
+            fastCoverParams.steps = 8;
+            fastCoverParams.nbThreads = 4;
+            fastCoverParams.shrinkDict = 1;
+            fastCoverParams.shrinkDictMaxRegression = 1;
+            dictSize = ZDICT_optimizeTrainFromBuffer_fastCover(
+                dictBuffer, dictBufferCapacity,
+                CNBuffer, samplesSizes, nbSamples,
+                &fastCoverParams);
+            if (ZDICT_isError(dictSize)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK, created dictionary of size %u \n", (unsigned)dictSize);
+
+        DISPLAYLEVEL(3, "test%3i : check dictID : ", testNb++);
+        dictID = ZDICT_getDictID(dictBuffer, dictSize);
+        if (dictID==0) goto _output_error;
+        DISPLAYLEVEL(3, "OK : %u \n", (unsigned)dictID);
+
+        DISPLAYLEVEL(3, "test%3i : check dict header size no error : ", testNb++);
+        dictHeaderSize = ZDICT_getDictHeaderSize(dictBuffer, dictSize);
+        if (dictHeaderSize==0) goto _output_error;
+        DISPLAYLEVEL(3, "OK : %u \n", (unsigned)dictHeaderSize);
+
+        DISPLAYLEVEL(3, "test%3i : check dict header size correctness : ", testNb++);
+        {   unsigned char const dictBufferFixed[144] = { 0x37, 0xa4, 0x30, 0xec, 0x63, 0x00, 0x00, 0x00, 0x08, 0x10, 0x00, 0x1f,
+                                                         0x0f, 0x00, 0x28, 0xe5, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                                                         0x00, 0x80, 0x0f, 0x9e, 0x0f, 0x00, 0x00, 0x24, 0x40, 0x80, 0x00, 0x01,
+                                                         0x02, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0xde, 0x08,
+                                                         0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
+                                                         0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
+                                                         0x08, 0x08, 0x08, 0x08, 0xbc, 0xe1, 0x4b, 0x92, 0x0e, 0xb4, 0x7b, 0x18,
+                                                         0x86, 0x61, 0x18, 0xc6, 0x18, 0x63, 0x8c, 0x31, 0xc6, 0x18, 0x63, 0x8c,
+                                                         0x31, 0x66, 0x66, 0x66, 0x66, 0xb6, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x04,
+                                                         0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x20, 0x73, 0x6f, 0x64, 0x61,
+                                                         0x6c, 0x65, 0x73, 0x20, 0x74, 0x6f, 0x72, 0x74, 0x6f, 0x72, 0x20, 0x65,
+                                                         0x6c, 0x65, 0x69, 0x66, 0x65, 0x6e, 0x64, 0x2e, 0x20, 0x41, 0x6c, 0x69 };
+            dictHeaderSize = ZDICT_getDictHeaderSize(dictBufferFixed, 144);
+            if (dictHeaderSize != 115) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK : %u \n", (unsigned)dictHeaderSize);
+
+        DISPLAYLEVEL(3, "test%3i : compress with dictionary : ", testNb++);
+        cSize = ZSTD_compress_usingDict(cctx, compressedBuffer, compressedBufferSize,
+                                        CNBuffer, CNBuffSize,
+                                        dictBuffer, dictSize, 4);
+        if (ZSTD_isError(cSize)) goto _output_error;
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : retrieve dictID from dictionary : ", testNb++);
+        {   U32 const did = ZSTD_getDictID_fromDict(dictBuffer, dictSize);
+            if (did != dictID) goto _output_error;   /* non-conformant (content-only) dictionary */
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : retrieve dictID from frame : ", testNb++);
+        {   U32 const did = ZSTD_getDictID_fromFrame(compressedBuffer, cSize);
+            if (did != dictID) goto _output_error;   /* non-conformant (content-only) dictionary */
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : frame built with dictionary should be decompressible : ", testNb++);
+        {   ZSTD_DCtx* const dctx = ZSTD_createDCtx(); assert(dctx != NULL);
+            CHECKPLUS(r, ZSTD_decompress_usingDict(dctx,
+                                           decodedBuffer, CNBuffSize,
+                                           compressedBuffer, cSize,
+                                           dictBuffer, dictSize),
+                      if (r != CNBuffSize) goto _output_error);
+            ZSTD_freeDCtx(dctx);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : estimate CDict size : ", testNb++);
+        {   ZSTD_compressionParameters const cParams = ZSTD_getCParams(1, CNBuffSize, dictSize);
+            size_t const estimatedSize = ZSTD_estimateCDictSize_advanced(dictSize, cParams, ZSTD_dlm_byRef);
+            DISPLAYLEVEL(3, "OK : %u \n", (unsigned)estimatedSize);
+        }
+
+        DISPLAYLEVEL(3, "test%3i : compress with CDict ", testNb++);
+        {   ZSTD_compressionParameters const cParams = ZSTD_getCParams(1, CNBuffSize, dictSize);
+            ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dictBuffer, dictSize,
+                                            ZSTD_dlm_byRef, ZSTD_dct_auto,
+                                            cParams, ZSTD_defaultCMem);
+            assert(cdict != NULL);
+            DISPLAYLEVEL(3, "(size : %u) : ", (unsigned)ZSTD_sizeof_CDict(cdict));
+            cSize = ZSTD_compress_usingCDict(cctx, compressedBuffer, compressedBufferSize,
+                                                 CNBuffer, CNBuffSize, cdict);
+            ZSTD_freeCDict(cdict);
+            if (ZSTD_isError(cSize)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : retrieve dictID from frame : ", testNb++);
+        {   U32 const did = ZSTD_getDictID_fromFrame(compressedBuffer, cSize);
+            if (did != dictID) goto _output_error;   /* non-conformant (content-only) dictionary */
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : frame built with dictionary should be decompressible : ", testNb++);
+        {   ZSTD_DCtx* const dctx = ZSTD_createDCtx(); assert(dctx != NULL);
+            CHECKPLUS(r, ZSTD_decompress_usingDict(dctx,
+                                           decodedBuffer, CNBuffSize,
+                                           compressedBuffer, cSize,
+                                           dictBuffer, dictSize),
+                      if (r != CNBuffSize) goto _output_error);
+            ZSTD_freeDCtx(dctx);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : compress with static CDict : ", testNb++);
+        {   int const maxLevel = ZSTD_maxCLevel();
+            int level;
+            for (level = 1; level <= maxLevel; ++level) {
+                ZSTD_compressionParameters const cParams = ZSTD_getCParams(level, CNBuffSize, dictSize);
+                size_t const cdictSize = ZSTD_estimateCDictSize_advanced(dictSize, cParams, ZSTD_dlm_byCopy);
+                void* const cdictBuffer = malloc(cdictSize);
+                if (cdictBuffer==NULL) goto _output_error;
+                {   const ZSTD_CDict* const cdict = ZSTD_initStaticCDict(
+                                                cdictBuffer, cdictSize,
+                                                dictBuffer, dictSize,
+                                                ZSTD_dlm_byCopy, ZSTD_dct_auto,
+                                                cParams);
+                    if (cdict == NULL) {
+                        DISPLAY("ZSTD_initStaticCDict failed ");
+                        goto _output_error;
+                    }
+                    cSize = ZSTD_compress_usingCDict(cctx,
+                                    compressedBuffer, compressedBufferSize,
+                                    CNBuffer, MIN(10 KB, CNBuffSize), cdict);
+                    if (ZSTD_isError(cSize)) {
+                        DISPLAY("ZSTD_compress_usingCDict failed ");
+                        goto _output_error;
+                }   }
+                free(cdictBuffer);
+        }   }
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : ZSTD_compress_usingCDict_advanced, no contentSize, no dictID : ", testNb++);
+        {   ZSTD_frameParameters const fParams = { 0 /* frameSize */, 1 /* checksum */, 1 /* noDictID*/ };
+            ZSTD_compressionParameters const cParams = ZSTD_getCParams(1, CNBuffSize, dictSize);
+            ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto, cParams, ZSTD_defaultCMem);
+            assert(cdict != NULL);
+            cSize = ZSTD_compress_usingCDict_advanced(cctx,
+                                                      compressedBuffer, compressedBufferSize,
+                                                      CNBuffer, CNBuffSize,
+                                                      cdict, fParams);
+            ZSTD_freeCDict(cdict);
+            if (ZSTD_isError(cSize)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : try retrieving contentSize from frame : ", testNb++);
+        {   U64 const contentSize = ZSTD_getFrameContentSize(compressedBuffer, cSize);
+            if (contentSize != ZSTD_CONTENTSIZE_UNKNOWN) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK (unknown)\n");
+
+        DISPLAYLEVEL(3, "test%3i : frame built without dictID should be decompressible : ", testNb++);
+        {   ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+            assert(dctx != NULL);
+            CHECKPLUS(r, ZSTD_decompress_usingDict(dctx,
+                                           decodedBuffer, CNBuffSize,
+                                           compressedBuffer, cSize,
+                                           dictBuffer, dictSize),
+                      if (r != CNBuffSize) goto _output_error);
+            ZSTD_freeDCtx(dctx);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : ZSTD_compress_advanced, no dictID : ", testNb++);
+        {   ZSTD_parameters p = ZSTD_getParams(3, CNBuffSize, dictSize);
+            p.fParams.noDictIDFlag = 1;
+            cSize = ZSTD_compress_advanced(cctx, compressedBuffer, compressedBufferSize,
+                                           CNBuffer, CNBuffSize,
+                                           dictBuffer, dictSize, p);
+            if (ZSTD_isError(cSize)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/CNBuffSize*100);
+
+        DISPLAYLEVEL(3, "test%3i : frame built without dictID should be decompressible : ", testNb++);
+        {   ZSTD_DCtx* const dctx = ZSTD_createDCtx(); assert(dctx != NULL);
+            CHECKPLUS(r, ZSTD_decompress_usingDict(dctx,
+                                           decodedBuffer, CNBuffSize,
+                                           compressedBuffer, cSize,
+                                           dictBuffer, dictSize),
+                      if (r != CNBuffSize) goto _output_error);
+            ZSTD_freeDCtx(dctx);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : dictionary containing only header should return error : ", testNb++);
+        {   ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+            assert(dctx != NULL);
+            {   const size_t ret = ZSTD_decompress_usingDict(
+                    dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize,
+                    "\x37\xa4\x30\xec\x11\x22\x33\x44", 8);
+                if (ZSTD_getErrorCode(ret) != ZSTD_error_dictionary_corrupted)
+                    goto _output_error;
+            }
+            ZSTD_freeDCtx(dctx);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Building cdict w/ ZSTD_dct_fullDict on a good dictionary : ", testNb++);
+        {   ZSTD_compressionParameters const cParams = ZSTD_getCParams(1, CNBuffSize, dictSize);
+            ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_fullDict, cParams, ZSTD_defaultCMem);
+            if (cdict==NULL) goto _output_error;
+            ZSTD_freeCDict(cdict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Building cdict w/ ZSTD_dct_fullDict on a rawContent (must fail) : ", testNb++);
+        {   ZSTD_compressionParameters const cParams = ZSTD_getCParams(1, CNBuffSize, dictSize);
+            ZSTD_CDict* const cdict = ZSTD_createCDict_advanced((const char*)dictBuffer+1, dictSize-1, ZSTD_dlm_byRef, ZSTD_dct_fullDict, cParams, ZSTD_defaultCMem);
+            if (cdict!=NULL) goto _output_error;
+            ZSTD_freeCDict(cdict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading rawContent starting with dict header w/ ZSTD_dct_auto should fail : ", testNb++);
+        {
+            size_t ret;
+            MEM_writeLE32((char*)dictBuffer+2, ZSTD_MAGIC_DICTIONARY);
+            /* Either operation is allowed to fail, but one must fail. */
+            ret = ZSTD_CCtx_loadDictionary_advanced(
+                    cctx, (const char*)dictBuffer+2, dictSize-2, ZSTD_dlm_byRef, ZSTD_dct_auto);
+            if (!ZSTD_isError(ret)) {
+                ret = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100));
+                if (!ZSTD_isError(ret)) goto _output_error;
+            }
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading rawContent starting with dict header w/ ZSTD_dct_rawContent should pass : ", testNb++);
+        {
+            size_t ret;
+            MEM_writeLE32((char*)dictBuffer+2, ZSTD_MAGIC_DICTIONARY);
+            ret = ZSTD_CCtx_loadDictionary_advanced(
+                    cctx, (const char*)dictBuffer+2, dictSize-2, ZSTD_dlm_byRef, ZSTD_dct_rawContent);
+            if (ZSTD_isError(ret)) goto _output_error;
+            ret = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100));
+            if (ZSTD_isError(ret)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : ZSTD_CCtx_refCDict() then set parameters : ", testNb++);
+        {   ZSTD_CDict* const cdict = ZSTD_createCDict(CNBuffer, dictSize, 1);
+            CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 1) );
+            CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_hashLog, 12 ));
+            CHECK_Z( ZSTD_CCtx_refCDict(cctx, cdict) );
+            CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 1) );
+            CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_hashLog, 12 ));
+            ZSTD_freeCDict(cdict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading dictionary before setting parameters is the same as loading after : ", testNb++);
+        {
+            size_t size1, size2;
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 7) );
+            CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, CNBuffer, MIN(CNBuffSize, 10 KB)) );
+            size1 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100 KB));
+            if (ZSTD_isError(size1)) goto _output_error;
+
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, CNBuffer, MIN(CNBuffSize, 10 KB)) );
+            CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 7) );
+            size2 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100 KB));
+            if (ZSTD_isError(size2)) goto _output_error;
+
+            if (size1 != size2) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading a dictionary clears the prefix : ", testNb++);
+        {
+            CHECK_Z( ZSTD_CCtx_refPrefix(cctx, (const char*)dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, (const char*)dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100)) );
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading a dictionary clears the cdict : ", testNb++);
+        {
+            ZSTD_CDict* const cdict = ZSTD_createCDict(dictBuffer, dictSize, 1);
+            CHECK_Z( ZSTD_CCtx_refCDict(cctx, cdict) );
+            CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, (const char*)dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100)) );
+            ZSTD_freeCDict(cdict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading a cdict clears the prefix : ", testNb++);
+        {
+            ZSTD_CDict* const cdict = ZSTD_createCDict(dictBuffer, dictSize, 1);
+            CHECK_Z( ZSTD_CCtx_refPrefix(cctx, (const char*)dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_CCtx_refCDict(cctx, cdict) );
+            CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100)) );
+            ZSTD_freeCDict(cdict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading a cdict clears the dictionary : ", testNb++);
+        {
+            ZSTD_CDict* const cdict = ZSTD_createCDict(dictBuffer, dictSize, 1);
+            CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, (const char*)dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_CCtx_refCDict(cctx, cdict) );
+            CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100)) );
+            ZSTD_freeCDict(cdict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading a prefix clears the dictionary : ", testNb++);
+        {
+            CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, (const char*)dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_CCtx_refPrefix(cctx, (const char*)dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100)) );
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loading a prefix clears the cdict : ", testNb++);
+        {
+            ZSTD_CDict* const cdict = ZSTD_createCDict(dictBuffer, dictSize, 1);
+            CHECK_Z( ZSTD_CCtx_refCDict(cctx, cdict) );
+            CHECK_Z( ZSTD_CCtx_refPrefix(cctx, (const char*)dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100)) );
+            ZSTD_freeCDict(cdict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loaded dictionary persists across reset session : ", testNb++);
+        {
+            size_t size1, size2;
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, CNBuffer, MIN(CNBuffSize, 10 KB)) );
+            size1 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100 KB));
+            if (ZSTD_isError(size1)) goto _output_error;
+
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
+            size2 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100 KB));
+            if (ZSTD_isError(size2)) goto _output_error;
+
+            if (size1 != size2) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Loaded dictionary is cleared after resetting parameters : ", testNb++);
+        {
+            size_t size1, size2;
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, CNBuffer, MIN(CNBuffSize, 10 KB)) );
+            size1 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100 KB));
+            if (ZSTD_isError(size1)) goto _output_error;
+
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            size2 = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100 KB));
+            if (ZSTD_isError(size2)) goto _output_error;
+
+            if (size1 == size2) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+        CHECK_Z( ZSTD_CCtx_loadDictionary(cctx, dictBuffer, dictSize) );
+        cSize = ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, CNBuffer, MIN(CNBuffSize, 100 KB));
+        CHECK_Z(cSize);
+        DISPLAYLEVEL(3, "test%3i : ZSTD_decompressDCtx() with dictionary : ", testNb++);
+        {
+            ZSTD_DCtx* dctx = ZSTD_createDCtx();
+            size_t ret;
+            /* We should fail to decompress without a dictionary. */
+            ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters);
+            ret = ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+            if (!ZSTD_isError(ret)) goto _output_error;
+            /* We should succeed to decompress with the dictionary. */
+            ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z( ZSTD_DCtx_loadDictionary(dctx, dictBuffer, dictSize) );
+            CHECK_Z( ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize) );
+            /* The dictionary should presist across calls. */
+            CHECK_Z( ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize) );
+            /* When we reset the context the dictionary is cleared. */
+            ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters);
+            ret = ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+            if (!ZSTD_isError(ret)) goto _output_error;
+            ZSTD_freeDCtx(dctx);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : ZSTD_decompressDCtx() with ddict : ", testNb++);
+        {
+            ZSTD_DCtx* dctx = ZSTD_createDCtx();
+            ZSTD_DDict* ddict = ZSTD_createDDict(dictBuffer, dictSize);
+            size_t ret;
+            /* We should succeed to decompress with the ddict. */
+            ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z( ZSTD_DCtx_refDDict(dctx, ddict) );
+            CHECK_Z( ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize) );
+            /* The ddict should presist across calls. */
+            CHECK_Z( ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize) );
+            /* When we reset the context the ddict is cleared. */
+            ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters);
+            ret = ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+            if (!ZSTD_isError(ret)) goto _output_error;
+            ZSTD_freeDCtx(dctx);
+            ZSTD_freeDDict(ddict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : ZSTD_decompressDCtx() with prefix : ", testNb++);
+        {
+            ZSTD_DCtx* dctx = ZSTD_createDCtx();
+            size_t ret;
+            /* We should succeed to decompress with the prefix. */
+            ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z( ZSTD_DCtx_refPrefix_advanced(dctx, dictBuffer, dictSize, ZSTD_dct_auto) );
+            CHECK_Z( ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize) );
+            /* The prefix should be cleared after the first compression. */
+            ret = ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+            if (!ZSTD_isError(ret)) goto _output_error;
+            ZSTD_freeDCtx(dctx);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Dictionary with non-default repcodes : ", testNb++);
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        dictSize = ZDICT_trainFromBuffer(dictBuffer, dictSize,
+                                         CNBuffer, samplesSizes, nbSamples);
+        if (ZDICT_isError(dictSize)) goto _output_error;
+        /* Set all the repcodes to non-default */
+        {
+            BYTE* dictPtr = (BYTE*)dictBuffer;
+            BYTE* dictLimit = dictPtr + dictSize - 12;
+            /* Find the repcodes */
+            while (dictPtr < dictLimit &&
+                   (MEM_readLE32(dictPtr) != 1 || MEM_readLE32(dictPtr + 4) != 4 ||
+                    MEM_readLE32(dictPtr + 8) != 8)) {
+                ++dictPtr;
+            }
+            if (dictPtr >= dictLimit) goto _output_error;
+            MEM_writeLE32(dictPtr + 0, 10);
+            MEM_writeLE32(dictPtr + 4, 10);
+            MEM_writeLE32(dictPtr + 8, 10);
+            /* Set the last 8 bytes to 'x' */
+            memset((BYTE*)dictBuffer + dictSize - 8, 'x', 8);
+        }
+        /* The optimal parser checks all the repcodes.
+         * Make sure at least one is a match >= targetLength so that it is
+         * immediately chosen. This will make sure that the compressor and
+         * decompressor agree on at least one of the repcodes.
+         */
+        {   size_t dSize;
+            BYTE data[1024];
+            ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+            ZSTD_compressionParameters const cParams = ZSTD_getCParams(19, CNBuffSize, dictSize);
+            ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dictBuffer, dictSize,
+                                            ZSTD_dlm_byRef, ZSTD_dct_auto,
+                                            cParams, ZSTD_defaultCMem);
+            assert(dctx != NULL); assert(cdict != NULL);
+            memset(data, 'x', sizeof(data));
+            cSize = ZSTD_compress_usingCDict(cctx, compressedBuffer, compressedBufferSize,
+                                             data, sizeof(data), cdict);
+            ZSTD_freeCDict(cdict);
+            if (ZSTD_isError(cSize)) { DISPLAYLEVEL(5, "Compression error %s : ", ZSTD_getErrorName(cSize)); goto _output_error; }
+            dSize = ZSTD_decompress_usingDict(dctx, decodedBuffer, sizeof(data), compressedBuffer, cSize, dictBuffer, dictSize);
+            if (ZSTD_isError(dSize)) { DISPLAYLEVEL(5, "Decompression error %s : ", ZSTD_getErrorName(dSize)); goto _output_error; }
+            if (memcmp(data, decodedBuffer, sizeof(data))) { DISPLAYLEVEL(5, "Data corruption : "); goto _output_error; }
+            ZSTD_freeDCtx(dctx);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        ZSTD_freeCCtx(cctx);
+        free(dictBuffer);
+        free(samplesSizes);
+    }
+
+    /* COVER dictionary builder tests */
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        size_t dictSize = 16 KB;
+        size_t optDictSize = dictSize;
+        void* dictBuffer = malloc(dictSize);
+        size_t const totalSampleSize = 1 MB;
+        size_t const sampleUnitSize = 8 KB;
+        U32 const nbSamples = (U32)(totalSampleSize / sampleUnitSize);
+        size_t* const samplesSizes = (size_t*) malloc(nbSamples * sizeof(size_t));
+        U32 seed32 = seed;
+        ZDICT_cover_params_t params;
+        U32 dictID;
+
+        if (dictBuffer==NULL || samplesSizes==NULL) {
+            free(dictBuffer);
+            free(samplesSizes);
+            goto _output_error;
+        }
+
+        DISPLAYLEVEL(3, "test%3i : ZDICT_trainFromBuffer_cover : ", testNb++);
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        memset(&params, 0, sizeof(params));
+        params.d = 1 + (FUZ_rand(&seed32) % 16);
+        params.k = params.d + (FUZ_rand(&seed32) % 256);
+        dictSize = ZDICT_trainFromBuffer_cover(dictBuffer, dictSize,
+                                               CNBuffer, samplesSizes, nbSamples,
+                                               params);
+        if (ZDICT_isError(dictSize)) goto _output_error;
+        DISPLAYLEVEL(3, "OK, created dictionary of size %u \n", (unsigned)dictSize);
+
+        DISPLAYLEVEL(3, "test%3i : check dictID : ", testNb++);
+        dictID = ZDICT_getDictID(dictBuffer, dictSize);
+        if (dictID==0) goto _output_error;
+        DISPLAYLEVEL(3, "OK : %u \n", (unsigned)dictID);
+
+        DISPLAYLEVEL(3, "test%3i : ZDICT_optimizeTrainFromBuffer_cover : ", testNb++);
+        memset(&params, 0, sizeof(params));
+        params.steps = 4;
+        optDictSize = ZDICT_optimizeTrainFromBuffer_cover(dictBuffer, optDictSize,
+                                                          CNBuffer, samplesSizes,
+                                                          nbSamples / 4, &params);
+        if (ZDICT_isError(optDictSize)) goto _output_error;
+        DISPLAYLEVEL(3, "OK, created dictionary of size %u \n", (unsigned)optDictSize);
+
+        DISPLAYLEVEL(3, "test%3i : check dictID : ", testNb++);
+        dictID = ZDICT_getDictID(dictBuffer, optDictSize);
+        if (dictID==0) goto _output_error;
+        DISPLAYLEVEL(3, "OK : %u \n", (unsigned)dictID);
+
+        ZSTD_freeCCtx(cctx);
+        free(dictBuffer);
+        free(samplesSizes);
+    }
+
+    /* Decompression defense tests */
+    DISPLAYLEVEL(3, "test%3i : Check input length for magic number : ", testNb++);
+    { size_t const r = ZSTD_decompress(decodedBuffer, CNBuffSize, CNBuffer, 3);   /* too small input */
+      if (!ZSTD_isError(r)) goto _output_error;
+      if (ZSTD_getErrorCode(r) != ZSTD_error_srcSize_wrong) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : Check magic Number : ", testNb++);
+    ((char*)(CNBuffer))[0] = 1;
+    { size_t const r = ZSTD_decompress(decodedBuffer, CNBuffSize, CNBuffer, 4);
+      if (!ZSTD_isError(r)) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* content size verification test */
+    DISPLAYLEVEL(3, "test%3i : Content size verification : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        size_t const srcSize = 5000;
+        size_t const wrongSrcSize = (srcSize + 1000);
+        ZSTD_parameters params = ZSTD_getParams(1, wrongSrcSize, 0);
+        params.fParams.contentSizeFlag = 1;
+        CHECK( ZSTD_compressBegin_advanced(cctx, NULL, 0, params, wrongSrcSize) );
+        {   size_t const result = ZSTD_compressEnd(cctx, decodedBuffer, CNBuffSize, CNBuffer, srcSize);
+            if (!ZSTD_isError(result)) goto _output_error;
+            if (ZSTD_getErrorCode(result) != ZSTD_error_srcSize_wrong) goto _output_error;
+            DISPLAYLEVEL(3, "OK : %s \n", ZSTD_getErrorName(result));
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+
+    /* negative compression level test : ensure simple API and advanced API produce same result */
+    DISPLAYLEVEL(3, "test%3i : negative compression level : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        size_t const srcSize = CNBuffSize / 5;
+        int const compressionLevel = -1;
+
+        assert(cctx != NULL);
+        {   ZSTD_parameters const params = ZSTD_getParams(compressionLevel, srcSize, 0);
+            size_t const cSize_1pass = ZSTD_compress_advanced(cctx,
+                                        compressedBuffer, compressedBufferSize,
+                                        CNBuffer, srcSize,
+                                        NULL, 0,
+                                        params);
+            if (ZSTD_isError(cSize_1pass)) goto _output_error;
+
+            CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, compressionLevel) );
+            {   size_t const compressionResult = ZSTD_compress2(cctx,
+                                    compressedBuffer, compressedBufferSize,
+                                    CNBuffer, srcSize);
+                DISPLAYLEVEL(5, "simple=%zu vs %zu=advanced : ", cSize_1pass, compressionResult);
+                if (ZSTD_isError(compressionResult)) goto _output_error;
+                if (compressionResult != cSize_1pass) goto _output_error;
+        }   }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* parameters order test */
+    {   size_t const inputSize = CNBuffSize / 2;
+        U64 xxh64;
+
+        {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+            DISPLAYLEVEL(3, "test%3i : parameters in order : ", testNb++);
+            assert(cctx != NULL);
+            CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 2) );
+            CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableLongDistanceMatching, 1) );
+            CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_windowLog, 18) );
+            {   size_t const compressedSize = ZSTD_compress2(cctx,
+                                compressedBuffer, ZSTD_compressBound(inputSize),
+                                CNBuffer, inputSize);
+                CHECK(compressedSize);
+                cSize = compressedSize;
+                xxh64 = XXH64(compressedBuffer, compressedSize, 0);
+            }
+            DISPLAYLEVEL(3, "OK (compress : %u -> %u bytes)\n", (unsigned)inputSize, (unsigned)cSize);
+            ZSTD_freeCCtx(cctx);
+        }
+
+        {   ZSTD_CCtx* cctx = ZSTD_createCCtx();
+            DISPLAYLEVEL(3, "test%3i : parameters disordered : ", testNb++);
+            CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_windowLog, 18) );
+            CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableLongDistanceMatching, 1) );
+            CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, 2) );
+            {   size_t const result = ZSTD_compress2(cctx,
+                                compressedBuffer, ZSTD_compressBound(inputSize),
+                                CNBuffer, inputSize);
+                CHECK(result);
+                if (result != cSize) goto _output_error;   /* must result in same compressed result, hence same size */
+                if (XXH64(compressedBuffer, result, 0) != xxh64) goto _output_error;  /* must result in exactly same content, hence same hash */
+                DISPLAYLEVEL(3, "OK (compress : %u -> %u bytes)\n", (unsigned)inputSize, (unsigned)result);
+            }
+            ZSTD_freeCCtx(cctx);
+        }
+    }
+
+    /* advanced parameters for decompression */
+    {   ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+        assert(dctx != NULL);
+
+        DISPLAYLEVEL(3, "test%3i : get dParameter bounds ", testNb++);
+        {   ZSTD_bounds const bounds = ZSTD_dParam_getBounds(ZSTD_d_windowLogMax);
+            CHECK(bounds.error);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : wrong dParameter : ", testNb++);
+        {   size_t const sr = ZSTD_DCtx_setParameter(dctx, (ZSTD_dParameter)999999, 0);
+            if (!ZSTD_isError(sr)) goto _output_error;
+        }
+        {   ZSTD_bounds const bounds = ZSTD_dParam_getBounds((ZSTD_dParameter)999998);
+            if (!ZSTD_isError(bounds.error)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : out of bound dParameter : ", testNb++);
+        {   size_t const sr = ZSTD_DCtx_setParameter(dctx, ZSTD_d_windowLogMax, 9999);
+            if (!ZSTD_isError(sr)) goto _output_error;
+        }
+        {   size_t const sr = ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, (ZSTD_format_e)888);
+            if (!ZSTD_isError(sr)) goto _output_error;
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        ZSTD_freeDCtx(dctx);
+    }
+
+
+    /* custom formats tests */
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+        size_t const inputSize = CNBuffSize / 2;   /* won't cause pb with small dict size */
+        assert(dctx != NULL); assert(cctx != NULL);
+
+        /* basic block compression */
+        DISPLAYLEVEL(3, "test%3i : magic-less format test : ", testNb++);
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_format, ZSTD_f_zstd1_magicless) );
+        {   ZSTD_inBuffer in = { CNBuffer, inputSize, 0 };
+            ZSTD_outBuffer out = { compressedBuffer, ZSTD_compressBound(inputSize), 0 };
+            size_t const result = ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+            if (result != 0) goto _output_error;
+            if (in.pos != in.size) goto _output_error;
+            cSize = out.pos;
+        }
+        DISPLAYLEVEL(3, "OK (compress : %u -> %u bytes)\n", (unsigned)inputSize, (unsigned)cSize);
+
+        DISPLAYLEVEL(3, "test%3i : decompress normally (should fail) : ", testNb++);
+        {   size_t const decodeResult = ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+            if (ZSTD_getErrorCode(decodeResult) != ZSTD_error_prefix_unknown) goto _output_error;
+            DISPLAYLEVEL(3, "OK : %s \n", ZSTD_getErrorName(decodeResult));
+        }
+
+        DISPLAYLEVEL(3, "test%3i : decompress of magic-less frame : ", testNb++);
+        ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters);
+        CHECK( ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, ZSTD_f_zstd1_magicless) );
+        {   ZSTD_frameHeader zfh;
+            size_t const zfhrt = ZSTD_getFrameHeader_advanced(&zfh, compressedBuffer, cSize, ZSTD_f_zstd1_magicless);
+            if (zfhrt != 0) goto _output_error;
+        }
+        /* one shot */
+        {   size_t const result = ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+            if (result != inputSize) goto _output_error;
+            DISPLAYLEVEL(3, "one-shot OK, ");
+        }
+        /* streaming */
+        {   ZSTD_inBuffer in = { compressedBuffer, cSize, 0 };
+            ZSTD_outBuffer out = { decodedBuffer, CNBuffSize, 0 };
+            size_t const result = ZSTD_decompressStream(dctx, &out, &in);
+            if (result != 0) goto _output_error;
+            if (in.pos != in.size) goto _output_error;
+            if (out.pos != inputSize) goto _output_error;
+            DISPLAYLEVEL(3, "streaming OK : regenerated %u bytes \n", (unsigned)out.pos);
+        }
+
+        /* basic block compression */
+        DISPLAYLEVEL(3, "test%3i : empty magic-less format test : ", testNb++);
+        CHECK( ZSTD_CCtx_setParameter(cctx, ZSTD_c_format, ZSTD_f_zstd1_magicless) );
+        {   ZSTD_inBuffer in = { CNBuffer, 0, 0 };
+            ZSTD_outBuffer out = { compressedBuffer, ZSTD_compressBound(0), 0 };
+            size_t const result = ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
+            if (result != 0) goto _output_error;
+            if (in.pos != in.size) goto _output_error;
+            cSize = out.pos;
+        }
+        DISPLAYLEVEL(3, "OK (compress : %u -> %u bytes)\n", (unsigned)0, (unsigned)cSize);
+
+        DISPLAYLEVEL(3, "test%3i : decompress of empty magic-less frame : ", testNb++);
+        ZSTD_DCtx_reset(dctx, ZSTD_reset_session_and_parameters);
+        CHECK( ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, ZSTD_f_zstd1_magicless) );
+        /* one shot */
+        {   size_t const result = ZSTD_decompressDCtx(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize);
+            if (result != 0) goto _output_error;
+            DISPLAYLEVEL(3, "one-shot OK, ");
+        }
+        /* streaming */
+        {   ZSTD_inBuffer in = { compressedBuffer, cSize, 0 };
+            ZSTD_outBuffer out = { decodedBuffer, CNBuffSize, 0 };
+            size_t const result = ZSTD_decompressStream(dctx, &out, &in);
+            if (result != 0) goto _output_error;
+            if (in.pos != in.size) goto _output_error;
+            if (out.pos != 0) goto _output_error;
+            DISPLAYLEVEL(3, "streaming OK : regenerated %u bytes \n", (unsigned)out.pos);
+        }
+
+        ZSTD_freeCCtx(cctx);
+        ZSTD_freeDCtx(dctx);
+    }
+
+    /* block API tests */
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+        static const size_t dictSize = 65 KB;
+        static const size_t blockSize = 100 KB;   /* won't cause pb with small dict size */
+        size_t cSize2;
+        assert(cctx != NULL); assert(dctx != NULL);
+
+        /* basic block compression */
+        DISPLAYLEVEL(3, "test%3i : Block compression test : ", testNb++);
+        CHECK( ZSTD_compressBegin(cctx, 5) );
+        CHECK( ZSTD_getBlockSize(cctx) >= blockSize);
+        CHECK_VAR(cSize, ZSTD_compressBlock(cctx, compressedBuffer, ZSTD_compressBound(blockSize), CNBuffer, blockSize) );
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Block decompression test : ", testNb++);
+        CHECK( ZSTD_decompressBegin(dctx) );
+        { CHECK_NEWV(r, ZSTD_decompressBlock(dctx, decodedBuffer, CNBuffSize, compressedBuffer, cSize) );
+          if (r != blockSize) goto _output_error; }
+        DISPLAYLEVEL(3, "OK \n");
+
+        /* very long stream of block compression */
+        DISPLAYLEVEL(3, "test%3i : Huge block streaming compression test : ", testNb++);
+        CHECK( ZSTD_compressBegin(cctx, -199) );  /* we just want to quickly overflow internal U32 index */
+        CHECK( ZSTD_getBlockSize(cctx) >= blockSize);
+        {   U64 const toCompress = 5000000000ULL;   /* > 4 GB */
+            U64 compressed = 0;
+            while (compressed < toCompress) {
+                size_t const blockCSize = ZSTD_compressBlock(cctx, compressedBuffer, ZSTD_compressBound(blockSize), CNBuffer, blockSize);
+                assert(blockCSize != 0);
+                if (ZSTD_isError(blockCSize)) goto _output_error;
+                compressed += blockCSize;
+        }   }
+        DISPLAYLEVEL(3, "OK \n");
+
+        /* dictionary block compression */
+        DISPLAYLEVEL(3, "test%3i : Dictionary Block compression test : ", testNb++);
+        CHECK( ZSTD_compressBegin_usingDict(cctx, CNBuffer, dictSize, 5) );
+        CHECK_VAR(cSize,  ZSTD_compressBlock(cctx, compressedBuffer, ZSTD_compressBound(blockSize), (char*)CNBuffer+dictSize, blockSize));
+        RDG_genBuffer((char*)CNBuffer+dictSize+blockSize, blockSize, 0.0, 0.0, seed);  /* create a non-compressible second block */
+        { CHECK_NEWV(r, ZSTD_compressBlock(cctx, (char*)compressedBuffer+cSize, ZSTD_compressBound(blockSize), (char*)CNBuffer+dictSize+blockSize, blockSize) );  /* for cctx history consistency */
+          assert(r == 0); /* non-compressible block */ }
+        memcpy((char*)compressedBuffer+cSize, (char*)CNBuffer+dictSize+blockSize, blockSize);   /* send non-compressed block (without header) */
+        CHECK_VAR(cSize2, ZSTD_compressBlock(cctx, (char*)compressedBuffer+cSize+blockSize, ZSTD_compressBound(blockSize),
+                                                   (char*)CNBuffer+dictSize+2*blockSize, blockSize));
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Dictionary Block decompression test : ", testNb++);
+        CHECK( ZSTD_decompressBegin_usingDict(dctx, CNBuffer, dictSize) );
+        {   CHECK_NEWV( r, ZSTD_decompressBlock(dctx, decodedBuffer, blockSize, compressedBuffer, cSize) );
+            if (r != blockSize) {
+                DISPLAYLEVEL(1, "ZSTD_decompressBlock() with _usingDict() fails : %u, instead of %u expected \n", (unsigned)r, (unsigned)blockSize);
+                goto _output_error;
+        }   }
+        memcpy((char*)decodedBuffer+blockSize, (char*)compressedBuffer+cSize, blockSize);
+        ZSTD_insertBlock(dctx, (char*)decodedBuffer+blockSize, blockSize);   /* insert non-compressed block into dctx history */
+        {   CHECK_NEWV( r, ZSTD_decompressBlock(dctx, (char*)decodedBuffer+2*blockSize, blockSize, (char*)compressedBuffer+cSize+blockSize, cSize2) );
+            if (r != blockSize) {
+                DISPLAYLEVEL(1, "ZSTD_decompressBlock() with _usingDict() and after insertBlock() fails : %u, instead of %u expected \n", (unsigned)r, (unsigned)blockSize);
+                goto _output_error;
+        }   }
+        assert(memcpy((char*)CNBuffer+dictSize, decodedBuffer, blockSize*3));  /* ensure regenerated content is identical to origin */
+        DISPLAYLEVEL(3, "OK \n");
+
+        DISPLAYLEVEL(3, "test%3i : Block compression with CDict : ", testNb++);
+        {   ZSTD_CDict* const cdict = ZSTD_createCDict(CNBuffer, dictSize, 3);
+            if (cdict==NULL) goto _output_error;
+            CHECK( ZSTD_compressBegin_usingCDict(cctx, cdict) );
+            CHECK( ZSTD_compressBlock(cctx, compressedBuffer, ZSTD_compressBound(blockSize), (char*)CNBuffer+dictSize, blockSize) );
+            ZSTD_freeCDict(cdict);
+        }
+        DISPLAYLEVEL(3, "OK \n");
+
+        ZSTD_freeCCtx(cctx);
+        ZSTD_freeDCtx(dctx);
+    }
+
+    /* long rle test */
+    {   size_t sampleSize = 0;
+        size_t expectedCompressedSize = 39; /* block 1, 2: compressed, block 3: RLE, zstd 1.4.4 */
+        DISPLAYLEVEL(3, "test%3i : Long RLE test : ", testNb++);
+        memset((char*)CNBuffer+sampleSize, 'B', 256 KB - 1);
+        sampleSize += 256 KB - 1;
+        memset((char*)CNBuffer+sampleSize, 'A', 96 KB);
+        sampleSize += 96 KB;
+        cSize = ZSTD_compress(compressedBuffer, ZSTD_compressBound(sampleSize), CNBuffer, sampleSize, 1);
+        if (ZSTD_isError(cSize) || cSize > expectedCompressedSize) goto _output_error;
+        { CHECK_NEWV(regenSize, ZSTD_decompress(decodedBuffer, sampleSize, compressedBuffer, cSize));
+          if (regenSize!=sampleSize) goto _output_error; }
+        DISPLAYLEVEL(3, "OK \n");
+    }
+
+    DISPLAYLEVEL(3, "test%3i : ZSTD_getSequences decode from sequences test : ", testNb++);
+    {
+        size_t srcSize = 100 KB;
+        BYTE* src = (BYTE*)CNBuffer;
+        BYTE* decoded = (BYTE*)compressedBuffer;
+
+        ZSTD_CCtx* cctx = ZSTD_createCCtx();
+        ZSTD_Sequence* seqs = (ZSTD_Sequence*)malloc(srcSize * sizeof(ZSTD_Sequence));
+        size_t seqsSize;
+
+        if (seqs == NULL) goto _output_error;
+        assert(cctx != NULL);
+
+        /* Populate src with random data */
+        RDG_genBuffer(CNBuffer, srcSize, compressibility, 0., seed);
+
+        /* get the sequences */
+        seqsSize = ZSTD_getSequences(cctx, seqs, srcSize, src, srcSize);
+
+        /* "decode" and compare the sequences */
+        FUZ_decodeSequences(decoded, seqs, seqsSize, src, srcSize);
+        assert(!memcmp(CNBuffer, compressedBuffer, srcSize));
+
+        ZSTD_freeCCtx(cctx);
+        free(seqs);
+    }
+
+    /* Multiple blocks of zeros test */
+    #define LONGZEROSLENGTH 1000000 /* 1MB of zeros */
+    DISPLAYLEVEL(3, "test%3i : compress %u zeroes : ", testNb++, LONGZEROSLENGTH);
+    memset(CNBuffer, 0, LONGZEROSLENGTH);
+    CHECK_VAR(cSize, ZSTD_compress(compressedBuffer, ZSTD_compressBound(LONGZEROSLENGTH), CNBuffer, LONGZEROSLENGTH, 1) );
+    DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/LONGZEROSLENGTH*100);
+
+    DISPLAYLEVEL(3, "test%3i : decompress %u zeroes : ", testNb++, LONGZEROSLENGTH);
+    { CHECK_NEWV(r, ZSTD_decompress(decodedBuffer, LONGZEROSLENGTH, compressedBuffer, cSize) );
+      if (r != LONGZEROSLENGTH) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* All zeroes test (test bug #137) */
+    #define ZEROESLENGTH 100
+    DISPLAYLEVEL(3, "test%3i : compress %u zeroes : ", testNb++, ZEROESLENGTH);
+    memset(CNBuffer, 0, ZEROESLENGTH);
+    CHECK_VAR(cSize, ZSTD_compress(compressedBuffer, ZSTD_compressBound(ZEROESLENGTH), CNBuffer, ZEROESLENGTH, 1) );
+    DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/ZEROESLENGTH*100);
+
+    DISPLAYLEVEL(3, "test%3i : decompress %u zeroes : ", testNb++, ZEROESLENGTH);
+    { CHECK_NEWV(r, ZSTD_decompress(decodedBuffer, ZEROESLENGTH, compressedBuffer, cSize) );
+      if (r != ZEROESLENGTH) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* nbSeq limit test */
+    #define _3BYTESTESTLENGTH 131000
+    #define NB3BYTESSEQLOG   9
+    #define NB3BYTESSEQ     (1 << NB3BYTESSEQLOG)
+    #define NB3BYTESSEQMASK (NB3BYTESSEQ-1)
+    /* creates a buffer full of 3-bytes sequences */
+    {   BYTE _3BytesSeqs[NB3BYTESSEQ][3];
+        U32 rSeed = 1;
+
+        /* create batch of 3-bytes sequences */
+        {   int i;
+            for (i=0; i < NB3BYTESSEQ; i++) {
+                _3BytesSeqs[i][0] = (BYTE)(FUZ_rand(&rSeed) & 255);
+                _3BytesSeqs[i][1] = (BYTE)(FUZ_rand(&rSeed) & 255);
+                _3BytesSeqs[i][2] = (BYTE)(FUZ_rand(&rSeed) & 255);
+        }   }
+
+        /* randomly fills CNBuffer with prepared 3-bytes sequences */
+        {   int i;
+            for (i=0; i < _3BYTESTESTLENGTH; i += 3) {   /* note : CNBuffer size > _3BYTESTESTLENGTH+3 */
+                U32 const id = FUZ_rand(&rSeed) & NB3BYTESSEQMASK;
+                ((BYTE*)CNBuffer)[i+0] = _3BytesSeqs[id][0];
+                ((BYTE*)CNBuffer)[i+1] = _3BytesSeqs[id][1];
+                ((BYTE*)CNBuffer)[i+2] = _3BytesSeqs[id][2];
+    }   }   }
+    DISPLAYLEVEL(3, "test%3i : growing nbSeq : ", testNb++);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        size_t const maxNbSeq = _3BYTESTESTLENGTH / 3;
+        size_t const bound = ZSTD_compressBound(_3BYTESTESTLENGTH);
+        size_t nbSeq = 1;
+        while (nbSeq <= maxNbSeq) {
+          CHECK(ZSTD_compressCCtx(cctx, compressedBuffer, bound, CNBuffer, nbSeq * 3, 19));
+          /* Check every sequence for the first 100, then skip more rapidly. */
+          if (nbSeq < 100) {
+            ++nbSeq;
+          } else {
+            nbSeq += (nbSeq >> 2);
+          }
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : compress lots 3-bytes sequences : ", testNb++);
+    CHECK_VAR(cSize, ZSTD_compress(compressedBuffer, ZSTD_compressBound(_3BYTESTESTLENGTH),
+                                   CNBuffer, _3BYTESTESTLENGTH, 19) );
+    DISPLAYLEVEL(3, "OK (%u bytes : %.2f%%)\n", (unsigned)cSize, (double)cSize/_3BYTESTESTLENGTH*100);
+
+    DISPLAYLEVEL(3, "test%3i : decompress lots 3-bytes sequence : ", testNb++);
+    { CHECK_NEWV(r, ZSTD_decompress(decodedBuffer, _3BYTESTESTLENGTH, compressedBuffer, cSize) );
+      if (r != _3BYTESTESTLENGTH) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+
+    DISPLAYLEVEL(3, "test%3i : growing literals buffer : ", testNb++);
+    RDG_genBuffer(CNBuffer, CNBuffSize, 0.0, 0.1, seed);
+    {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        size_t const bound = ZSTD_compressBound(CNBuffSize);
+        size_t size = 1;
+        while (size <= CNBuffSize) {
+          CHECK(ZSTD_compressCCtx(cctx, compressedBuffer, bound, CNBuffer, size, 3));
+          /* Check every size for the first 100, then skip more rapidly. */
+          if (size < 100) {
+            ++size;
+          } else {
+            size += (size >> 2);
+          }
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : incompressible data and ill suited dictionary : ", testNb++);
+    {   /* Train a dictionary on low characters */
+        size_t dictSize = 16 KB;
+        void* const dictBuffer = malloc(dictSize);
+        size_t const totalSampleSize = 1 MB;
+        size_t const sampleUnitSize = 8 KB;
+        U32 const nbSamples = (U32)(totalSampleSize / sampleUnitSize);
+        size_t* const samplesSizes = (size_t*) malloc(nbSamples * sizeof(size_t));
+        if (!dictBuffer || !samplesSizes) goto _output_error;
+        { U32 u; for (u=0; u<nbSamples; u++) samplesSizes[u] = sampleUnitSize; }
+        dictSize = ZDICT_trainFromBuffer(dictBuffer, dictSize, CNBuffer, samplesSizes, nbSamples);
+        if (ZDICT_isError(dictSize)) goto _output_error;
+        /* Reverse the characters to make the dictionary ill suited */
+        {   U32 u;
+            for (u = 0; u < CNBuffSize; ++u) {
+              ((BYTE*)CNBuffer)[u] = 255 - ((BYTE*)CNBuffer)[u];
+            }
+        }
+        {   /* Compress the data */
+            size_t const inputSize = 500;
+            size_t const outputSize = ZSTD_compressBound(inputSize);
+            void* const outputBuffer = malloc(outputSize);
+            ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+            if (!outputBuffer || !cctx) goto _output_error;
+            CHECK(ZSTD_compress_usingDict(cctx, outputBuffer, outputSize, CNBuffer, inputSize, dictBuffer, dictSize, 1));
+            free(outputBuffer);
+            ZSTD_freeCCtx(cctx);
+        }
+
+        free(dictBuffer);
+        free(samplesSizes);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+
+    /* findFrameCompressedSize on skippable frames */
+    DISPLAYLEVEL(3, "test%3i : frame compressed size of skippable frame : ", testNb++);
+    {   const char* frame = "\x50\x2a\x4d\x18\x05\x0\x0\0abcde";
+        size_t const frameSrcSize = 13;
+        if (ZSTD_findFrameCompressedSize(frame, frameSrcSize) != frameSrcSize) goto _output_error; }
+    DISPLAYLEVEL(3, "OK \n");
+
+    /* error string tests */
+    DISPLAYLEVEL(3, "test%3i : testing ZSTD error code strings : ", testNb++);
+    if (strcmp("No error detected", ZSTD_getErrorName((ZSTD_ErrorCode)(0-ZSTD_error_no_error))) != 0) goto _output_error;
+    if (strcmp("No error detected", ZSTD_getErrorString(ZSTD_error_no_error)) != 0) goto _output_error;
+    if (strcmp("Unspecified error code", ZSTD_getErrorString((ZSTD_ErrorCode)(0-ZSTD_error_GENERIC))) != 0) goto _output_error;
+    if (strcmp("Error (generic)", ZSTD_getErrorName((size_t)0-ZSTD_error_GENERIC)) != 0) goto _output_error;
+    if (strcmp("Error (generic)", ZSTD_getErrorString(ZSTD_error_GENERIC)) != 0) goto _output_error;
+    if (strcmp("No error detected", ZSTD_getErrorName(ZSTD_error_GENERIC)) != 0) goto _output_error;
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : testing ZSTD dictionary sizes : ", testNb++);
+    RDG_genBuffer(CNBuffer, CNBuffSize, compressibility, 0., seed);
+    {
+        size_t const size = MIN(128 KB, CNBuffSize);
+        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
+        ZSTD_CDict* const lgCDict = ZSTD_createCDict(CNBuffer, size, 1);
+        ZSTD_CDict* const smCDict = ZSTD_createCDict(CNBuffer, 1 KB, 1);
+        ZSTD_frameHeader lgHeader;
+        ZSTD_frameHeader smHeader;
+
+        CHECK_Z(ZSTD_compress_usingCDict(cctx, compressedBuffer, compressedBufferSize, CNBuffer, size, lgCDict));
+        CHECK_Z(ZSTD_getFrameHeader(&lgHeader, compressedBuffer, compressedBufferSize));
+        CHECK_Z(ZSTD_compress_usingCDict(cctx, compressedBuffer, compressedBufferSize, CNBuffer, size, smCDict));
+        CHECK_Z(ZSTD_getFrameHeader(&smHeader, compressedBuffer, compressedBufferSize));
+
+        if (lgHeader.windowSize != smHeader.windowSize) goto _output_error;
+
+        ZSTD_freeCDict(smCDict);
+        ZSTD_freeCDict(lgCDict);
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : testing FSE_normalizeCount() PR#1255: ", testNb++);
+    {
+        short norm[32];
+        unsigned count[32];
+        unsigned const tableLog = 5;
+        size_t const nbSeq = 32;
+        unsigned const maxSymbolValue = 31;
+        size_t i;
+
+        for (i = 0; i < 32; ++i)
+            count[i] = 1;
+        /* Calling FSE_normalizeCount() on a uniform distribution should not
+         * cause a division by zero.
+         */
+        FSE_normalizeCount(norm, tableLog, count, nbSeq, maxSymbolValue);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+#ifdef ZSTD_MULTITHREAD
+    DISPLAYLEVEL(3, "test%3i : passing wrong full dict should fail on compressStream2 refPrefix ", testNb++);
+    {
+        ZSTD_CCtx* cctx = ZSTD_createCCtx();
+         /* A little more than ZSTDMT_JOBSIZE_MIN */
+        size_t const srcSize = 1 MB + 5;
+        size_t const dstSize = ZSTD_compressBound(srcSize);
+        void* const src = CNBuffer;
+        void* const dst = compressedBuffer;
+        void* dict = (void*)malloc(srcSize);
+
+        RDG_genBuffer(src, srcSize, compressibility, 0.5, seed);
+        RDG_genBuffer(dict, srcSize, compressibility, 0., seed);
+
+        /* Make sure there is no ZSTD_MAGIC_NUMBER */
+        memset(dict, 0, sizeof(U32));
+
+        /* something more than 1 */
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 2));
+        /* lie and claim this is a full dict */
+        CHECK_Z(ZSTD_CCtx_refPrefix_advanced(cctx, dict, srcSize, ZSTD_dct_fullDict));
+
+        {
+            ZSTD_outBuffer out = {dst, dstSize, 0};
+            ZSTD_inBuffer in = {src, srcSize, 0};
+
+            /* should fail because its not a full dict like we said it was */
+            assert(ZSTD_isError(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush)));
+        }
+
+        ZSTD_freeCCtx(cctx);
+        free(dict);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+    DISPLAYLEVEL(3, "test%3i : small dictionary with multithreading and LDM ", testNb++);
+    {
+        ZSTD_CCtx* cctx = ZSTD_createCCtx();
+        /* A little more than ZSTDMT_JOBSIZE_MIN */
+        size_t const srcSize = 1 MB + 5;
+        size_t const dictSize = 10;
+        size_t const dstSize = ZSTD_compressBound(srcSize);
+        void* const src = CNBuffer;
+        void* const dst = compressedBuffer;
+        void* dict = (void*)malloc(dictSize);
+
+        RDG_genBuffer(src, srcSize, compressibility, 0.5, seed);
+        RDG_genBuffer(dict, dictSize, compressibility, 0., seed);
+
+        /* Make sure there is no ZSTD_MAGIC_NUMBER */
+        memset(dict, 0, sizeof(U32));
+
+        /* Enable MT, LDM, and use refPrefix() for a small dict */
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 2));
+        CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_enableLongDistanceMatching, 1));
+        CHECK_Z(ZSTD_CCtx_refPrefix(cctx, dict, dictSize));
+
+        CHECK_Z(ZSTD_compress2(cctx, dst, dstSize, src, srcSize));
+
+        ZSTD_freeCCtx(cctx);
+        free(dict);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+#endif
+
+    /* note : this test is rather long, it would be great to find a way to speed up its execution */
+    DISPLAYLEVEL(3, "test%3i : table cleanliness through index reduction : ", testNb++);
+    {
+        int cLevel;
+        size_t approxIndex = 0;
+        size_t maxIndex = ((3U << 29) + (1U << ZSTD_WINDOWLOG_MAX)); /* ZSTD_CURRENT_MAX from zstd_compress_internal.h */
+
+        /* Provision enough space in a static context so that we can do all
+         * this without ever reallocating, which would reset the indices. */
+        size_t const staticCCtxSize = ZSTD_estimateCStreamSize(22);
+        void* const staticCCtxBuffer = malloc(staticCCtxSize);
+        ZSTD_CCtx* const cctx = ZSTD_initStaticCCtx(staticCCtxBuffer, staticCCtxSize);
+
+        /* bump the indices so the following compressions happen at high
+         * indices. */
+        {   ZSTD_outBuffer out = { compressedBuffer, compressedBufferSize, 0 };
+            ZSTD_inBuffer in = { CNBuffer, CNBuffSize, 0 };
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, -500));
+            while (approxIndex <= (maxIndex / 4) * 3) {
+                CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush));
+                approxIndex += in.pos;
+                CHECK(in.pos == in.size);
+                in.pos = 0;
+                out.pos = 0;
+            }
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end));
+        }
+
+        /* spew a bunch of stuff into the table area */
+        for (cLevel = 1; cLevel <= 22; cLevel++) {
+            ZSTD_outBuffer out = { compressedBuffer, compressedBufferSize / (unsigned)cLevel, 0 };
+            ZSTD_inBuffer in = { CNBuffer, CNBuffSize, 0 };
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, cLevel));
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush));
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end));
+            approxIndex += in.pos;
+        }
+
+        /* now crank the indices so we overflow */
+        {   ZSTD_outBuffer out = { compressedBuffer, compressedBufferSize, 0 };
+            ZSTD_inBuffer in = { CNBuffer, CNBuffSize, 0 };
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, -500));
+            while (approxIndex <= maxIndex) {
+                CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush));
+                approxIndex += in.pos;
+                CHECK(in.pos == in.size);
+                in.pos = 0;
+                out.pos = 0;
+            }
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end));
+        }
+
+        /* do a bunch of compressions again in low indices and ensure we don't
+         * hit untracked invalid indices */
+        for (cLevel = 1; cLevel <= 22; cLevel++) {
+            ZSTD_outBuffer out = { compressedBuffer, compressedBufferSize / (unsigned)cLevel, 0 };
+            ZSTD_inBuffer in = { CNBuffer, CNBuffSize, 0 };
+            ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, cLevel));
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush));
+            CHECK_Z(ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end));
+            approxIndex += in.pos;
+        }
+
+        free(staticCCtxBuffer);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
+_end:
+    free(CNBuffer);
+    free(compressedBuffer);
+    free(decodedBuffer);
+    return testResult;
+
+_output_error:
+    testResult = 1;
+    DISPLAY("Error detected in Unit tests ! \n");
+    goto _end;
+}
+
+
+static size_t findDiff(const void* buf1, const void* buf2, size_t max)
+{
+    const BYTE* b1 = (const BYTE*)buf1;
+    const BYTE* b2 = (const BYTE*)buf2;
+    size_t u;
+    for (u=0; u<max; u++) {
+        if (b1[u] != b2[u]) break;
+    }
+    return u;
+}
+
+
+static ZSTD_parameters FUZ_makeParams(ZSTD_compressionParameters cParams, ZSTD_frameParameters fParams)
+{
+    ZSTD_parameters params;
+    params.cParams = cParams;
+    params.fParams = fParams;
+    return params;
+}
+
+static size_t FUZ_rLogLength(U32* seed, U32 logLength)
+{
+    size_t const lengthMask = ((size_t)1 << logLength) - 1;
+    return (lengthMask+1) + (FUZ_rand(seed) & lengthMask);
+}
+
+static size_t FUZ_randomLength(U32* seed, U32 maxLog)
+{
+    U32 const logLength = FUZ_rand(seed) % maxLog;
+    return FUZ_rLogLength(seed, logLength);
+}
+
+#undef CHECK
+#define CHECK(cond, ...) {                                    \
+    if (cond) {                                               \
+        DISPLAY("Error => ");                                 \
+        DISPLAY(__VA_ARGS__);                                 \
+        DISPLAY(" (seed %u, test nb %u)  \n", (unsigned)seed, testNb);  \
+        goto _output_error;                                   \
+}   }
+
+#undef CHECK_Z
+#define CHECK_Z(f) {                                          \
+    size_t const err = f;                                     \
+    if (ZSTD_isError(err)) {                                  \
+        DISPLAY("Error => %s : %s ",                          \
+                #f, ZSTD_getErrorName(err));                  \
+        DISPLAY(" (seed %u, test nb %u)  \n", (unsigned)seed, testNb);  \
+        goto _output_error;                                   \
+}   }
+
+
+static int fuzzerTests(U32 seed, unsigned nbTests, unsigned startTest, U32 const maxDurationS, double compressibility, int bigTests)
+{
+    static const U32 maxSrcLog = 23;
+    static const U32 maxSampleLog = 22;
+    size_t const srcBufferSize = (size_t)1<<maxSrcLog;
+    size_t const dstBufferSize = (size_t)1<<maxSampleLog;
+    size_t const cBufferSize   = ZSTD_compressBound(dstBufferSize);
+    BYTE* cNoiseBuffer[5];
+    BYTE* const cBuffer = (BYTE*) malloc (cBufferSize);
+    BYTE* const dstBuffer = (BYTE*) malloc (dstBufferSize);
+    BYTE* const mirrorBuffer = (BYTE*) malloc (dstBufferSize);
+    ZSTD_CCtx* const refCtx = ZSTD_createCCtx();
+    ZSTD_CCtx* const ctx = ZSTD_createCCtx();
+    ZSTD_DCtx* const dctx = ZSTD_createDCtx();
+    U32 result = 0;
+    unsigned testNb = 0;
+    U32 coreSeed = seed;
+    UTIL_time_t const startClock = UTIL_getTime();
+    U64 const maxClockSpan = maxDurationS * SEC_TO_MICRO;
+    int const cLevelLimiter = bigTests ? 3 : 2;
+
+    /* allocation */
+    cNoiseBuffer[0] = (BYTE*)malloc (srcBufferSize);
+    cNoiseBuffer[1] = (BYTE*)malloc (srcBufferSize);
+    cNoiseBuffer[2] = (BYTE*)malloc (srcBufferSize);
+    cNoiseBuffer[3] = (BYTE*)malloc (srcBufferSize);
+    cNoiseBuffer[4] = (BYTE*)malloc (srcBufferSize);
+    CHECK (!cNoiseBuffer[0] || !cNoiseBuffer[1] || !cNoiseBuffer[2] || !cNoiseBuffer[3] || !cNoiseBuffer[4]
+           || !dstBuffer || !mirrorBuffer || !cBuffer || !refCtx || !ctx || !dctx,
+           "Not enough memory, fuzzer tests cancelled");
+
+    /* Create initial samples */
+    RDG_genBuffer(cNoiseBuffer[0], srcBufferSize, 0.00, 0., coreSeed);    /* pure noise */
+    RDG_genBuffer(cNoiseBuffer[1], srcBufferSize, 0.05, 0., coreSeed);    /* barely compressible */
+    RDG_genBuffer(cNoiseBuffer[2], srcBufferSize, compressibility, 0., coreSeed);
+    RDG_genBuffer(cNoiseBuffer[3], srcBufferSize, 0.95, 0., coreSeed);    /* highly compressible */
+    RDG_genBuffer(cNoiseBuffer[4], srcBufferSize, 1.00, 0., coreSeed);    /* sparse content */
+
+    /* catch up testNb */
+    for (testNb=1; testNb < startTest; testNb++) FUZ_rand(&coreSeed);
+
+    /* main test loop */
+    for ( ; (testNb <= nbTests) || (UTIL_clockSpanMicro(startClock) < maxClockSpan); testNb++ ) {
+        BYTE* srcBuffer;   /* jumping pointer */
+        U32 lseed;
+        size_t sampleSize, maxTestSize, totalTestSize;
+        size_t cSize, totalCSize, totalGenSize;
+        U64 crcOrig;
+        BYTE* sampleBuffer;
+        const BYTE* dict;
+        size_t dictSize;
+
+        /* notification */
+        if (nbTests >= testNb) { DISPLAYUPDATE(2, "\r%6u/%6u    ", testNb, nbTests); }
+        else { DISPLAYUPDATE(2, "\r%6u          ", testNb); }
+
+        FUZ_rand(&coreSeed);
+        { U32 const prime1 = 2654435761U; lseed = coreSeed ^ prime1; }
+
+        /* srcBuffer selection [0-4] */
+        {   U32 buffNb = FUZ_rand(&lseed) & 0x7F;
+            if (buffNb & 7) buffNb=2;   /* most common : compressible (P) */
+            else {
+                buffNb >>= 3;
+                if (buffNb & 7) {
+                    const U32 tnb[2] = { 1, 3 };   /* barely/highly compressible */
+                    buffNb = tnb[buffNb >> 3];
+                } else {
+                    const U32 tnb[2] = { 0, 4 };   /* not compressible / sparse */
+                    buffNb = tnb[buffNb >> 3];
+            }   }
+            srcBuffer = cNoiseBuffer[buffNb];
+        }
+
+        /* select src segment */
+        sampleSize = FUZ_randomLength(&lseed, maxSampleLog);
+
+        /* create sample buffer (to catch read error with valgrind & sanitizers)  */
+        sampleBuffer = (BYTE*)malloc(sampleSize);
+        CHECK(sampleBuffer==NULL, "not enough memory for sample buffer");
+        { size_t const sampleStart = FUZ_rand(&lseed) % (srcBufferSize - sampleSize);
+          memcpy(sampleBuffer, srcBuffer + sampleStart, sampleSize); }
+        crcOrig = XXH64(sampleBuffer, sampleSize, 0);
+
+        /* compression tests */
+        {   int const cLevelPositive = (int)
+                    ( FUZ_rand(&lseed) %
+                     ((U32)ZSTD_maxCLevel() - (FUZ_highbit32((U32)sampleSize) / (U32)cLevelLimiter)) )
+                    + 1;
+            int const cLevel = ((FUZ_rand(&lseed) & 15) == 3) ?
+                             - (int)((FUZ_rand(&lseed) & 7) + 1) :   /* test negative cLevel */
+                             cLevelPositive;
+            DISPLAYLEVEL(5, "fuzzer t%u: Simple compression test (level %i) \n", testNb, cLevel);
+            cSize = ZSTD_compressCCtx(ctx, cBuffer, cBufferSize, sampleBuffer, sampleSize, cLevel);
+            CHECK(ZSTD_isError(cSize), "ZSTD_compressCCtx failed : %s", ZSTD_getErrorName(cSize));
+
+            /* compression failure test : too small dest buffer */
+            assert(cSize > 3);
+            {   const size_t missing = (FUZ_rand(&lseed) % (cSize-2)) + 1;
+                const size_t tooSmallSize = cSize - missing;
+                const unsigned endMark = 0x4DC2B1A9;
+                memcpy(dstBuffer+tooSmallSize, &endMark, sizeof(endMark));
+                DISPLAYLEVEL(5, "fuzzer t%u: compress into too small buffer of size %u (missing %u bytes) \n",
+                            testNb, (unsigned)tooSmallSize, (unsigned)missing);
+                { size_t const errorCode = ZSTD_compressCCtx(ctx, dstBuffer, tooSmallSize, sampleBuffer, sampleSize, cLevel);
+                  CHECK(!ZSTD_isError(errorCode), "ZSTD_compressCCtx should have failed ! (buffer too small : %u < %u)", (unsigned)tooSmallSize, (unsigned)cSize); }
+                { unsigned endCheck; memcpy(&endCheck, dstBuffer+tooSmallSize, sizeof(endCheck));
+                  CHECK(endCheck != endMark, "ZSTD_compressCCtx : dst buffer overflow  (check.%08X != %08X.mark)", endCheck, endMark); }
+        }   }
+
+        /* frame header decompression test */
+        {   ZSTD_frameHeader zfh;
+            CHECK_Z( ZSTD_getFrameHeader(&zfh, cBuffer, cSize) );
+            CHECK(zfh.frameContentSize != sampleSize, "Frame content size incorrect");
+        }
+
+        /* Decompressed size test */
+        {   unsigned long long const rSize = ZSTD_findDecompressedSize(cBuffer, cSize);
+            CHECK(rSize != sampleSize, "decompressed size incorrect");
+        }
+
+        /* successful decompression test */
+        DISPLAYLEVEL(5, "fuzzer t%u: simple decompression test \n", testNb);
+        {   size_t const margin = (FUZ_rand(&lseed) & 1) ? 0 : (FUZ_rand(&lseed) & 31) + 1;
+            size_t const dSize = ZSTD_decompress(dstBuffer, sampleSize + margin, cBuffer, cSize);
+            CHECK(dSize != sampleSize, "ZSTD_decompress failed (%s) (srcSize : %u ; cSize : %u)", ZSTD_getErrorName(dSize), (unsigned)sampleSize, (unsigned)cSize);
+            {   U64 const crcDest = XXH64(dstBuffer, sampleSize, 0);
+                CHECK(crcOrig != crcDest, "decompression result corrupted (pos %u / %u)", (unsigned)findDiff(sampleBuffer, dstBuffer, sampleSize), (unsigned)sampleSize);
+        }   }
+
+        free(sampleBuffer);   /* no longer useful after this point */
+
+        /* truncated src decompression test */
+        DISPLAYLEVEL(5, "fuzzer t%u: decompression of truncated source \n", testNb);
+        {   size_t const missing = (FUZ_rand(&lseed) % (cSize-2)) + 1;   /* no problem, as cSize > 4 (frameHeaderSizer) */
+            size_t const tooSmallSize = cSize - missing;
+            void* cBufferTooSmall = malloc(tooSmallSize);   /* valgrind will catch read overflows */
+            CHECK(cBufferTooSmall == NULL, "not enough memory !");
+            memcpy(cBufferTooSmall, cBuffer, tooSmallSize);
+            { size_t const errorCode = ZSTD_decompress(dstBuffer, dstBufferSize, cBufferTooSmall, tooSmallSize);
+              CHECK(!ZSTD_isError(errorCode), "ZSTD_decompress should have failed ! (truncated src buffer)"); }
+            free(cBufferTooSmall);
+        }
+
+        /* too small dst decompression test */
+        DISPLAYLEVEL(5, "fuzzer t%u: decompress into too small dst buffer \n", testNb);
+        if (sampleSize > 3) {
+            size_t const missing = (FUZ_rand(&lseed) % (sampleSize-2)) + 1;   /* no problem, as cSize > 4 (frameHeaderSizer) */
+            size_t const tooSmallSize = sampleSize - missing;
+            static const BYTE token = 0xA9;
+            dstBuffer[tooSmallSize] = token;
+            { size_t const errorCode = ZSTD_decompress(dstBuffer, tooSmallSize, cBuffer, cSize);
+              CHECK(!ZSTD_isError(errorCode), "ZSTD_decompress should have failed : %u > %u (dst buffer too small)", (unsigned)errorCode, (unsigned)tooSmallSize); }
+            CHECK(dstBuffer[tooSmallSize] != token, "ZSTD_decompress : dst buffer overflow");
+        }
+
+        /* noisy src decompression test */
+        if (cSize > 6) {
+            /* insert noise into src */
+            {   U32 const maxNbBits = FUZ_highbit32((U32)(cSize-4));
+                size_t pos = 4;   /* preserve magic number (too easy to detect) */
+                for (;;) {
+                    /* keep some original src */
+                    {   U32 const nbBits = FUZ_rand(&lseed) % maxNbBits;
+                        size_t const mask = (1<<nbBits) - 1;
+                        size_t const skipLength = FUZ_rand(&lseed) & mask;
+                        pos += skipLength;
+                    }
+                    if (pos >= cSize) break;
+                    /* add noise */
+                    {   U32 const nbBitsCodes = FUZ_rand(&lseed) % maxNbBits;
+                        U32 const nbBits = nbBitsCodes ? nbBitsCodes-1 : 0;
+                        size_t const mask = (1<<nbBits) - 1;
+                        size_t const rNoiseLength = (FUZ_rand(&lseed) & mask) + 1;
+                        size_t const noiseLength = MIN(rNoiseLength, cSize-pos);
+                        size_t const noiseStart = FUZ_rand(&lseed) % (srcBufferSize - noiseLength);
+                        memcpy(cBuffer + pos, srcBuffer + noiseStart, noiseLength);
+                        pos += noiseLength;
+            }   }   }
+
+            /* decompress noisy source */
+            DISPLAYLEVEL(5, "fuzzer t%u: decompress noisy source \n", testNb);
+            {   U32 const endMark = 0xA9B1C3D6;
+                memcpy(dstBuffer+sampleSize, &endMark, 4);
+                {   size_t const decompressResult = ZSTD_decompress(dstBuffer, sampleSize, cBuffer, cSize);
+                    /* result *may* be an unlikely success, but even then, it must strictly respect dst buffer boundaries */
+                    CHECK((!ZSTD_isError(decompressResult)) && (decompressResult>sampleSize),
+                          "ZSTD_decompress on noisy src : result is too large : %u > %u (dst buffer)", (unsigned)decompressResult, (unsigned)sampleSize);
+                }
+                {   U32 endCheck; memcpy(&endCheck, dstBuffer+sampleSize, 4);
+                    CHECK(endMark!=endCheck, "ZSTD_decompress on noisy src : dst buffer overflow");
+        }   }   }   /* noisy src decompression test */
+
+        /*=====   Bufferless streaming compression test, scattered segments and dictionary   =====*/
+        DISPLAYLEVEL(5, "fuzzer t%u: Bufferless streaming compression test \n", testNb);
+        {   U32 const testLog = FUZ_rand(&lseed) % maxSrcLog;
+            U32 const dictLog = FUZ_rand(&lseed) % maxSrcLog;
+            int const cLevel = (FUZ_rand(&lseed) %
+                                (ZSTD_maxCLevel() -
+                                 (MAX(testLog, dictLog) / cLevelLimiter))) +
+                               1;
+            maxTestSize = FUZ_rLogLength(&lseed, testLog);
+            if (maxTestSize >= dstBufferSize) maxTestSize = dstBufferSize-1;
+
+            dictSize = FUZ_rLogLength(&lseed, dictLog);   /* needed also for decompression */
+            dict = srcBuffer + (FUZ_rand(&lseed) % (srcBufferSize - dictSize));
+
+            DISPLAYLEVEL(6, "fuzzer t%u: Compressing up to <=%u bytes at level %i with dictionary size %u \n",
+                            testNb, (unsigned)maxTestSize, cLevel, (unsigned)dictSize);
+
+            if (FUZ_rand(&lseed) & 0xF) {
+                CHECK_Z ( ZSTD_compressBegin_usingDict(refCtx, dict, dictSize, cLevel) );
+            } else {
+                ZSTD_compressionParameters const cPar = ZSTD_getCParams(cLevel, ZSTD_CONTENTSIZE_UNKNOWN, dictSize);
+                ZSTD_frameParameters const fPar = { FUZ_rand(&lseed)&1 /* contentSizeFlag */,
+                                                    !(FUZ_rand(&lseed)&3) /* contentChecksumFlag*/,
+                                                    0 /*NodictID*/ };   /* note : since dictionary is fake, dictIDflag has no impact */
+                ZSTD_parameters const p = FUZ_makeParams(cPar, fPar);
+                CHECK_Z ( ZSTD_compressBegin_advanced(refCtx, dict, dictSize, p, 0) );
+            }
+            CHECK_Z( ZSTD_copyCCtx(ctx, refCtx, 0) );
+        }
+
+        {   U32 const nbChunks = (FUZ_rand(&lseed) & 127) + 2;
+            U32 n;
+            XXH64_state_t xxhState;
+            XXH64_reset(&xxhState, 0);
+            for (totalTestSize=0, cSize=0, n=0 ; n<nbChunks ; n++) {
+                size_t const segmentSize = FUZ_randomLength(&lseed, maxSampleLog);
+                size_t const segmentStart = FUZ_rand(&lseed) % (srcBufferSize - segmentSize);
+
+                if (cBufferSize-cSize < ZSTD_compressBound(segmentSize)) break;   /* avoid invalid dstBufferTooSmall */
+                if (totalTestSize+segmentSize > maxTestSize) break;
+
+                {   size_t const compressResult = ZSTD_compressContinue(ctx, cBuffer+cSize, cBufferSize-cSize, srcBuffer+segmentStart, segmentSize);
+                    CHECK (ZSTD_isError(compressResult), "multi-segments compression error : %s", ZSTD_getErrorName(compressResult));
+                    cSize += compressResult;
+                }
+                XXH64_update(&xxhState, srcBuffer+segmentStart, segmentSize);
+                memcpy(mirrorBuffer + totalTestSize, srcBuffer+segmentStart, segmentSize);
+                totalTestSize += segmentSize;
+            }
+
+            {   size_t const flushResult = ZSTD_compressEnd(ctx, cBuffer+cSize, cBufferSize-cSize, NULL, 0);
+                CHECK (ZSTD_isError(flushResult), "multi-segments epilogue error : %s", ZSTD_getErrorName(flushResult));
+                cSize += flushResult;
+            }
+            crcOrig = XXH64_digest(&xxhState);
+        }
+
+        /* streaming decompression test */
+        DISPLAYLEVEL(5, "fuzzer t%u: Bufferless streaming decompression test \n", testNb);
+        /* ensure memory requirement is good enough (should always be true) */
+        {   ZSTD_frameHeader zfh;
+            CHECK( ZSTD_getFrameHeader(&zfh, cBuffer, ZSTD_FRAMEHEADERSIZE_MAX),
+                  "ZSTD_getFrameHeader(): error retrieving frame information");
+            {   size_t const roundBuffSize = ZSTD_decodingBufferSize_min(zfh.windowSize, zfh.frameContentSize);
+                CHECK_Z(roundBuffSize);
+                CHECK((roundBuffSize > totalTestSize) && (zfh.frameContentSize!=ZSTD_CONTENTSIZE_UNKNOWN),
+                      "ZSTD_decodingBufferSize_min() requires more memory (%u) than necessary (%u)",
+                      (unsigned)roundBuffSize, (unsigned)totalTestSize );
+        }   }
+        if (dictSize<8) dictSize=0, dict=NULL;   /* disable dictionary */
+        CHECK_Z( ZSTD_decompressBegin_usingDict(dctx, dict, dictSize) );
+        totalCSize = 0;
+        totalGenSize = 0;
+        while (totalCSize < cSize) {
+            size_t const inSize = ZSTD_nextSrcSizeToDecompress(dctx);
+            size_t const genSize = ZSTD_decompressContinue(dctx, dstBuffer+totalGenSize, dstBufferSize-totalGenSize, cBuffer+totalCSize, inSize);
+            CHECK (ZSTD_isError(genSize), "ZSTD_decompressContinue error : %s", ZSTD_getErrorName(genSize));
+            totalGenSize += genSize;
+            totalCSize += inSize;
+        }
+        CHECK (ZSTD_nextSrcSizeToDecompress(dctx) != 0, "frame not fully decoded");
+        CHECK (totalGenSize != totalTestSize, "streaming decompressed data : wrong size")
+        CHECK (totalCSize != cSize, "compressed data should be fully read")
+        {   U64 const crcDest = XXH64(dstBuffer, totalTestSize, 0);
+            CHECK(crcOrig != crcDest, "streaming decompressed data corrupted (pos %u / %u)",
+                (unsigned)findDiff(mirrorBuffer, dstBuffer, totalTestSize), (unsigned)totalTestSize);
+        }
+    }   /* for ( ; (testNb <= nbTests) */
+    DISPLAY("\r%u fuzzer tests completed   \n", testNb-1);
+
+_cleanup:
+    ZSTD_freeCCtx(refCtx);
+    ZSTD_freeCCtx(ctx);
+    ZSTD_freeDCtx(dctx);
+    free(cNoiseBuffer[0]);
+    free(cNoiseBuffer[1]);
+    free(cNoiseBuffer[2]);
+    free(cNoiseBuffer[3]);
+    free(cNoiseBuffer[4]);
+    free(cBuffer);
+    free(dstBuffer);
+    free(mirrorBuffer);
+    return result;
+
+_output_error:
+    result = 1;
+    goto _cleanup;
+}
+
+
+/*_*******************************************************
+*  Command line
+*********************************************************/
+static int FUZ_usage(const char* programName)
+{
+    DISPLAY( "Usage :\n");
+    DISPLAY( "      %s [args]\n", programName);
+    DISPLAY( "\n");
+    DISPLAY( "Arguments :\n");
+    DISPLAY( " -i#    : Number of tests (default:%i)\n", nbTestsDefault);
+    DISPLAY( " -T#    : Max duration to run for. Overrides number of tests. (e.g. -T1m or -T60s for one minute)\n");
+    DISPLAY( " -s#    : Select seed (default:prompt user)\n");
+    DISPLAY( " -t#    : Select starting test number (default:0)\n");
+    DISPLAY( " -P#    : Select compressibility in %% (default:%i%%)\n", FUZ_compressibility_default);
+    DISPLAY( " -v     : verbose\n");
+    DISPLAY( " -p     : pause at the end\n");
+    DISPLAY( " -h     : display help and exit\n");
+    return 0;
+}
+
+/*! readU32FromChar() :
+    @return : unsigned integer value read from input in `char` format
+    allows and interprets K, KB, KiB, M, MB and MiB suffix.
+    Will also modify `*stringPtr`, advancing it to position where it stopped reading.
+    Note : function result can overflow if digit string > MAX_UINT */
+static unsigned readU32FromChar(const char** stringPtr)
+{
+    unsigned result = 0;
+    while ((**stringPtr >='0') && (**stringPtr <='9'))
+        result *= 10, result += **stringPtr - '0', (*stringPtr)++ ;
+    if ((**stringPtr=='K') || (**stringPtr=='M')) {
+        result <<= 10;
+        if (**stringPtr=='M') result <<= 10;
+        (*stringPtr)++ ;
+        if (**stringPtr=='i') (*stringPtr)++;
+        if (**stringPtr=='B') (*stringPtr)++;
+    }
+    return result;
+}
+
+/** longCommandWArg() :
+ *  check if *stringPtr is the same as longCommand.
+ *  If yes, @return 1 and advances *stringPtr to the position which immediately follows longCommand.
+ *  @return 0 and doesn't modify *stringPtr otherwise.
+ */
+static int longCommandWArg(const char** stringPtr, const char* longCommand)
+{
+    size_t const comSize = strlen(longCommand);
+    int const result = !strncmp(*stringPtr, longCommand, comSize);
+    if (result) *stringPtr += comSize;
+    return result;
+}
+
+int main(int argc, const char** argv)
+{
+    U32 seed = 0;
+    int seedset = 0;
+    int argNb;
+    int nbTests = nbTestsDefault;
+    int testNb = 0;
+    int proba = FUZ_compressibility_default;
+    int result = 0;
+    U32 mainPause = 0;
+    U32 maxDuration = 0;
+    int bigTests = 1;
+    U32 memTestsOnly = 0;
+    const char* const programName = argv[0];
+
+    /* Check command line */
+    for (argNb=1; argNb<argc; argNb++) {
+        const char* argument = argv[argNb];
+        if(!argument) continue;   /* Protection if argument empty */
+
+        /* Handle commands. Aggregated commands are allowed */
+        if (argument[0]=='-') {
+
+            if (longCommandWArg(&argument, "--memtest=")) { memTestsOnly = readU32FromChar(&argument); continue; }
+
+            if (!strcmp(argument, "--memtest")) { memTestsOnly=1; continue; }
+            if (!strcmp(argument, "--no-big-tests")) { bigTests=0; continue; }
+
+            argument++;
+            while (*argument!=0) {
+                switch(*argument)
+                {
+                case 'h':
+                    return FUZ_usage(programName);
+
+                case 'v':
+                    argument++;
+                    g_displayLevel++;
+                    break;
+
+                case 'q':
+                    argument++;
+                    g_displayLevel--;
+                    break;
+
+                case 'p': /* pause at the end */
+                    argument++;
+                    mainPause = 1;
+                    break;
+
+                case 'i':
+                    argument++; maxDuration = 0;
+                    nbTests = (int)readU32FromChar(&argument);
+                    break;
+
+                case 'T':
+                    argument++;
+                    nbTests = 0;
+                    maxDuration = readU32FromChar(&argument);
+                    if (*argument=='s') argument++;   /* seconds */
+                    if (*argument=='m') maxDuration *= 60, argument++;   /* minutes */
+                    if (*argument=='n') argument++;
+                    break;
+
+                case 's':
+                    argument++;
+                    seedset = 1;
+                    seed = readU32FromChar(&argument);
+                    break;
+
+                case 't':
+                    argument++;
+                    testNb = (int)readU32FromChar(&argument);
+                    break;
+
+                case 'P':   /* compressibility % */
+                    argument++;
+                    proba = (int)readU32FromChar(&argument);
+                    if (proba>100) proba = 100;
+                    break;
+
+                default:
+                    return (FUZ_usage(programName), 1);
+    }   }   }   }   /* for (argNb=1; argNb<argc; argNb++) */
+
+    /* Get Seed */
+    DISPLAY("Starting zstd tester (%i-bits, %s)\n", (int)(sizeof(size_t)*8), ZSTD_VERSION_STRING);
+
+    if (!seedset) {
+        time_t const t = time(NULL);
+        U32 const h = XXH32(&t, sizeof(t), 1);
+        seed = h % 10000;
+    }
+
+    DISPLAY("Seed = %u\n", (unsigned)seed);
+    if (proba!=FUZ_compressibility_default) DISPLAY("Compressibility : %i%%\n", proba);
+
+    if (memTestsOnly) {
+        g_displayLevel = MAX(3, g_displayLevel);
+        return FUZ_mallocTests(seed, ((double)proba) / 100, memTestsOnly);
+    }
+
+    if (nbTests < testNb) nbTests = testNb;
+
+    if (testNb==0)
+        result = basicUnitTests(0, ((double)proba) / 100);  /* constant seed for predictability */
+    if (!result)
+        result = fuzzerTests(seed, nbTests, testNb, maxDuration, ((double)proba) / 100, bigTests);
+    if (mainPause) {
+        int unused;
+        DISPLAY("Press Enter \n");
+        unused = getchar();
+        (void)unused;
+    }
+    return result;
+}