Adding upstream version 15.4.upstream/15.4upstream

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

1 files changed, 170 insertions, 0 deletions

diff --git a/src/tools/testint128.c b/src/tools/testint128.c
new file mode 100644
index 0000000..2ebd4f5
--- /dev/null
+++ b/src/tools/testint128.c
@@ -0,0 +1,170 @@
+/*-------------------------------------------------------------------------
+ *
+ * testint128.c
+ *	  Testbed for roll-our-own 128-bit integer arithmetic.
+ *
+ * This is a standalone test program that compares the behavior of an
+ * implementation in int128.h to an (assumed correct) int128 native type.
+ *
+ * Copyright (c) 2017-2022, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  src/tools/testint128.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres_fe.h"
+
+/*
+ * By default, we test the non-native implementation in int128.h; but
+ * by predefining USE_NATIVE_INT128 to 1, you can test the native
+ * implementation, just to be sure.
+ */
+#ifndef USE_NATIVE_INT128
+#define USE_NATIVE_INT128 0
+#endif
+
+#include "common/int128.h"
+#include "common/pg_prng.h"
+
+/*
+ * We assume the parts of this union are laid out compatibly.
+ */
+typedef union
+{
+	int128		i128;
+	INT128		I128;
+	union
+	{
+#ifdef WORDS_BIGENDIAN
+		int64		hi;
+		uint64		lo;
+#else
+		uint64		lo;
+		int64		hi;
+#endif
+	}			hl;
+}			test128;
+
+
+/*
+ * Control version of comparator.
+ */
+static inline int
+my_int128_compare(int128 x, int128 y)
+{
+	if (x < y)
+		return -1;
+	if (x > y)
+		return 1;
+	return 0;
+}
+
+/*
+ * Main program.
+ *
+ * Generates a lot of random numbers and tests the implementation for each.
+ * The results should be reproducible, since we use a fixed PRNG seed.
+ *
+ * You can give a loop count if you don't like the default 1B iterations.
+ */
+int
+main(int argc, char **argv)
+{
+	long		count;
+
+	pg_prng_seed(&pg_global_prng_state, 0);
+
+	if (argc >= 2)
+		count = strtol(argv[1], NULL, 0);
+	else
+		count = 1000000000;
+
+	while (count-- > 0)
+	{
+		int64		x = pg_prng_uint64(&pg_global_prng_state);
+		int64		y = pg_prng_uint64(&pg_global_prng_state);
+		int64		z = pg_prng_uint64(&pg_global_prng_state);
+		test128		t1;
+		test128		t2;
+
+		/* check unsigned addition */
+		t1.hl.hi = x;
+		t1.hl.lo = y;
+		t2 = t1;
+		t1.i128 += (int128) (uint64) z;
+		int128_add_uint64(&t2.I128, (uint64) z);
+
+		if (t1.hl.hi != t2.hl.hi || t1.hl.lo != t2.hl.lo)
+		{
+			printf("%016lX%016lX + unsigned %lX\n", x, y, z);
+			printf("native = %016lX%016lX\n", t1.hl.hi, t1.hl.lo);
+			printf("result = %016lX%016lX\n", t2.hl.hi, t2.hl.lo);
+			return 1;
+		}
+
+		/* check signed addition */
+		t1.hl.hi = x;
+		t1.hl.lo = y;
+		t2 = t1;
+		t1.i128 += (int128) z;
+		int128_add_int64(&t2.I128, z);
+
+		if (t1.hl.hi != t2.hl.hi || t1.hl.lo != t2.hl.lo)
+		{
+			printf("%016lX%016lX + signed %lX\n", x, y, z);
+			printf("native = %016lX%016lX\n", t1.hl.hi, t1.hl.lo);
+			printf("result = %016lX%016lX\n", t2.hl.hi, t2.hl.lo);
+			return 1;
+		}
+
+		/* check multiplication */
+		t1.i128 = (int128) x * (int128) y;
+
+		t2.hl.hi = t2.hl.lo = 0;
+		int128_add_int64_mul_int64(&t2.I128, x, y);
+
+		if (t1.hl.hi != t2.hl.hi || t1.hl.lo != t2.hl.lo)
+		{
+			printf("%lX * %lX\n", x, y);
+			printf("native = %016lX%016lX\n", t1.hl.hi, t1.hl.lo);
+			printf("result = %016lX%016lX\n", t2.hl.hi, t2.hl.lo);
+			return 1;
+		}
+
+		/* check comparison */
+		t1.hl.hi = x;
+		t1.hl.lo = y;
+		t2.hl.hi = z;
+		t2.hl.lo = pg_prng_uint64(&pg_global_prng_state);
+
+		if (my_int128_compare(t1.i128, t2.i128) !=
+			int128_compare(t1.I128, t2.I128))
+		{
+			printf("comparison failure: %d vs %d\n",
+				   my_int128_compare(t1.i128, t2.i128),
+				   int128_compare(t1.I128, t2.I128));
+			printf("arg1 = %016lX%016lX\n", t1.hl.hi, t1.hl.lo);
+			printf("arg2 = %016lX%016lX\n", t2.hl.hi, t2.hl.lo);
+			return 1;
+		}
+
+		/* check case with identical hi parts; above will hardly ever hit it */
+		t2.hl.hi = x;
+
+		if (my_int128_compare(t1.i128, t2.i128) !=
+			int128_compare(t1.I128, t2.I128))
+		{
+			printf("comparison failure: %d vs %d\n",
+				   my_int128_compare(t1.i128, t2.i128),
+				   int128_compare(t1.I128, t2.I128));
+			printf("arg1 = %016lX%016lX\n", t1.hl.hi, t1.hl.lo);
+			printf("arg2 = %016lX%016lX\n", t2.hl.hi, t2.hl.lo);
+			return 1;
+		}
+	}
+
+	return 0;
+}