1 files changed, 113 insertions, 0 deletions
diff --git a/js/src/ds/Bitmap.cpp b/js/src/ds/Bitmap.cpp
new file mode 100644
index 0000000000..d96cf67c71
--- /dev/null
+++ b/js/src/ds/Bitmap.cpp
@@ -0,0 +1,113 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ds/Bitmap.h"
+
+#include <algorithm>
+
+#include "js/UniquePtr.h"
+
+using namespace js;
+
+SparseBitmap::~SparseBitmap() {
+  for (Data::Range r(data.all()); !r.empty(); r.popFront()) {
+    js_delete(r.front().value());
+  }
+}
+
+size_t SparseBitmap::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) {
+  size_t size = data.shallowSizeOfExcludingThis(mallocSizeOf);
+  for (Data::Range r(data.all()); !r.empty(); r.popFront()) {
+    size += mallocSizeOf(r.front().value());
+  }
+  return size;
+}
+
+SparseBitmap::BitBlock* SparseBitmap::createBlock(Data::AddPtr p,
+                                                  size_t blockId) {
+  MOZ_ASSERT(!p);
+  auto block = js::MakeUnique<BitBlock>();
+  if (!block || !data.add(p, blockId, block.get())) {
+    return nullptr;
+  }
+  std::fill(block->begin(), block->end(), 0);
+  return block.release();
+}
+
+SparseBitmap::BitBlock& SparseBitmap::createBlock(
+    Data::AddPtr p, size_t blockId, AutoEnterOOMUnsafeRegion& oomUnsafe) {
+  BitBlock* block = createBlock(p, blockId);
+  if (!block) {
+    oomUnsafe.crash("Bitmap OOM");
+  }
+  return *block;
+}
+
+bool SparseBitmap::getBit(size_t bit) const {
+  size_t word = bit / JS_BITS_PER_WORD;
+  size_t blockWord = blockStartWord(word);
+
+  const BitBlock* block = getBlock(blockWord / WordsInBlock);
+  if (block) {
+    return (*block)[word - blockWord] & bitMask(bit);
+  }
+  return false;
+}
+
+bool SparseBitmap::readonlyThreadsafeGetBit(size_t bit) const {
+  size_t word = bit / JS_BITS_PER_WORD;
+  size_t blockWord = blockStartWord(word);
+
+  const BitBlock* block = readonlyThreadsafeGetBlock(blockWord / WordsInBlock);
+  if (block) {
+    return (*block)[word - blockWord] & bitMask(bit);
+  }
+  return false;
+}
+
+void SparseBitmap::bitwiseAndWith(const DenseBitmap& other) {
+  for (Data::Enum e(data); !e.empty(); e.popFront()) {
+    BitBlock& block = *e.front().value();
+    size_t blockWord = e.front().key() * WordsInBlock;
+    bool anySet = false;
+    size_t numWords = wordIntersectCount(blockWord, other);
+    for (size_t i = 0; i < numWords; i++) {
+      block[i] &= other.word(blockWord + i);
+      anySet |= !!block[i];
+    }
+    if (!anySet) {
+      js_delete(&block);
+      e.removeFront();
+    }
+  }
+}
+
+void SparseBitmap::bitwiseOrWith(const SparseBitmap& other) {
+  for (Data::Range r(other.data.all()); !r.empty(); r.popFront()) {
+    const BitBlock& otherBlock = *r.front().value();
+    BitBlock& block = getOrCreateBlock(r.front().key());
+    for (size_t i = 0; i < WordsInBlock; i++) {
+      block[i] |= otherBlock[i];
+    }
+  }
+}
+
+void SparseBitmap::bitwiseOrInto(DenseBitmap& other) const {
+  for (Data::Range r(data.all()); !r.empty(); r.popFront()) {
+    BitBlock& block = *r.front().value();
+    size_t blockWord = r.front().key() * WordsInBlock;
+    size_t numWords = wordIntersectCount(blockWord, other);
+#ifdef DEBUG
+    // Any words out of range in other should be zero in this bitmap.
+    for (size_t i = numWords; i < WordsInBlock; i++) {
+      MOZ_ASSERT(!block[i]);
+    }
+#endif
+    for (size_t i = 0; i < numWords; i++) {
+      other.word(blockWord + i) |= block[i];
+    }
+  }
+}