diff -r 000000000000 -r 6474c204b198 js/src/jit/BitSet.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit/BitSet.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,124 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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 "jit/BitSet.h"
+
+using namespace js;
+using namespace js::jit;
+
+BitSet *
+BitSet::New(TempAllocator &alloc, unsigned int numBits)
+{
+    BitSet *result = new(alloc) BitSet(numBits);
+    if (!result->init(alloc))
+        return nullptr;
+    return result;
+}
+
+bool
+BitSet::init(TempAllocator &alloc)
+{
+    size_t sizeRequired = numWords() * sizeof(*bits_);
+
+    bits_ = (uint32_t *)alloc.allocate(sizeRequired);
+    if (!bits_)
+        return false;
+
+    memset(bits_, 0, sizeRequired);
+
+    return true;
+}
+
+bool
+BitSet::empty() const
+{
+    JS_ASSERT(bits_);
+    const uint32_t *bits = bits_;
+    for (unsigned int i = 0, e = numWords(); i < e; i++) {
+        if (bits[i])
+            return false;
+    }
+    return true;
+}
+
+void
+BitSet::insertAll(const BitSet *other)
+{
+    JS_ASSERT(bits_);
+    JS_ASSERT(other->numBits_ == numBits_);
+    JS_ASSERT(other->bits_);
+
+    uint32_t *bits = bits_;
+    const uint32_t *otherBits = other->bits_;
+    for (unsigned int i = 0, e = numWords(); i < e; i++)
+        bits[i] |= otherBits[i];
+}
+
+void
+BitSet::removeAll(const BitSet *other)
+{
+    JS_ASSERT(bits_);
+    JS_ASSERT(other->numBits_ == numBits_);
+    JS_ASSERT(other->bits_);
+
+    uint32_t *bits = bits_;
+    const uint32_t *otherBits = other->bits_;
+    for (unsigned int i = 0, e = numWords(); i < e; i++)
+        bits[i] &= ~otherBits[i];
+}
+
+void
+BitSet::intersect(const BitSet *other)
+{
+    JS_ASSERT(bits_);
+    JS_ASSERT(other->numBits_ == numBits_);
+    JS_ASSERT(other->bits_);
+
+    uint32_t *bits = bits_;
+    const uint32_t *otherBits = other->bits_;
+    for (unsigned int i = 0, e = numWords(); i < e; i++)
+        bits[i] &= otherBits[i];
+}
+
+// returns true if the intersection caused the contents of the set to change.
+bool
+BitSet::fixedPointIntersect(const BitSet *other)
+{
+    JS_ASSERT(bits_);
+    JS_ASSERT(other->numBits_ == numBits_);
+    JS_ASSERT(other->bits_);
+
+    bool changed = false;
+
+    uint32_t *bits = bits_;
+    const uint32_t *otherBits = other->bits_;
+    for (unsigned int i = 0, e = numWords(); i < e; i++) {
+        uint32_t old = bits[i];
+        bits[i] &= otherBits[i];
+
+        if (!changed && old != bits[i])
+            changed = true;
+    }
+    return changed;
+}
+
+void
+BitSet::complement()
+{
+    JS_ASSERT(bits_);
+    uint32_t *bits = bits_;
+    for (unsigned int i = 0, e = numWords(); i < e; i++)
+        bits[i] = ~bits[i];
+}
+
+void
+BitSet::clear()
+{
+    JS_ASSERT(bits_);
+    uint32_t *bits = bits_;
+    for (unsigned int i = 0, e = numWords(); i < e; i++)
+        bits[i] = 0;
+}