diff -r 000000000000 -r 6474c204b198 js/src/jit/shared/Assembler-x86-shared.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit/shared/Assembler-x86-shared.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,133 @@
+/* -*- 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 "gc/Marking.h"
+#include "jit/JitCompartment.h"
+#if defined(JS_CODEGEN_X86)
+# include "jit/x86/MacroAssembler-x86.h"
+#elif defined(JS_CODEGEN_X64)
+# include "jit/x64/MacroAssembler-x64.h"
+#else
+# error "Wrong architecture. Only x86 and x64 should build this file!"
+#endif
+
+using namespace js;
+using namespace js::jit;
+
+void
+AssemblerX86Shared::copyJumpRelocationTable(uint8_t *dest)
+{
+    if (jumpRelocations_.length())
+        memcpy(dest, jumpRelocations_.buffer(), jumpRelocations_.length());
+}
+
+void
+AssemblerX86Shared::copyDataRelocationTable(uint8_t *dest)
+{
+    if (dataRelocations_.length())
+        memcpy(dest, dataRelocations_.buffer(), dataRelocations_.length());
+}
+
+void
+AssemblerX86Shared::copyPreBarrierTable(uint8_t *dest)
+{
+    if (preBarriers_.length())
+        memcpy(dest, preBarriers_.buffer(), preBarriers_.length());
+}
+
+static void
+TraceDataRelocations(JSTracer *trc, uint8_t *buffer, CompactBufferReader &reader)
+{
+    while (reader.more()) {
+        size_t offset = reader.readUnsigned();
+        void **ptr = JSC::X86Assembler::getPointerRef(buffer + offset);
+
+#ifdef JS_PUNBOX64
+        // All pointers on x64 will have the top bits cleared. If those bits
+        // are not cleared, this must be a Value.
+        uintptr_t *word = reinterpret_cast<uintptr_t *>(ptr);
+        if (*word >> JSVAL_TAG_SHIFT) {
+            jsval_layout layout;
+            layout.asBits = *word;
+            Value v = IMPL_TO_JSVAL(layout);
+            gc::MarkValueUnbarriered(trc, &v, "ion-masm-value");
+            JS_ASSERT(*word == JSVAL_TO_IMPL(v).asBits);
+            continue;
+        }
+#endif
+
+        // No barrier needed since these are constants.
+        gc::MarkGCThingUnbarriered(trc, reinterpret_cast<void **>(ptr), "ion-masm-ptr");
+    }
+}
+
+
+void
+AssemblerX86Shared::TraceDataRelocations(JSTracer *trc, JitCode *code, CompactBufferReader &reader)
+{
+    ::TraceDataRelocations(trc, code->raw(), reader);
+}
+
+void
+AssemblerX86Shared::trace(JSTracer *trc)
+{
+    for (size_t i = 0; i < jumps_.length(); i++) {
+        RelativePatch &rp = jumps_[i];
+        if (rp.kind == Relocation::JITCODE) {
+            JitCode *code = JitCode::FromExecutable((uint8_t *)rp.target);
+            MarkJitCodeUnbarriered(trc, &code, "masmrel32");
+            JS_ASSERT(code == JitCode::FromExecutable((uint8_t *)rp.target));
+        }
+    }
+    if (dataRelocations_.length()) {
+        CompactBufferReader reader(dataRelocations_);
+        ::TraceDataRelocations(trc, masm.buffer(), reader);
+    }
+}
+
+void
+AssemblerX86Shared::executableCopy(void *buffer)
+{
+    masm.executableCopy(buffer);
+}
+
+void
+AssemblerX86Shared::processCodeLabels(uint8_t *rawCode)
+{
+    for (size_t i = 0; i < codeLabels_.length(); i++) {
+        CodeLabel label = codeLabels_[i];
+        Bind(rawCode, label.dest(), rawCode + label.src()->offset());
+    }
+}
+
+AssemblerX86Shared::Condition
+AssemblerX86Shared::InvertCondition(Condition cond)
+{
+    switch (cond) {
+      case Zero:
+        return NonZero;
+      case NonZero:
+        return Zero;
+      case LessThan:
+        return GreaterThanOrEqual;
+      case LessThanOrEqual:
+        return GreaterThan;
+      case GreaterThan:
+        return LessThanOrEqual;
+      case GreaterThanOrEqual:
+        return LessThan;
+      case Above:
+        return BelowOrEqual;
+      case AboveOrEqual:
+        return Below;
+      case Below:
+        return AboveOrEqual;
+      case BelowOrEqual:
+        return Above;
+      default:
+        MOZ_ASSUME_UNREACHABLE("unexpected condition");
+    }
+}