diff -r 000000000000 -r 6474c204b198 js/src/jit/x86/Architecture-x86.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit/x86/Architecture-x86.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,145 @@
+/* -*- 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/. */
+
+#ifndef jit_x86_Architecture_x86_h
+#define jit_x86_Architecture_x86_h
+
+#include "assembler/assembler/MacroAssembler.h"
+
+namespace js {
+namespace jit {
+
+// In bytes: slots needed for potential memory->memory move spills.
+//   +8 for cycles
+//   +4 for gpr spills
+//   +8 for double spills
+static const uint32_t ION_FRAME_SLACK_SIZE    = 20;
+
+// Only Win64 requires shadow stack space.
+static const uint32_t ShadowStackSpace = 0;
+
+// These offsets are specific to nunboxing, and capture offsets into the
+// components of a js::Value.
+static const int32_t NUNBOX32_TYPE_OFFSET         = 4;
+static const int32_t NUNBOX32_PAYLOAD_OFFSET      = 0;
+
+////
+// These offsets are related to bailouts.
+////
+
+// Size of each bailout table entry. On x86 this is a 5-byte relative call.
+static const uint32_t BAILOUT_TABLE_ENTRY_SIZE    = 5;
+
+class Registers {
+  public:
+    typedef JSC::X86Registers::RegisterID Code;
+
+    static const char *GetName(Code code) {
+        static const char * const Names[] = { "eax", "ecx", "edx", "ebx",
+                                              "esp", "ebp", "esi", "edi" };
+        return Names[code];
+    }
+
+    static Code FromName(const char *name) {
+        for (size_t i = 0; i < Total; i++) {
+            if (strcmp(GetName(Code(i)), name) == 0)
+                return Code(i);
+        }
+        return Invalid;
+    }
+
+    static const Code StackPointer = JSC::X86Registers::esp;
+    static const Code Invalid = JSC::X86Registers::invalid_reg;
+
+    static const uint32_t Total = 8;
+    static const uint32_t Allocatable = 7;
+
+    static const uint32_t AllMask = (1 << Total) - 1;
+
+    static const uint32_t ArgRegMask = 0;
+
+    static const uint32_t VolatileMask =
+        (1 << JSC::X86Registers::eax) |
+        (1 << JSC::X86Registers::ecx) |
+        (1 << JSC::X86Registers::edx);
+
+    static const uint32_t NonVolatileMask =
+        (1 << JSC::X86Registers::ebx) |
+        (1 << JSC::X86Registers::esi) |
+        (1 << JSC::X86Registers::edi) |
+        (1 << JSC::X86Registers::ebp);
+
+    static const uint32_t WrapperMask =
+        VolatileMask |
+        (1 << JSC::X86Registers::ebx);
+
+    static const uint32_t SingleByteRegs =
+        (1 << JSC::X86Registers::eax) |
+        (1 << JSC::X86Registers::ecx) |
+        (1 << JSC::X86Registers::edx) |
+        (1 << JSC::X86Registers::ebx);
+
+    static const uint32_t NonAllocatableMask =
+        (1 << JSC::X86Registers::esp);
+
+    static const uint32_t AllocatableMask = AllMask & ~NonAllocatableMask;
+
+    // Registers that can be allocated without being saved, generally.
+    static const uint32_t TempMask = VolatileMask & ~NonAllocatableMask;
+
+    // Registers returned from a JS -> JS call.
+    static const uint32_t JSCallMask =
+        (1 << JSC::X86Registers::ecx) |
+        (1 << JSC::X86Registers::edx);
+
+    // Registers returned from a JS -> C call.
+    static const uint32_t CallMask =
+        (1 << JSC::X86Registers::eax);
+};
+
+// Smallest integer type that can hold a register bitmask.
+typedef uint8_t PackedRegisterMask;
+
+class FloatRegisters {
+  public:
+    typedef JSC::X86Registers::XMMRegisterID Code;
+
+    static const char *GetName(Code code) {
+        static const char * const Names[] = { "xmm0", "xmm1", "xmm2", "xmm3",
+                                              "xmm4", "xmm5", "xmm6", "xmm7" };
+        return Names[code];
+    }
+
+    static Code FromName(const char *name) {
+        for (size_t i = 0; i < Total; i++) {
+            if (strcmp(GetName(Code(i)), name) == 0)
+                return Code(i);
+        }
+        return Invalid;
+    }
+
+    static const Code Invalid = JSC::X86Registers::invalid_xmm;
+
+    static const uint32_t Total = 8;
+    static const uint32_t Allocatable = 7;
+
+    static const uint32_t AllMask = (1 << Total) - 1;
+
+    static const uint32_t VolatileMask = AllMask;
+    static const uint32_t NonVolatileMask = 0;
+
+    static const uint32_t WrapperMask = VolatileMask;
+
+    static const uint32_t NonAllocatableMask =
+        (1 << JSC::X86Registers::xmm7);
+
+    static const uint32_t AllocatableMask = AllMask & ~NonAllocatableMask;
+};
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_x86_Architecture_x86_h */