diff -r 000000000000 -r 6474c204b198 js/src/jit/mips/Bailouts-mips.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit/mips/Bailouts-mips.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,77 @@
+/* -*- 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_mips_Bailouts_mips_h
+#define jit_mips_Bailouts_mips_h
+
+#include "jit/Bailouts.h"
+#include "jit/JitCompartment.h"
+
+namespace js {
+namespace jit {
+
+class BailoutStack
+{
+    uintptr_t frameClassId_;
+    // This is pushed in the bailout handler.  Both entry points into the
+    // handler inserts their own value int lr, which is then placed onto the
+    // stack along with frameClassId_ above.  This should be migrated to ip.
+  public:
+    union {
+        uintptr_t frameSize_;
+        uintptr_t tableOffset_;
+    };
+
+  protected:
+    mozilla::Array<double, FloatRegisters::Total> fpregs_;
+    mozilla::Array<uintptr_t, Registers::Total> regs_;
+
+    uintptr_t snapshotOffset_;
+    uintptr_t padding_;
+
+  public:
+    FrameSizeClass frameClass() const {
+        return FrameSizeClass::FromClass(frameClassId_);
+    }
+    uintptr_t tableOffset() const {
+        MOZ_ASSERT(frameClass() != FrameSizeClass::None());
+        return tableOffset_;
+    }
+    uint32_t frameSize() const {
+        if (frameClass() == FrameSizeClass::None())
+            return frameSize_;
+        return frameClass().frameSize();
+    }
+    MachineState machine() {
+        return MachineState::FromBailout(regs_, fpregs_);
+    }
+    SnapshotOffset snapshotOffset() const {
+        MOZ_ASSERT(frameClass() == FrameSizeClass::None());
+        return snapshotOffset_;
+    }
+    uint8_t *parentStackPointer() const {
+        if (frameClass() == FrameSizeClass::None())
+            return (uint8_t *)this + sizeof(BailoutStack);
+        return (uint8_t *)this + offsetof(BailoutStack, snapshotOffset_);
+    }
+    static size_t offsetOfFrameClass() {
+        return offsetof(BailoutStack, frameClassId_);
+    }
+    static size_t offsetOfFrameSize() {
+        return offsetof(BailoutStack, frameSize_);
+    }
+    static size_t offsetOfFpRegs() {
+        return offsetof(BailoutStack, fpregs_);
+    }
+    static size_t offsetOfRegs() {
+        return offsetof(BailoutStack, regs_);
+    }
+};
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_mips_Bailouts_mips_h */