/* -*- 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_x64_SharedICHelpers_x64_inl_h

#define jit_x64_SharedICHelpers_x64_inl_h

#include "jit/SharedICHelpers.h"

#include "jit/MacroAssembler-inl.h"

namespace js {

namespace jit {

inline void

EmitBaselineTailCallVM(TrampolinePtr target, MacroAssembler& masm, uint32_t argSize)

{

    ScratchRegisterScope scratch(masm);

    // We an assume during this that R0 and R1 have been pushed.

    masm.movq(BaselineFrameReg, scratch);

    masm.addq(Imm32(BaselineFrame::FramePointerOffset), scratch);

    masm.subq(BaselineStackReg, scratch);

    // Store frame size without VMFunction arguments for GC marking.

    masm.movq(scratch, rdx);

    masm.subq(Imm32(argSize), rdx);

    masm.store32(rdx, Address(BaselineFrameReg, BaselineFrame::reverseOffsetOfFrameSize()));

    // Push frame descriptor and perform the tail call.

    masm.makeFrameDescriptor(scratch, FrameType::BaselineJS, ExitFrameLayout::Size());

    masm.push(scratch);

    masm.push(ICTailCallReg);

    masm.jump(target);

}

inline void

EmitBaselineCreateStubFrameDescriptor(MacroAssembler& masm, Register reg, uint32_t headerSize)

{

    // Compute stub frame size. We have to add two pointers: the stub reg and previous

    // frame pointer pushed by EmitEnterStubFrame.

    masm.movq(BaselineFrameReg, reg);

    masm.addq(Imm32(sizeof(void*) * 2), reg);

    masm.subq(BaselineStackReg, reg);

    masm.makeFrameDescriptor(reg, FrameType::BaselineStub, headerSize);

}

inline void

EmitBaselineCallVM(TrampolinePtr target, MacroAssembler& masm)

{

    ScratchRegisterScope scratch(masm);

    EmitBaselineCreateStubFrameDescriptor(masm, scratch, ExitFrameLayout::Size());

    masm.push(scratch);

    masm.call(target);

}

// Size of values pushed by EmitBaselineEnterStubFrame.

static const uint32_t STUB_FRAME_SIZE = 4 * sizeof(void*);

static const uint32_t STUB_FRAME_SAVED_STUB_OFFSET = sizeof(void*);

inline void

EmitBaselineEnterStubFrame(MacroAssembler& masm, Register)

{

    ScratchRegisterScope scratch(masm);

    // Compute frame size. Because the return address is still on the stack,

    // this is:

    //

    //   BaselineFrameReg

    //   + BaselineFrame::FramePointerOffset

    //   - BaselineStackReg

    //   - sizeof(return address)

    //

    // The two constants cancel each other out, so we can just calculate

    // BaselineFrameReg - BaselineStackReg.

    static_assert(BaselineFrame::FramePointerOffset == sizeof(void*),

                  "FramePointerOffset must be the same as the return address size");

    masm.movq(BaselineFrameReg, scratch);

    masm.subq(BaselineStackReg, scratch);

    masm.store32(scratch, Address(BaselineFrameReg, BaselineFrame::reverseOffsetOfFrameSize()));

    // Note: when making changes here,  don't forget to update STUB_FRAME_SIZE

    // if needed.

    // Push the return address that's currently on top of the stack.

    masm.Push(Operand(BaselineStackReg, 0));

    // Replace the original return address with the frame descriptor.

    masm.makeFrameDescriptor(scratch, FrameType::BaselineJS, BaselineStubFrameLayout::Size());

    masm.storePtr(scratch, Address(BaselineStackReg, sizeof(uintptr_t)));

    // Save old frame pointer, stack pointer and stub reg.

    masm.Push(ICStubReg);

    masm.Push(BaselineFrameReg);

    masm.mov(BaselineStackReg, BaselineFrameReg);

}

} // namespace jit

} // namespace js

#endif /* jit_x64_SharedICHelpers_x64_inl_h */