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The Tor Browser
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SharedICHelpers-x64-inl.h (2579B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
      2 * vim: set ts=8 sts=2 et sw=2 tw=80:
      3 * This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #ifndef jit_x64_SharedICHelpers_x64_inl_h
      8 #define jit_x64_SharedICHelpers_x64_inl_h
      9 
     10 #include "jit/BaselineFrame.h"
     11 #include "jit/SharedICHelpers.h"
     12 
     13 #include "jit/MacroAssembler-inl.h"
     14 
     15 namespace js {
     16 namespace jit {
     17 
     18 inline void EmitBaselineTailCallVM(TrampolinePtr target, MacroAssembler& masm,
     19                                   uint32_t argSize) {
     20 #ifdef DEBUG
     21  ScratchRegisterScope scratch(masm);
     22 
     23  // We can assume during this that R0 and R1 have been pushed.
     24  // Store frame size without VMFunction arguments for debug assertions.
     25  masm.movq(FramePointer, scratch);
     26  masm.subq(StackPointer, scratch);
     27  masm.subq(Imm32(argSize), scratch);
     28  Address frameSizeAddr(FramePointer,
     29                        BaselineFrame::reverseOffsetOfDebugFrameSize());
     30  masm.store32(scratch, frameSizeAddr);
     31 #endif
     32 
     33  // Push frame descriptor and perform the tail call.
     34  masm.push(FrameDescriptor(FrameType::BaselineJS));
     35  masm.push(ICTailCallReg);
     36  masm.jump(target);
     37 }
     38 
     39 inline void EmitBaselineCallVM(TrampolinePtr target, MacroAssembler& masm) {
     40  masm.push(FrameDescriptor(FrameType::BaselineStub));
     41  masm.call(target);
     42 }
     43 
     44 inline void EmitBaselineEnterStubFrame(MacroAssembler& masm, Register) {
     45 #ifdef DEBUG
     46  // Compute frame size. Because the return address is still on the stack,
     47  // this is:
     48  //
     49  //   FramePointer
     50  //   - StackPointer
     51  //   - sizeof(return address)
     52 
     53  ScratchRegisterScope scratch(masm);
     54  masm.movq(FramePointer, scratch);
     55  masm.subq(StackPointer, scratch);
     56  masm.subq(Imm32(sizeof(void*)), scratch);  // Return address.
     57 
     58  Address frameSizeAddr(FramePointer,
     59                        BaselineFrame::reverseOffsetOfDebugFrameSize());
     60  masm.store32(scratch, frameSizeAddr);
     61 #endif
     62 
     63  // Push the return address that's currently on top of the stack.
     64  masm.Push(Operand(StackPointer, 0));
     65 
     66  // Replace the original return address with the frame descriptor.
     67  masm.storePtr(ImmWord(MakeFrameDescriptor(FrameType::BaselineJS)),
     68                Address(StackPointer, sizeof(uintptr_t)));
     69 
     70  // Save old frame pointer, stack pointer and stub reg.
     71  masm.Push(FramePointer);
     72  masm.mov(StackPointer, FramePointer);
     73 
     74  masm.Push(ICStubReg);
     75 }
     76 
     77 }  // namespace jit
     78 }  // namespace js
     79 
     80 #endif /* jit_x64_SharedICHelpers_x64_inl_h */