tor-browser

The Tor Browser
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SharedICHelpers-x86-inl.h (2490B)

      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_x86_SharedICHelpers_x86_inl_h
      8 #define jit_x86_SharedICHelpers_x86_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  // We assume during this that R0 and R1 have been pushed.
     22  // Store frame size without VMFunction arguments for debug assertions.
     23  masm.movl(FramePointer, eax);
     24  masm.subl(StackPointer, eax);
     25  masm.subl(Imm32(argSize), eax);
     26  Address frameSizeAddr(FramePointer,
     27                        BaselineFrame::reverseOffsetOfDebugFrameSize());
     28  masm.store32(eax, frameSizeAddr);
     29 #endif
     30 
     31  // Push frame descriptor and perform the tail call.
     32  masm.push(FrameDescriptor(FrameType::BaselineJS));
     33  masm.push(ICTailCallReg);
     34  masm.jump(target);
     35 }
     36 
     37 inline void EmitBaselineCallVM(TrampolinePtr target, MacroAssembler& masm) {
     38  masm.push(FrameDescriptor(FrameType::BaselineStub));
     39  masm.call(target);
     40 }
     41 
     42 inline void EmitBaselineEnterStubFrame(MacroAssembler& masm, Register scratch) {
     43 #ifdef DEBUG
     44  // Compute frame size. Because the return address is still on the stack,
     45  // this is:
     46  //
     47  //   FramePointer
     48  //   - StackPointer
     49  //   - sizeof(return address)
     50 
     51  masm.movl(FramePointer, scratch);
     52  masm.subl(StackPointer, scratch);
     53  masm.subl(Imm32(sizeof(void*)), scratch);  // Return address.
     54 
     55  Address frameSizeAddr(FramePointer,
     56                        BaselineFrame::reverseOffsetOfDebugFrameSize());
     57  masm.store32(scratch, frameSizeAddr);
     58 #endif
     59 
     60  // Push the return address that's currently on top of the stack.
     61  masm.Push(Operand(StackPointer, 0));
     62 
     63  // Replace the original return address with the frame descriptor.
     64  masm.storePtr(ImmWord(MakeFrameDescriptor(FrameType::BaselineJS)),
     65                Address(StackPointer, sizeof(uintptr_t)));
     66 
     67  // Save old frame pointer, stack pointer and stub reg.
     68  masm.Push(FramePointer);
     69  masm.mov(StackPointer, FramePointer);
     70 
     71  masm.Push(ICStubReg);
     72 }
     73 
     74 }  // namespace jit
     75 }  // namespace js
     76 
     77 #endif /* jit_x86_SharedICHelpers_x86_inl_h */