tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

SharedICHelpers-arm-inl.h (2586B)

      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_arm_SharedICHelpers_arm_inl_h
      8 #define jit_arm_SharedICHelpers_arm_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, and that R2 is
     22  // unused.
     23  static_assert(R2 == ValueOperand(r1, r0));
     24 
     25  // Store frame size without VMFunction arguments for debug assertions.
     26  masm.movePtr(FramePointer, r0);
     27  masm.ma_sub(StackPointer, r0);
     28  masm.sub32(Imm32(argSize), r0);
     29  Address frameSizeAddr(FramePointer,
     30                        BaselineFrame::reverseOffsetOfDebugFrameSize());
     31  masm.store32(r0, frameSizeAddr);
     32 #endif
     33 
     34  // Push frame descriptor and perform the tail call.
     35  masm.push(FrameDescriptor(FrameType::BaselineJS));
     36 
     37  static_assert(ICTailCallReg == lr);
     38  // The return address will be pushed by the VM wrapper, for compatibility
     39  // with direct calls. Refer to the top of generateVMWrapper().
     40  // ICTailCallReg (lr) already contains the return address (as we keep
     41  // it there through the stub calls).
     42 
     43  masm.jump(target);
     44 }
     45 
     46 inline void EmitBaselineCallVM(TrampolinePtr target, MacroAssembler& masm) {
     47  masm.push(FrameDescriptor(FrameType::BaselineStub));
     48  masm.call(target);
     49 }
     50 
     51 inline void EmitBaselineEnterStubFrame(MacroAssembler& masm, Register scratch) {
     52  MOZ_ASSERT(scratch != ICTailCallReg);
     53 
     54 #ifdef DEBUG
     55  // Compute frame size.
     56  masm.mov(FramePointer, scratch);
     57  masm.ma_sub(StackPointer, scratch);
     58 
     59  Address frameSizeAddr(FramePointer,
     60                        BaselineFrame::reverseOffsetOfDebugFrameSize());
     61  masm.store32(scratch, frameSizeAddr);
     62 #endif
     63 
     64  // Push frame descriptor and return address.
     65  masm.Push(FrameDescriptor(FrameType::BaselineJS));
     66  masm.Push(ICTailCallReg);
     67 
     68  // Save old frame pointer, stack pointer and stub reg.
     69  masm.Push(FramePointer);
     70  masm.mov(StackPointer, FramePointer);
     71 
     72  masm.Push(ICStubReg);
     73 
     74  // We pushed 4 words, so the stack is still aligned to 8 bytes.
     75  masm.checkStackAlignment();
     76 }
     77 
     78 }  // namespace jit
     79 }  // namespace js
     80 
     81 #endif /* jit_arm_SharedICHelpers_arm_inl_h */