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SharedICHelpers-arm.h (2640B)

      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_h
      8 #define jit_arm_SharedICHelpers_arm_h
      9 
     10 #include "jit/BaselineIC.h"
     11 #include "jit/JitFrames.h"
     12 #include "jit/MacroAssembler.h"
     13 #include "jit/SharedICRegisters.h"
     14 
     15 namespace js {
     16 namespace jit {
     17 
     18 // Distance from sp to the top Value inside an IC stub (no return address on the
     19 // stack on ARM).
     20 static const size_t ICStackValueOffset = 0;
     21 
     22 inline void EmitRestoreTailCallReg(MacroAssembler& masm) {
     23  // No-op on ARM because link register is always holding the return address.
     24 }
     25 
     26 inline void EmitRepushTailCallReg(MacroAssembler& masm) {
     27  // No-op on ARM because link register is always holding the return address.
     28 }
     29 
     30 inline void EmitCallIC(MacroAssembler& masm, CodeOffset* callOffset) {
     31  // The stub pointer must already be in ICStubReg.
     32  // Load stubcode pointer from the ICStub.
     33  // R2 won't be active when we call ICs, so we can use r0.
     34  static_assert(R2 == ValueOperand(r1, r0));
     35  masm.loadPtr(Address(ICStubReg, ICStub::offsetOfStubCode()), r0);
     36 
     37  // Call the stubcode via a direct branch-and-link.
     38  masm.ma_blx(r0);
     39  *callOffset = CodeOffset(masm.currentOffset());
     40 }
     41 
     42 inline void EmitReturnFromIC(MacroAssembler& masm) { masm.ma_mov(lr, pc); }
     43 
     44 inline void EmitBaselineLeaveStubFrame(MacroAssembler& masm) {
     45  Address stubAddr(FramePointer, BaselineStubFrameLayout::ICStubOffsetFromFP);
     46  masm.loadPtr(stubAddr, ICStubReg);
     47 
     48  masm.mov(FramePointer, StackPointer);
     49  masm.Pop(FramePointer);
     50 
     51  // Load the return address.
     52  masm.Pop(ICTailCallReg);
     53 
     54  // Discard the frame descriptor.
     55  ScratchRegisterScope scratch(masm);
     56  masm.Pop(scratch);
     57 }
     58 
     59 template <typename AddrType>
     60 inline void EmitPreBarrier(MacroAssembler& masm, const AddrType& addr,
     61                           MIRType type) {
     62  // On ARM, lr is clobbered by guardedCallPreBarrier. Save it first.
     63  masm.push(lr);
     64  masm.guardedCallPreBarrier(addr, type);
     65  masm.pop(lr);
     66 }
     67 
     68 inline void EmitStubGuardFailure(MacroAssembler& masm) {
     69  // Load next stub into ICStubReg.
     70  masm.loadPtr(Address(ICStubReg, ICCacheIRStub::offsetOfNext()), ICStubReg);
     71 
     72  // Return address is already loaded, just jump to the next stubcode.
     73  static_assert(ICTailCallReg == lr);
     74  masm.jump(Address(ICStubReg, ICStub::offsetOfStubCode()));
     75 }
     76 
     77 }  // namespace jit
     78 }  // namespace js
     79 
     80 #endif /* jit_arm_SharedICHelpers_arm_h */