/* -*- 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_arm_SharedICHelpers_arm_h #define jit_arm_SharedICHelpers_arm_h #include "jit/BaselineFrame.h" #include "jit/BaselineIC.h" #include "jit/MacroAssembler.h" #include "jit/SharedICRegisters.h" namespace js { namespace jit { // Distance from sp to the top Value inside an IC stub (no return address on the stack on ARM). static const size_t ICStackValueOffset = 0; inline void EmitRestoreTailCallReg(MacroAssembler& masm) { // No-op on ARM because link register is always holding the return address. } inline void EmitRepushTailCallReg(MacroAssembler& masm) { // No-op on ARM because link register is always holding the return address. } inline void EmitCallIC(CodeOffset* patchOffset, MacroAssembler& masm) { // Move ICEntry offset into ICStubReg CodeOffset offset = masm.movWithPatch(ImmWord(-1), ICStubReg); *patchOffset = offset; // Load stub pointer into ICStubReg masm.loadPtr(Address(ICStubReg, ICEntry::offsetOfFirstStub()), ICStubReg); // Load stubcode pointer from BaselineStubEntry. // R2 won't be active when we call ICs, so we can use r0. MOZ_ASSERT(R2 == ValueOperand(r1, r0)); masm.loadPtr(Address(ICStubReg, ICStub::offsetOfStubCode()), r0); // Call the stubcode via a direct branch-and-link. masm.ma_blx(r0); } inline void EmitEnterTypeMonitorIC(MacroAssembler& masm, size_t monitorStubOffset = ICMonitoredStub::offsetOfFirstMonitorStub()) { // This is expected to be called from within an IC, when ICStubReg is // properly initialized to point to the stub. masm.loadPtr(Address(ICStubReg, (uint32_t) monitorStubOffset), ICStubReg); // Load stubcode pointer from BaselineStubEntry. // R2 won't be active when we call ICs, so we can use r0. MOZ_ASSERT(R2 == ValueOperand(r1, r0)); masm.loadPtr(Address(ICStubReg, ICStub::offsetOfStubCode()), r0); // Jump to the stubcode. masm.branch(r0); } inline void EmitReturnFromIC(MacroAssembler& masm) { masm.ma_mov(lr, pc); } inline void EmitChangeICReturnAddress(MacroAssembler& masm, Register reg) { masm.ma_mov(reg, lr); } inline void EmitBaselineTailCallVM(JitCode* target, MacroAssembler& masm, uint32_t argSize) { // We assume during this that R0 and R1 have been pushed, and that R2 is // unused. MOZ_ASSERT(R2 == ValueOperand(r1, r0)); // Compute frame size. masm.movePtr(BaselineFrameReg, r0); masm.as_add(r0, r0, Imm8(BaselineFrame::FramePointerOffset)); masm.ma_sub(BaselineStackReg, r0); // Store frame size without VMFunction arguments for GC marking. { ScratchRegisterScope scratch(masm); masm.ma_sub(r0, Imm32(argSize), r1, scratch); } masm.store32(r1, Address(BaselineFrameReg, BaselineFrame::reverseOffsetOfFrameSize())); // Push frame descriptor and perform the tail call. // ICTailCallReg (lr) already contains the return address (as we keep // it there through the stub calls), but the VMWrapper code being called // expects the return address to also be pushed on the stack. MOZ_ASSERT(ICTailCallReg == lr); masm.makeFrameDescriptor(r0, JitFrame_BaselineJS, ExitFrameLayout::Size()); masm.push(r0); masm.push(lr); masm.branch(target); } inline void EmitIonTailCallVM(JitCode* target, MacroAssembler& masm, uint32_t stackSize) { // We assume during this that R0 and R1 have been pushed, and that R2 is // unused. MOZ_ASSERT(R2 == ValueOperand(r1, r0)); masm.loadPtr(Address(sp, stackSize), r0); masm.rshiftPtr(Imm32(FRAMESIZE_SHIFT), r0); masm.add32(Imm32(stackSize + JitStubFrameLayout::Size() - sizeof(intptr_t)), r0); // Push frame descriptor and perform the tail call. // ICTailCallReg (lr) already contains the return address (as we keep // it there through the stub calls), but the VMWrapper code being called // expects the return address to also be pushed on the stack. MOZ_ASSERT(ICTailCallReg == lr); masm.makeFrameDescriptor(r0, JitFrame_IonJS, ExitFrameLayout::Size()); masm.push(r0); masm.push(lr); masm.branch(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.mov(BaselineFrameReg, reg); masm.as_add(reg, reg, Imm8(sizeof(void*) * 2)); masm.ma_sub(BaselineStackReg, reg); masm.makeFrameDescriptor(reg, JitFrame_BaselineStub, headerSize); } inline void EmitBaselineCallVM(JitCode* target, MacroAssembler& masm) { EmitBaselineCreateStubFrameDescriptor(masm, r0, ExitFrameLayout::Size()); masm.push(r0); masm.call(target); } inline void EmitIonCallVM(JitCode* target, size_t stackSlots, MacroAssembler& masm) { uint32_t descriptor = MakeFrameDescriptor(masm.framePushed(), JitFrame_IonStub, ExitFrameLayout::Size()); masm.Push(Imm32(descriptor)); masm.callJit(target); // Remove rest of the frame left on the stack. We remove the return address // which is implicitly popped when returning. size_t framePop = sizeof(ExitFrameLayout) - sizeof(void*); // Pop arguments from framePushed. masm.implicitPop(stackSlots * sizeof(void*) + framePop); } // Size of vales pushed by EmitEnterStubFrame. 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 scratch) { MOZ_ASSERT(scratch != ICTailCallReg); // Compute frame size. masm.mov(BaselineFrameReg, scratch); masm.as_add(scratch, scratch, Imm8(BaselineFrame::FramePointerOffset)); masm.ma_sub(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 frame descriptor and return address. masm.makeFrameDescriptor(scratch, JitFrame_BaselineJS, BaselineStubFrameLayout::Size()); masm.Push(scratch); masm.Push(ICTailCallReg); // Save old frame pointer, stack pointer and stub reg. masm.Push(ICStubReg); masm.Push(BaselineFrameReg); masm.mov(BaselineStackReg, BaselineFrameReg); // We pushed 4 words, so the stack is still aligned to 8 bytes. masm.checkStackAlignment(); } inline void EmitIonEnterStubFrame(MacroAssembler& masm, Register scratch) { MOZ_ASSERT(ICTailCallReg == lr); // In arm the link register contains the return address, // but in jit frames we expect it to be on the stack. As a result // push the link register (which is actually part of the previous frame. // Therefore using push instead of Push). masm.push(ICTailCallReg); masm.Push(ICStubReg); } inline void EmitBaselineLeaveStubFrame(MacroAssembler& masm, bool calledIntoIon = false) { ScratchRegisterScope scratch(masm); // Ion frames do not save and restore the frame pointer. If we called into // Ion, we have to restore the stack pointer from the frame descriptor. If // we performed a VM call, the descriptor has been popped already so in that // case we use the frame pointer. if (calledIntoIon) { masm.Pop(scratch); masm.rshiftPtr(Imm32(FRAMESIZE_SHIFT), scratch); masm.add32(scratch, BaselineStackReg); } else { masm.mov(BaselineFrameReg, BaselineStackReg); } masm.Pop(BaselineFrameReg); masm.Pop(ICStubReg); // Load the return address. masm.Pop(ICTailCallReg); // Discard the frame descriptor. masm.Pop(scratch); } inline void EmitIonLeaveStubFrame(MacroAssembler& masm) { masm.Pop(ICStubReg); masm.pop(ICTailCallReg); // See EmitIonEnterStubFrame for explanation on pop/Pop. } inline void EmitStowICValues(MacroAssembler& masm, int values) { MOZ_ASSERT(values >= 0 && values <= 2); switch(values) { case 1: // Stow R0. masm.Push(R0); break; case 2: // Stow R0 and R1. masm.Push(R0); masm.Push(R1); break; } } inline void EmitUnstowICValues(MacroAssembler& masm, int values, bool discard = false) { MOZ_ASSERT(values >= 0 && values <= 2); switch(values) { case 1: // Unstow R0. if (discard) masm.addPtr(Imm32(sizeof(Value)), BaselineStackReg); else masm.popValue(R0); break; case 2: // Unstow R0 and R1. if (discard) { masm.addPtr(Imm32(sizeof(Value) * 2), BaselineStackReg); } else { masm.popValue(R1); masm.popValue(R0); } break; } masm.adjustFrame(-values * sizeof(Value)); } inline void EmitCallTypeUpdateIC(MacroAssembler& masm, JitCode* code, uint32_t objectOffset) { MOZ_ASSERT(R2 == ValueOperand(r1, r0)); // R0 contains the value that needs to be typechecked. The object we're // updating is a boxed Value on the stack, at offset objectOffset from esp, // excluding the return address. // Save the current ICStubReg to stack, as well as the TailCallReg, // since on ARM, the LR is live. masm.push(ICStubReg); masm.push(ICTailCallReg); // This is expected to be called from within an IC, when ICStubReg is // properly initialized to point to the stub. masm.loadPtr(Address(ICStubReg, ICUpdatedStub::offsetOfFirstUpdateStub()), ICStubReg); // TODO: Change r0 uses below to use masm's configurable scratch register instead. // Load stubcode pointer from ICStubReg into ICTailCallReg. masm.loadPtr(Address(ICStubReg, ICStub::offsetOfStubCode()), r0); // Call the stubcode. masm.ma_blx(r0); // Restore the old stub reg and tailcall reg. masm.pop(ICTailCallReg); masm.pop(ICStubReg); // The update IC will store 0 or 1 in R1.scratchReg() reflecting if the // value in R0 type-checked properly or not. Label success; masm.cmp32(R1.scratchReg(), Imm32(1)); masm.j(Assembler::Equal, &success); // If the IC failed, then call the update fallback function. EmitBaselineEnterStubFrame(masm, R1.scratchReg()); masm.loadValue(Address(BaselineStackReg, STUB_FRAME_SIZE + objectOffset), R1); masm.Push(R0); masm.Push(R1); masm.Push(ICStubReg); // Load previous frame pointer, push BaselineFrame*. masm.loadPtr(Address(BaselineFrameReg, 0), R0.scratchReg()); masm.pushBaselineFramePtr(R0.scratchReg(), R0.scratchReg()); EmitBaselineCallVM(code, masm); EmitBaselineLeaveStubFrame(masm); // Success at end. masm.bind(&success); } template <typename AddrType> inline void EmitPreBarrier(MacroAssembler& masm, const AddrType& addr, MIRType type) { // On ARM, lr is clobbered by patchableCallPreBarrier. Save it first. masm.push(lr); masm.patchableCallPreBarrier(addr, type); masm.pop(lr); } inline void EmitStubGuardFailure(MacroAssembler& masm) { MOZ_ASSERT(R2 == ValueOperand(r1, r0)); // NOTE: This routine assumes that the stub guard code left the stack in the // same state it was in when it was entered. // BaselineStubEntry points to the current stub. // Load next stub into ICStubReg. masm.loadPtr(Address(ICStubReg, ICStub::offsetOfNext()), ICStubReg); // Load stubcode pointer from BaselineStubEntry into scratch register. masm.loadPtr(Address(ICStubReg, ICStub::offsetOfStubCode()), r0); // Return address is already loaded, just jump to the next stubcode. MOZ_ASSERT(ICTailCallReg == lr); masm.branch(r0); } } // namespace jit } // namespace js #endif /* jit_arm_SharedICHelpers_arm_h */