/* -*- 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_x86_SharedICHelpers_x86_h #define jit_x86_SharedICHelpers_x86_h #include "jit/BaselineFrame.h" #include "jit/BaselineIC.h" #include "jit/MacroAssembler.h" #include "jit/SharedICRegisters.h" namespace js { namespace jit { // Distance from stack top to the top Value inside an IC stub (this is the return address). static const size_t ICStackValueOffset = sizeof(void*); inline void EmitRestoreTailCallReg(MacroAssembler& masm) { masm.Pop(ICTailCallReg); } inline void EmitRepushTailCallReg(MacroAssembler& masm) { masm.Push(ICTailCallReg); } 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, (int32_t) ICEntry::offsetOfFirstStub()), ICStubReg); // Load stubcode pointer from BaselineStubEntry into ICTailCallReg // ICTailCallReg will always be unused in the contexts where ICs are called. masm.call(Address(ICStubReg, ICStub::offsetOfStubCode())); } 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, (int32_t) monitorStubOffset), ICStubReg); // Jump to the stubcode. masm.jmp(Operand(ICStubReg, (int32_t) ICStub::offsetOfStubCode())); } inline void EmitReturnFromIC(MacroAssembler& masm) { masm.ret(); } inline void EmitChangeICReturnAddress(MacroAssembler& masm, Register reg) { masm.storePtr(reg, Address(StackPointer, 0)); } inline void EmitBaselineTailCallVM(JitCode* target, MacroAssembler& masm, uint32_t argSize) { // We assume during this that R0 and R1 have been pushed. // Compute frame size. masm.movl(BaselineFrameReg, eax); masm.addl(Imm32(BaselineFrame::FramePointerOffset), eax); masm.subl(BaselineStackReg, eax); // Store frame size without VMFunction arguments for GC marking. masm.movl(eax, ebx); masm.subl(Imm32(argSize), ebx); masm.store32(ebx, Address(BaselineFrameReg, BaselineFrame::reverseOffsetOfFrameSize())); // Push frame descriptor and perform the tail call. masm.makeFrameDescriptor(eax, JitFrame_BaselineJS, ExitFrameLayout::Size()); masm.push(eax); masm.push(ICTailCallReg); masm.jmp(target); } inline void EmitIonTailCallVM(JitCode* target, MacroAssembler& masm, uint32_t stackSize) { // For tail calls, find the already pushed JitFrame_IonJS signifying the // end of the Ion frame. Retrieve the length of the frame and repush // JitFrame_IonJS with the extra stacksize, rendering the original // JitFrame_IonJS obsolete. masm.loadPtr(Address(esp, stackSize), eax); masm.shrl(Imm32(FRAMESIZE_SHIFT), eax); masm.addl(Imm32(stackSize + JitStubFrameLayout::Size() - sizeof(intptr_t)), eax); // Push frame descriptor and perform the tail call. masm.makeFrameDescriptor(eax, JitFrame_IonJS, ExitFrameLayout::Size()); masm.push(eax); masm.push(ICTailCallReg); masm.jmp(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.movl(BaselineFrameReg, reg); masm.addl(Imm32(sizeof(void*) * 2), reg); masm.subl(BaselineStackReg, reg); masm.makeFrameDescriptor(reg, JitFrame_BaselineStub, headerSize); } inline void EmitBaselineCallVM(JitCode* target, MacroAssembler& masm) { EmitBaselineCreateStubFrameDescriptor(masm, eax, ExitFrameLayout::Size()); masm.push(eax); masm.call(target); } inline void EmitIonCallVM(JitCode* target, size_t stackSlots, MacroAssembler& masm) { // Stubs often use the return address. Which is actually accounted by the // caller of the stub. Though in the stubcode we fake that is part of the // stub. In order to make it possible to pop it. As a result we have to // fix it here, by subtracting it. Else it would be counted twice. uint32_t framePushed = masm.framePushed() - sizeof(void*); uint32_t descriptor = MakeFrameDescriptor(framePushed, JitFrame_IonStub, ExitFrameLayout::Size()); masm.Push(Imm32(descriptor)); masm.call(target); // Remove rest of the frame left on the stack. We remove the return address // which is implicitly poped 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); EmitRestoreTailCallReg(masm); // Compute frame size. masm.movl(BaselineFrameReg, scratch); masm.addl(Imm32(BaselineFrame::FramePointerOffset), scratch); masm.subl(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); } inline void EmitIonEnterStubFrame(MacroAssembler& masm, Register scratch) { MOZ_ASSERT(scratch != ICTailCallReg); masm.loadPtr(Address(masm.getStackPointer(), 0), ICTailCallReg); masm.Push(ICStubReg); } inline void EmitBaselineLeaveStubFrame(MacroAssembler& masm, bool calledIntoIon = false) { // 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) { Register scratch = ICTailCallReg; masm.Pop(scratch); masm.shrl(Imm32(FRAMESIZE_SHIFT), scratch); masm.addl(scratch, BaselineStackReg); } else { masm.mov(BaselineFrameReg, BaselineStackReg); } masm.Pop(BaselineFrameReg); masm.Pop(ICStubReg); // Pop return address. masm.Pop(ICTailCallReg); // Overwrite frame descriptor with return address, so that the stack matches // the state before entering the stub frame. masm.storePtr(ICTailCallReg, Address(BaselineStackReg, 0)); } inline void EmitIonLeaveStubFrame(MacroAssembler& masm) { masm.Pop(ICStubReg); } inline void EmitStowICValues(MacroAssembler& masm, int values) { MOZ_ASSERT(values >= 0 && values <= 2); switch(values) { case 1: // Stow R0 masm.pop(ICTailCallReg); masm.Push(R0); masm.push(ICTailCallReg); break; case 2: // Stow R0 and R1 masm.pop(ICTailCallReg); masm.Push(R0); masm.Push(R1); masm.push(ICTailCallReg); break; } } inline void EmitUnstowICValues(MacroAssembler& masm, int values, bool discard = false) { MOZ_ASSERT(values >= 0 && values <= 2); switch(values) { case 1: // Unstow R0 masm.pop(ICTailCallReg); if (discard) masm.addPtr(Imm32(sizeof(Value)), BaselineStackReg); else masm.popValue(R0); masm.push(ICTailCallReg); break; case 2: // Unstow R0 and R1 masm.pop(ICTailCallReg); if (discard) { masm.addPtr(Imm32(sizeof(Value) * 2), BaselineStackReg); } else { masm.popValue(R1); masm.popValue(R0); } masm.push(ICTailCallReg); break; } masm.adjustFrame(-values * sizeof(Value)); } inline void EmitCallTypeUpdateIC(MacroAssembler& masm, JitCode* code, uint32_t objectOffset) { // 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 stack top, excluding the return address. // Save the current ICStubReg to stack masm.push(ICStubReg); // This is expected to be called from within an IC, when ICStubReg // is properly initialized to point to the stub. masm.loadPtr(Address(ICStubReg, (int32_t) ICUpdatedStub::offsetOfFirstUpdateStub()), ICStubReg); // Call the stubcode. masm.call(Address(ICStubReg, ICStub::offsetOfStubCode())); // Restore the old stub reg. 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) { masm.patchableCallPreBarrier(addr, type); } inline void EmitStubGuardFailure(MacroAssembler& masm) { // 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, (int32_t) ICStub::offsetOfNext()), ICStubReg); // Return address is already loaded, just jump to the next stubcode. masm.jmp(Operand(ICStubReg, (int32_t) ICStub::offsetOfStubCode())); } } // namespace jit } // namespace js #endif /* jit_x86_SharedICHelpers_x86_h */