diff -r 000000000000 -r 6474c204b198 js/src/jit/arm/BaselineHelpers-arm.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/js/src/jit/arm/BaselineHelpers-arm.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,334 @@ +/* -*- 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_BaselineHelpers_arm_h +#define jit_arm_BaselineHelpers_arm_h + +#ifdef JS_ION +#include "jit/BaselineFrame.h" +#include "jit/BaselineIC.h" +#include "jit/BaselineRegisters.h" +#include "jit/IonMacroAssembler.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(CodeOffsetLabel *patchOffset, MacroAssembler &masm) +{ + // Move ICEntry offset into BaselineStubReg + CodeOffsetLabel offset = masm.movWithPatch(ImmWord(-1), BaselineStubReg); + *patchOffset = offset; + + // Load stub pointer into BaselineStubReg + masm.loadPtr(Address(BaselineStubReg, ICEntry::offsetOfFirstStub()), BaselineStubReg); + + // Load stubcode pointer from BaselineStubEntry. + // R2 won't be active when we call ICs, so we can use r0. + JS_ASSERT(R2 == ValueOperand(r1, r0)); + masm.loadPtr(Address(BaselineStubReg, 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 BaselineStubReg + // is properly initialized to point to the stub. + masm.loadPtr(Address(BaselineStubReg, (uint32_t) monitorStubOffset), BaselineStubReg); + + // Load stubcode pointer from BaselineStubEntry. + // R2 won't be active when we call ICs, so we can use r0. + JS_ASSERT(R2 == ValueOperand(r1, r0)); + masm.loadPtr(Address(BaselineStubReg, 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 +EmitTailCallVM(JitCode *target, MacroAssembler &masm, uint32_t argSize) +{ + // We assume during this that R0 and R1 have been pushed, and that R2 is + // unused. + JS_ASSERT(R2 == ValueOperand(r1, r0)); + + // Compute frame size. + masm.movePtr(BaselineFrameReg, r0); + masm.ma_add(Imm32(BaselineFrame::FramePointerOffset), r0); + masm.ma_sub(BaselineStackReg, r0); + + // Store frame size without VMFunction arguments for GC marking. + masm.ma_sub(r0, Imm32(argSize), r1); + masm.store32(r1, Address(BaselineFrameReg, BaselineFrame::reverseOffsetOfFrameSize())); + + // Push frame descriptor and perform the tail call. + // BaselineTailCallReg (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. + JS_ASSERT(BaselineTailCallReg == lr); + masm.makeFrameDescriptor(r0, JitFrame_BaselineJS); + masm.push(r0); + masm.push(lr); + masm.branch(target); +} + +inline void +EmitCreateStubFrameDescriptor(MacroAssembler &masm, Register reg) +{ + // 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.ma_add(Imm32(sizeof(void *) * 2), reg); + masm.ma_sub(BaselineStackReg, reg); + + masm.makeFrameDescriptor(reg, JitFrame_BaselineStub); +} + +inline void +EmitCallVM(JitCode *target, MacroAssembler &masm) +{ + EmitCreateStubFrameDescriptor(masm, r0); + masm.push(r0); + masm.call(target); +} + +// 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 +EmitEnterStubFrame(MacroAssembler &masm, Register scratch) +{ + JS_ASSERT(scratch != BaselineTailCallReg); + + // Compute frame size. + masm.mov(BaselineFrameReg, scratch); + masm.ma_add(Imm32(BaselineFrame::FramePointerOffset), scratch); + 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); + masm.push(scratch); + masm.push(BaselineTailCallReg); + + // Save old frame pointer, stack pointer and stub reg. + masm.push(BaselineStubReg); + masm.push(BaselineFrameReg); + masm.mov(BaselineStackReg, BaselineFrameReg); + + // We pushed 4 words, so the stack is still aligned to 8 bytes. + masm.checkStackAlignment(); +} + +inline void +EmitLeaveStubFrameHead(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) { + masm.pop(ScratchRegister); + masm.ma_lsr(Imm32(FRAMESIZE_SHIFT), ScratchRegister, ScratchRegister); + masm.ma_add(ScratchRegister, BaselineStackReg); + } else { + masm.mov(BaselineFrameReg, BaselineStackReg); + } +} + +inline void +EmitLeaveStubFrameCommonTail(MacroAssembler &masm) +{ + masm.pop(BaselineFrameReg); + masm.pop(BaselineStubReg); + + // Load the return address. + masm.pop(BaselineTailCallReg); + + // Discard the frame descriptor. + masm.pop(ScratchRegister); +} + +inline void +EmitLeaveStubFrame(MacroAssembler &masm, bool calledIntoIon = false) +{ + EmitLeaveStubFrameHead(masm, calledIntoIon); + EmitLeaveStubFrameCommonTail(masm); +} + +inline void +EmitStowICValues(MacroAssembler &masm, int values) +{ + JS_ASSERT(values >= 0 && values <= 2); + switch(values) { + case 1: + // Stow R0 + masm.pushValue(R0); + break; + case 2: + // Stow R0 and R1 + masm.pushValue(R0); + masm.pushValue(R1); + break; + } +} + +inline void +EmitUnstowICValues(MacroAssembler &masm, int values, bool discard = false) +{ + JS_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; + } +} + +inline void +EmitCallTypeUpdateIC(MacroAssembler &masm, JitCode *code, uint32_t objectOffset) +{ + JS_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 BaselineStubReg to stack, as well as the TailCallReg, + // since on ARM, the LR is live. + masm.push(BaselineStubReg); + masm.push(BaselineTailCallReg); + + // This is expected to be called from within an IC, when BaselineStubReg + // is properly initialized to point to the stub. + masm.loadPtr(Address(BaselineStubReg, ICUpdatedStub::offsetOfFirstUpdateStub()), + BaselineStubReg); + + // TODO: Change r0 uses below to use masm's configurable scratch register instead. + + // Load stubcode pointer from BaselineStubReg into BaselineTailCallReg. + masm.loadPtr(Address(BaselineStubReg, ICStub::offsetOfStubCode()), r0); + + // Call the stubcode. + masm.ma_blx(r0); + + // Restore the old stub reg and tailcall reg. + masm.pop(BaselineTailCallReg); + masm.pop(BaselineStubReg); + + // 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. + EmitEnterStubFrame(masm, R1.scratchReg()); + + masm.loadValue(Address(BaselineStackReg, STUB_FRAME_SIZE + objectOffset), R1); + + masm.pushValue(R0); + masm.pushValue(R1); + masm.push(BaselineStubReg); + + // Load previous frame pointer, push BaselineFrame *. + masm.loadPtr(Address(BaselineFrameReg, 0), R0.scratchReg()); + masm.pushBaselineFramePtr(R0.scratchReg(), R0.scratchReg()); + + EmitCallVM(code, masm); + EmitLeaveStubFrame(masm); + + // Success at end. + masm.bind(&success); +} + +template +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) +{ + JS_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 BaselineStubReg + masm.loadPtr(Address(BaselineStubReg, ICStub::offsetOfNext()), BaselineStubReg); + + // Load stubcode pointer from BaselineStubEntry into scratch register. + masm.loadPtr(Address(BaselineStubReg, ICStub::offsetOfStubCode()), r0); + + // Return address is already loaded, just jump to the next stubcode. + JS_ASSERT(BaselineTailCallReg == lr); + masm.branch(r0); +} + + +} // namespace jit +} // namespace js + +#endif // JS_ION + +#endif /* jit_arm_BaselineHelpers_arm_h */ +