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+/* -*- 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 */