1 files changed, 353 insertions, 0 deletions
diff --git a/js/src/jit/x86/SharedICHelpers-x86.h b/js/src/jit/x86/SharedICHelpers-x86.h
new file mode 100644
index 000000000..e7f75cc95
--- /dev/null
+++ b/js/src/jit/x86/SharedICHelpers-x86.h
@@ -0,0 +1,353 @@
+/* -*- 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 */