The Tor Browser: js/src/jit/mips/BaselineHelpers-mips.h@6474c204b198 (annotated)

js/src/jit/mips/BaselineHelpers-mips.h@6474c204b198 (annotated)

js/src/jit/mips/BaselineHelpers-mips.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- 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_mips_BaselineHelpers_mips_h
 #define jit_mips_BaselineHelpers_mips_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 MIPS).
 static const size_t ICStackValueOffset = 0;
 inline void
 EmitRestoreTailCallReg(MacroAssembler &masm)
 {
     // No-op on MIPS because ra register is always holding the return address.
 }
 inline void
 EmitRepushTailCallReg(MacroAssembler &masm)
 {
     // No-op on MIPS because ra 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 it as scratch.
     masm.loadPtr(Address(BaselineStubReg, ICStub::offsetOfStubCode()), R2.scratchReg());
     // Call the stubcode via a direct jump-and-link
     masm.call(R2.scratchReg());
 }
 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 it.
     masm.loadPtr(Address(BaselineStubReg, ICStub::offsetOfStubCode()), R2.scratchReg());
     // Jump to the stubcode.
     masm.branch(R2.scratchReg());
 }
 inline void
 EmitReturnFromIC(MacroAssembler &masm)
 {
     masm.branch(ra);
 }
 inline void
 EmitChangeICReturnAddress(MacroAssembler &masm, Register reg)
 {
     masm.movePtr(reg, ra);
 }
 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.
     MOZ_ASSERT(R2 == ValueOperand(t7, t6));
     // Compute frame size.
     masm.movePtr(BaselineFrameReg, t6);
     masm.addPtr(Imm32(BaselineFrame::FramePointerOffset), t6);
     masm.subPtr(BaselineStackReg, t6);
     // Store frame size without VMFunction arguments for GC marking.
     masm.ma_subu(t7, t6, Imm32(argSize));
     masm.storePtr(t7, Address(BaselineFrameReg, BaselineFrame::reverseOffsetOfFrameSize()));
     // Push frame descriptor and perform the tail call.
     // BaselineTailCallReg (ra) 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(BaselineTailCallReg == ra);
     masm.makeFrameDescriptor(t6, JitFrame_BaselineJS);
     masm.subPtr(Imm32(sizeof(IonCommonFrameLayout)), StackPointer);
     masm.storePtr(t6, Address(StackPointer, IonCommonFrameLayout::offsetOfDescriptor()));
     masm.storePtr(ra, Address(StackPointer, IonCommonFrameLayout::offsetOfReturnAddress()));
     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.movePtr(BaselineFrameReg, reg);
     masm.addPtr(Imm32(sizeof(intptr_t) * 2), reg);
     masm.subPtr(BaselineStackReg, reg);
     masm.makeFrameDescriptor(reg, JitFrame_BaselineStub);
 }
 inline void
 EmitCallVM(JitCode *target, MacroAssembler &masm)
 {
     EmitCreateStubFrameDescriptor(masm, t6);
     masm.push(t6);
     masm.call(target);
 }
 struct BaselineStubFrame {
     uintptr_t savedFrame;
     uintptr_t savedStub;
     uintptr_t returnAddress;
     uintptr_t descriptor;
 };
 static const uint32_t STUB_FRAME_SIZE = sizeof(BaselineStubFrame);
 static const uint32_t STUB_FRAME_SAVED_STUB_OFFSET = offsetof(BaselineStubFrame, savedStub);
 inline void
 EmitEnterStubFrame(MacroAssembler &masm, Register scratch)
 {
     MOZ_ASSERT(scratch != BaselineTailCallReg);
     // Compute frame size.
     masm.movePtr(BaselineFrameReg, scratch);
     masm.addPtr(Imm32(BaselineFrame::FramePointerOffset), scratch);
     masm.subPtr(BaselineStackReg, scratch);
     masm.storePtr(scratch, Address(BaselineFrameReg, BaselineFrame::reverseOffsetOfFrameSize()));
     // Note: when making changes here, don't forget to update
     // BaselineStubFrame if needed.
     // Push frame descriptor and return address.
     masm.makeFrameDescriptor(scratch, JitFrame_BaselineJS);
     masm.subPtr(Imm32(STUB_FRAME_SIZE), StackPointer);
     masm.storePtr(scratch, Address(StackPointer, offsetof(BaselineStubFrame, descriptor)));
     masm.storePtr(BaselineTailCallReg, Address(StackPointer,
                                                offsetof(BaselineStubFrame, returnAddress)));
     // Save old frame pointer, stack pointer and stub reg.
     masm.storePtr(BaselineStubReg, Address(StackPointer,
                                            offsetof(BaselineStubFrame, savedStub)));
     masm.storePtr(BaselineFrameReg, Address(StackPointer,
                                             offsetof(BaselineStubFrame, savedFrame)));
     masm.movePtr(BaselineStackReg, BaselineFrameReg);
     // We pushed 4 words, so the stack is still aligned to 8 bytes.
     masm.checkStackAlignment();
 }
 inline void
 EmitLeaveStubFrame(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.rshiftPtr(Imm32(FRAMESIZE_SHIFT), ScratchRegister);
         masm.addPtr(ScratchRegister, BaselineStackReg);
     } else {
         masm.movePtr(BaselineFrameReg, BaselineStackReg);
     }
     masm.loadPtr(Address(StackPointer, offsetof(BaselineStubFrame, savedFrame)),
                  BaselineFrameReg);
     masm.loadPtr(Address(StackPointer, offsetof(BaselineStubFrame, savedStub)),
                  BaselineStubReg);
     // Load the return address.
     masm.loadPtr(Address(StackPointer, offsetof(BaselineStubFrame, returnAddress)),
                  BaselineTailCallReg);
     // Discard the frame descriptor.
     masm.loadPtr(Address(StackPointer, offsetof(BaselineStubFrame, descriptor)), ScratchRegister);
     masm.addPtr(Imm32(STUB_FRAME_SIZE), StackPointer);
 }
 inline void
 EmitStowICValues(MacroAssembler &masm, int values)
 {
     MOZ_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)
 {
     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;
     }
 }
 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 $sp, excluding the return address.
     // Save the current BaselineStubReg to stack, as well as the TailCallReg,
     // since on mips, the $ra is live.
     masm.subPtr(Imm32(2 * sizeof(intptr_t)), StackPointer);
     masm.storePtr(BaselineStubReg, Address(StackPointer, sizeof(intptr_t)));
     masm.storePtr(BaselineTailCallReg, Address(StackPointer, 0));
     // 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);
     // Load stubcode pointer from BaselineStubReg into BaselineTailCallReg.
     masm.loadPtr(Address(BaselineStubReg, ICStub::offsetOfStubCode()), R2.scratchReg());
     // Call the stubcode.
     masm.call(R2.scratchReg());
     // Restore the old stub reg and tailcall reg.
     masm.loadPtr(Address(StackPointer, 0), BaselineTailCallReg);
     masm.loadPtr(Address(StackPointer, sizeof(intptr_t)), BaselineStubReg);
     masm.addPtr(Imm32(2 * sizeof(intptr_t)), StackPointer);
     // 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.ma_b(R1.scratchReg(), Imm32(1), &success, Assembler::Equal, ShortJump);
     // 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 <typename AddrType>
 inline void
 EmitPreBarrier(MacroAssembler &masm, const AddrType &addr, MIRType type)
 {
     // On MIPS, $ra is clobbered by patchableCallPreBarrier. Save it first.
     masm.push(ra);
     masm.patchableCallPreBarrier(addr, type);
     masm.pop(ra);
 }
 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 BaselineStubReg
     masm.loadPtr(Address(BaselineStubReg, ICStub::offsetOfNext()), BaselineStubReg);
     // Load stubcode pointer from BaselineStubEntry into scratch register.
     masm.loadPtr(Address(BaselineStubReg, ICStub::offsetOfStubCode()), R2.scratchReg());
     // Return address is already loaded, just jump to the next stubcode.
     MOZ_ASSERT(BaselineTailCallReg == ra);
     masm.branch(R2.scratchReg());
 }
 } // namespace jit
 } // namespace js
 #endif // JS_ION
 #endif /* jit_mips_BaselineHelpers_mips_h */

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js/src/jit/mips/BaselineHelpers-mips.h@6474c204b198 (annotated)

js/src/jit/mips/BaselineHelpers-mips.h