The Tor Browser: js/src/jit/mips/Trampoline-mips.cpp@129ffea94266 (annotated)

js/src/jit/mips/Trampoline-mips.cpp@129ffea94266 (annotated)

js/src/jit/mips/Trampoline-mips.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* -*- 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/. */
 #include "jscompartment.h"
 #include "jit/Bailouts.h"
 #include "jit/IonFrames.h"
 #include "jit/IonLinker.h"
 #include "jit/IonSpewer.h"
 #include "jit/JitCompartment.h"
 #include "jit/mips/Bailouts-mips.h"
 #include "jit/mips/BaselineHelpers-mips.h"
 #ifdef JS_ION_PERF
 # include "jit/PerfSpewer.h"
 #endif
 #include "jit/VMFunctions.h"
 #include "jit/ExecutionMode-inl.h"
 using namespace js;
 using namespace js::jit;
 static_assert(sizeof(uintptr_t) == sizeof(uint32_t), "Not 64-bit clean.");
 struct EnterJITRegs
 {
     double f30;
     double f28;
     double f26;
     double f24;
     double f22;
     double f20;
     // empty slot for alignment
     uintptr_t align;
     // non-volatile registers.
     uintptr_t ra;
     uintptr_t s7;
     uintptr_t s6;
     uintptr_t s5;
     uintptr_t s4;
     uintptr_t s3;
     uintptr_t s2;
     uintptr_t s1;
     uintptr_t s0;
 };
 struct EnterJITArgs
 {
     // First 4 argumet placeholders
     void *jitcode; // <- sp points here when function is entered.
     int maxArgc;
     Value *maxArgv;
     InterpreterFrame *fp;
     // Arguments on stack
     CalleeToken calleeToken;
     JSObject *scopeChain;
     size_t numStackValues;
     Value *vp;
 };
 static void
 GenerateReturn(MacroAssembler &masm, int returnCode)
 {
     MOZ_ASSERT(masm.framePushed() == sizeof(EnterJITRegs));
     // Restore non-volatile registers
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, s0)), s0);
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, s1)), s1);
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, s2)), s2);
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, s3)), s3);
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, s4)), s4);
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, s5)), s5);
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, s6)), s6);
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, s7)), s7);
     masm.loadPtr(Address(StackPointer, offsetof(EnterJITRegs, ra)), ra);
     // Restore non-volatile floating point registers
     masm.loadDouble(Address(StackPointer, offsetof(EnterJITRegs, f20)), f20);
     masm.loadDouble(Address(StackPointer, offsetof(EnterJITRegs, f22)), f22);
     masm.loadDouble(Address(StackPointer, offsetof(EnterJITRegs, f24)), f24);
     masm.loadDouble(Address(StackPointer, offsetof(EnterJITRegs, f26)), f26);
     masm.loadDouble(Address(StackPointer, offsetof(EnterJITRegs, f28)), f28);
     masm.loadDouble(Address(StackPointer, offsetof(EnterJITRegs, f30)), f30);
     masm.freeStack(sizeof(EnterJITRegs));
     masm.branch(ra);
 }
 static void
 GeneratePrologue(MacroAssembler &masm)
 {
     // Save non-volatile registers. These must be saved by the trampoline,
     // rather than the JIT'd code, because they are scanned by the conservative
     // scanner.
     masm.reserveStack(sizeof(EnterJITRegs));
     masm.storePtr(s0, Address(StackPointer, offsetof(EnterJITRegs, s0)));
     masm.storePtr(s1, Address(StackPointer, offsetof(EnterJITRegs, s1)));
     masm.storePtr(s2, Address(StackPointer, offsetof(EnterJITRegs, s2)));
     masm.storePtr(s3, Address(StackPointer, offsetof(EnterJITRegs, s3)));
     masm.storePtr(s4, Address(StackPointer, offsetof(EnterJITRegs, s4)));
     masm.storePtr(s5, Address(StackPointer, offsetof(EnterJITRegs, s5)));
     masm.storePtr(s6, Address(StackPointer, offsetof(EnterJITRegs, s6)));
     masm.storePtr(s7, Address(StackPointer, offsetof(EnterJITRegs, s7)));
     masm.storePtr(ra, Address(StackPointer, offsetof(EnterJITRegs, ra)));
     masm.as_sd(f20, StackPointer, offsetof(EnterJITRegs, f20));
     masm.as_sd(f22, StackPointer, offsetof(EnterJITRegs, f22));
     masm.as_sd(f24, StackPointer, offsetof(EnterJITRegs, f24));
     masm.as_sd(f26, StackPointer, offsetof(EnterJITRegs, f26));
     masm.as_sd(f28, StackPointer, offsetof(EnterJITRegs, f28));
     masm.as_sd(f30, StackPointer, offsetof(EnterJITRegs, f30));
 }
 /*
  * This method generates a trampoline for a c++ function with the following
  * signature:
  *   void enter(void *code, int argc, Value *argv, InterpreterFrame *fp,
  *              CalleeToken calleeToken, JSObject *scopeChain, Value *vp)
  *   ...using standard EABI calling convention
  */
 JitCode *
 JitRuntime::generateEnterJIT(JSContext *cx, EnterJitType type)
 {
     const Register reg_code = a0;
     const Register reg_argc = a1;
     const Register reg_argv = a2;
     const Register reg_frame = a3;
     MOZ_ASSERT(OsrFrameReg == reg_frame);
     MacroAssembler masm(cx);
     GeneratePrologue(masm);
     const Address slotToken(sp, sizeof(EnterJITRegs) + offsetof(EnterJITArgs, calleeToken));
     const Address slotVp(sp, sizeof(EnterJITRegs) + offsetof(EnterJITArgs, vp));
     // Save stack pointer into s4
     masm.movePtr(StackPointer, s4);
     // Load calleeToken into s2.
     masm.loadPtr(slotToken, s2);
     // Save stack pointer as baseline frame.
     if (type == EnterJitBaseline)
         masm.movePtr(StackPointer, BaselineFrameReg);
     // Load the number of actual arguments into s3.
     masm.loadPtr(slotVp, s3);
     masm.unboxInt32(Address(s3, 0), s3);
     /***************************************************************
     Loop over argv vector, push arguments onto stack in reverse order
     ***************************************************************/
     masm.as_sll(s0, reg_argc, 3); // s0 = argc * 8
     masm.addPtr(reg_argv, s0); // s0 = argv + argc * 8
     // Loop over arguments, copying them from an unknown buffer onto the Ion
     // stack so they can be accessed from JIT'ed code.
     Label header, footer;
     // If there aren't any arguments, don't do anything
     masm.ma_b(s0, reg_argv, &footer, Assembler::BelowOrEqual, ShortJump);
     {
         masm.bind(&header);
         masm.subPtr(Imm32(2 * sizeof(uintptr_t)), s0);
         masm.subPtr(Imm32(2 * sizeof(uintptr_t)), StackPointer);
         ValueOperand value = ValueOperand(s6, s7);
         masm.loadValue(Address(s0, 0), value);
         masm.storeValue(value, Address(StackPointer, 0));
         masm.ma_b(s0, reg_argv, &header, Assembler::Above, ShortJump);
     }
     masm.bind(&footer);
     masm.subPtr(Imm32(2 * sizeof(uintptr_t)), StackPointer);
     masm.storePtr(s3, Address(StackPointer, sizeof(uintptr_t))); // actual arguments
     masm.storePtr(s2, Address(StackPointer, 0)); // callee token
     masm.subPtr(StackPointer, s4);
     masm.makeFrameDescriptor(s4, JitFrame_Entry);
     masm.push(s4); // descriptor
     CodeLabel returnLabel;
     if (type == EnterJitBaseline) {
         // Handle OSR.
         GeneralRegisterSet regs(GeneralRegisterSet::All());
         regs.take(JSReturnOperand);
         regs.take(OsrFrameReg);
         regs.take(BaselineFrameReg);
         regs.take(reg_code);
         const Address slotNumStackValues(BaselineFrameReg, sizeof(EnterJITRegs) +
                                          offsetof(EnterJITArgs, numStackValues));
         const Address slotScopeChain(BaselineFrameReg, sizeof(EnterJITRegs) +
                                      offsetof(EnterJITArgs, scopeChain));
         Label notOsr;
         masm.ma_b(OsrFrameReg, OsrFrameReg, &notOsr, Assembler::Zero, ShortJump);
         Register scratch = regs.takeAny();
         Register numStackValues = regs.takeAny();
         masm.load32(slotNumStackValues, numStackValues);
         // Push return address, previous frame pointer.
         masm.subPtr(Imm32(2 * sizeof(uintptr_t)), StackPointer);
         masm.ma_li(scratch, returnLabel.dest());
         masm.storePtr(scratch, Address(StackPointer, sizeof(uintptr_t)));
         masm.storePtr(BaselineFrameReg, Address(StackPointer, 0));
         // Reserve frame.
         Register framePtr = BaselineFrameReg;
         masm.subPtr(Imm32(BaselineFrame::Size()), StackPointer);
         masm.movePtr(StackPointer, framePtr);
         // Reserve space for locals and stack values.
         masm.ma_sll(scratch, numStackValues, Imm32(3));
         masm.subPtr(scratch, StackPointer);
         // Enter exit frame.
         masm.addPtr(Imm32(BaselineFrame::Size() + BaselineFrame::FramePointerOffset), scratch);
         masm.makeFrameDescriptor(scratch, JitFrame_BaselineJS);
         // Push frame descriptor and fake return address.
         masm.reserveStack(2 * sizeof(uintptr_t));
         masm.storePtr(scratch, Address(StackPointer, sizeof(uintptr_t))); // Frame descriptor
         masm.storePtr(zero, Address(StackPointer, 0)); // fake return address
         masm.enterFakeExitFrame();
         masm.reserveStack(2 * sizeof(uintptr_t));
         masm.storePtr(framePtr, Address(StackPointer, sizeof(uintptr_t))); // BaselineFrame
         masm.storePtr(reg_code, Address(StackPointer, 0)); // jitcode
         masm.setupUnalignedABICall(3, scratch);
         masm.passABIArg(BaselineFrameReg); // BaselineFrame
         masm.passABIArg(OsrFrameReg); // InterpreterFrame
         masm.passABIArg(numStackValues);
         masm.callWithABI(JS_FUNC_TO_DATA_PTR(void *, jit::InitBaselineFrameForOsr));
         Register jitcode = regs.takeAny();
         masm.loadPtr(Address(StackPointer, 0), jitcode);
         masm.loadPtr(Address(StackPointer, sizeof(uintptr_t)), framePtr);
         masm.freeStack(2 * sizeof(uintptr_t));
         MOZ_ASSERT(jitcode != ReturnReg);
         Label error;
         masm.freeStack(IonExitFrameLayout::SizeWithFooter());
         masm.addPtr(Imm32(BaselineFrame::Size()), framePtr);
         masm.branchIfFalseBool(ReturnReg, &error);
         masm.jump(jitcode);
         // OOM: load error value, discard return address and previous frame
         // pointer and return.
         masm.bind(&error);
         masm.movePtr(framePtr, StackPointer);
         masm.addPtr(Imm32(2 * sizeof(uintptr_t)), StackPointer);
         masm.moveValue(MagicValue(JS_ION_ERROR), JSReturnOperand);
         masm.ma_li(scratch, returnLabel.dest());
         masm.jump(scratch);
         masm.bind(&notOsr);
         // Load the scope chain in R1.
         MOZ_ASSERT(R1.scratchReg() != reg_code);
         masm.loadPtr(slotScopeChain, R1.scratchReg());
     }
     // Call the function with pushing return address to stack.
     masm.ma_callIonHalfPush(reg_code);
     if (type == EnterJitBaseline) {
         // Baseline OSR will return here.
         masm.bind(returnLabel.src());
         if (!masm.addCodeLabel(returnLabel))
             return nullptr;
     }
     // Pop arguments off the stack.
     // s0 <- 8*argc (size of all arguments we pushed on the stack)
     masm.pop(s0);
     masm.rshiftPtr(Imm32(4), s0);
     masm.addPtr(s0, StackPointer);
     // Store the returned value into the slotVp
     masm.loadPtr(slotVp, s1);
     masm.storeValue(JSReturnOperand, Address(s1, 0));
     // Restore non-volatile registers and return.
     GenerateReturn(masm, ShortJump);
     Linker linker(masm);
     AutoFlushICache afc("GenerateEnterJIT");
     JitCode *code = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(code, "EnterJIT");
 #endif
     return code;
 }
 JitCode *
 JitRuntime::generateInvalidator(JSContext *cx)
 {
     MacroAssembler masm(cx);
     // NOTE: Members ionScript_ and osiPointReturnAddress_ of
     // InvalidationBailoutStack are already on the stack.
     static const uint32_t STACK_DATA_SIZE = sizeof(InvalidationBailoutStack) -
 * sizeof(uintptr_t);
     // Stack has to be alligned here. If not, we will have to fix it.
     masm.checkStackAlignment();
     // Make room for data on stack.
     masm.subPtr(Imm32(STACK_DATA_SIZE), StackPointer);
     // Save general purpose registers
     for (uint32_t i = 0; i < Registers::Total; i++) {
         Address address = Address(StackPointer, InvalidationBailoutStack::offsetOfRegs() +
                                                 i * sizeof(uintptr_t));
         masm.storePtr(Register::FromCode(i), address);
     }
     // Save floating point registers
     // We can use as_sd because stack is alligned.
     for (uint32_t i = 0; i < FloatRegisters::Total; i++)
         masm.as_sd(FloatRegister::FromCode(i), StackPointer,
                    InvalidationBailoutStack::offsetOfFpRegs() + i * sizeof(double));
     // Pass pointer to InvalidationBailoutStack structure.
     masm.movePtr(StackPointer, a0);
     // Reserve place for return value and BailoutInfo pointer
     masm.subPtr(Imm32(2 * sizeof(uintptr_t)), StackPointer);
     // Pass pointer to return value.
     masm.ma_addu(a1, StackPointer, Imm32(sizeof(uintptr_t)));
     // Pass pointer to BailoutInfo
     masm.movePtr(StackPointer, a2);
     masm.setupAlignedABICall(3);
     masm.passABIArg(a0);
     masm.passABIArg(a1);
     masm.passABIArg(a2);
     masm.callWithABI(JS_FUNC_TO_DATA_PTR(void *, InvalidationBailout));
     masm.loadPtr(Address(StackPointer, 0), a2);
     masm.loadPtr(Address(StackPointer, sizeof(uintptr_t)), a1);
     // Remove the return address, the IonScript, the register state
     // (InvaliationBailoutStack) and the space that was allocated for the
     // return value.
     masm.addPtr(Imm32(sizeof(InvalidationBailoutStack) + 2 * sizeof(uintptr_t)), StackPointer);
     // remove the space that this frame was using before the bailout
     // (computed by InvalidationBailout)
     masm.addPtr(a1, StackPointer);
     // Jump to shared bailout tail. The BailoutInfo pointer has to be in r2.
     JitCode *bailoutTail = cx->runtime()->jitRuntime()->getBailoutTail();
     masm.branch(bailoutTail);
     Linker linker(masm);
     AutoFlushICache afc("Invalidator");
     JitCode *code = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
     IonSpew(IonSpew_Invalidate, "   invalidation thunk created at %p", (void *) code->raw());
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(code, "Invalidator");
 #endif
     return code;
 }
 JitCode *
 JitRuntime::generateArgumentsRectifier(JSContext *cx, ExecutionMode mode, void **returnAddrOut)
 {
     MacroAssembler masm(cx);
     // ArgumentsRectifierReg contains the |nargs| pushed onto the current
     // frame. Including |this|, there are (|nargs| + 1) arguments to copy.
     MOZ_ASSERT(ArgumentsRectifierReg == s3);
     Register numActArgsReg = t6;
     Register calleeTokenReg = t7;
     Register numArgsReg = t5;
     // Copy number of actual arguments into numActArgsReg
     masm.loadPtr(Address(StackPointer, IonRectifierFrameLayout::offsetOfNumActualArgs()),
                  numActArgsReg);
     // Load the number of |undefined|s to push into t1.
     masm.loadPtr(Address(StackPointer, IonRectifierFrameLayout::offsetOfCalleeToken()),
                  calleeTokenReg);
     masm.load16ZeroExtend(Address(calleeTokenReg, JSFunction::offsetOfNargs()), numArgsReg);
     masm.ma_subu(t1, numArgsReg, s3);
     masm.moveValue(UndefinedValue(), ValueOperand(t3, t4));
     masm.movePtr(StackPointer, t2); // Save %sp.
     // Push undefined.
     {
         Label undefLoopTop;
         masm.bind(&undefLoopTop);
         masm.subPtr(Imm32(sizeof(Value)), StackPointer);
         masm.storeValue(ValueOperand(t3, t4), Address(StackPointer, 0));
         masm.sub32(Imm32(1), t1);
         masm.ma_b(t1, t1, &undefLoopTop, Assembler::NonZero, ShortJump);
     }
     // Get the topmost argument.
     masm.ma_sll(t0, s3, Imm32(3)); // t0 <- nargs * 8
     masm.addPtr(t0, t2); // t2 <- t2(saved sp) + nargs * 8
     masm.addPtr(Imm32(sizeof(IonRectifierFrameLayout)), t2);
     // Push arguments, |nargs| + 1 times (to include |this|).
     {
         Label copyLoopTop, initialSkip;
         masm.ma_b(&initialSkip, ShortJump);
         masm.bind(&copyLoopTop);
         masm.subPtr(Imm32(sizeof(Value)), t2);
         masm.sub32(Imm32(1), s3);
         masm.bind(&initialSkip);
         MOZ_ASSERT(sizeof(Value) == 2 * sizeof(uint32_t));
         // Read argument and push to stack.
         masm.subPtr(Imm32(sizeof(Value)), StackPointer);
         masm.load32(Address(t2, NUNBOX32_TYPE_OFFSET), t0);
         masm.store32(t0, Address(StackPointer, NUNBOX32_TYPE_OFFSET));
         masm.load32(Address(t2, NUNBOX32_PAYLOAD_OFFSET), t0);
         masm.store32(t0, Address(StackPointer, NUNBOX32_PAYLOAD_OFFSET));
         masm.ma_b(s3, s3, &copyLoopTop, Assembler::NonZero, ShortJump);
     }
     // translate the framesize from values into bytes
     masm.ma_addu(t0, numArgsReg, Imm32(1));
     masm.lshiftPtr(Imm32(3), t0);
     // Construct sizeDescriptor.
     masm.makeFrameDescriptor(t0, JitFrame_Rectifier);
     // Construct IonJSFrameLayout.
     masm.subPtr(Imm32(3 * sizeof(uintptr_t)), StackPointer);
     // Push actual arguments.
     masm.storePtr(numActArgsReg, Address(StackPointer, 2 * sizeof(uintptr_t)));
     // Push callee token.
     masm.storePtr(calleeTokenReg, Address(StackPointer, sizeof(uintptr_t)));
     // Push frame descriptor.
     masm.storePtr(t0, Address(StackPointer, 0));
     // Call the target function.
     // Note that this code assumes the function is JITted.
     masm.loadPtr(Address(calleeTokenReg, JSFunction::offsetOfNativeOrScript()), t1);
     masm.loadBaselineOrIonRaw(t1, t1, mode, nullptr);
     masm.ma_callIonHalfPush(t1);
     uint32_t returnOffset = masm.currentOffset();
     // arg1
     //  ...
     // argN
     // num actual args
     // callee token
     // sizeDescriptor     <- sp now
     // return address
     // Remove the rectifier frame.
     // t0 <- descriptor with FrameType.
     masm.loadPtr(Address(StackPointer, 0), t0);
     masm.rshiftPtr(Imm32(FRAMESIZE_SHIFT), t0); // t0 <- descriptor.
     // Discard descriptor, calleeToken and number of actual arguments.
     masm.addPtr(Imm32(3 * sizeof(uintptr_t)), StackPointer);
     // arg1
     //  ...
     // argN               <- sp now; t0 <- frame descriptor
     // num actual args
     // callee token
     // sizeDescriptor
     // return address
     // Discard pushed arguments.
     masm.addPtr(t0, StackPointer);
     masm.ret();
     Linker linker(masm);
     AutoFlushICache afc("ArgumentsRectifier");
     JitCode *code = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
     CodeOffsetLabel returnLabel(returnOffset);
     returnLabel.fixup(&masm);
     if (returnAddrOut)
         *returnAddrOut = (void *) (code->raw() + returnLabel.offset());
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(code, "ArgumentsRectifier");
 #endif
     return code;
 }
 /* There are two different stack layouts when doing bailout. They are
  * represented via class BailoutStack.
  *
  * - First case is when bailout is done trough bailout table. In this case
  * table offset is stored in $ra (look at JitRuntime::generateBailoutTable())
  * and thunk code should save it on stack. In this case frameClassId_ cannot
  * be NO_FRAME_SIZE_CLASS_ID. Members snapshotOffset_ and padding_ are not on
  * the stack.
  *
  * - Other case is when bailout is done via out of line code (lazy bailout).
  * In this case frame size is stored in $ra (look at
  * CodeGeneratorMIPS::generateOutOfLineCode()) and thunk code should save it
  * on stack. Other difference is that members snapshotOffset_ and padding_ are
  * pushed to the stack by CodeGeneratorMIPS::visitOutOfLineBailout(). Field
  * frameClassId_ is forced to be NO_FRAME_SIZE_CLASS_ID
  * (See: JitRuntime::generateBailoutHandler).
  */
 static void
 GenerateBailoutThunk(JSContext *cx, MacroAssembler &masm, uint32_t frameClass)
 {
     // NOTE: Members snapshotOffset_ and padding_ of BailoutStack
     // are not stored in this function.
     static const uint32_t bailoutDataSize = sizeof(BailoutStack) - 2 * sizeof(uintptr_t);
     static const uint32_t bailoutInfoOutParamSize = 2 * sizeof(uintptr_t);
     // Make sure that alignment is proper.
     masm.checkStackAlignment();
     // Make room for data.
     masm.subPtr(Imm32(bailoutDataSize), StackPointer);
     // Save general purpose registers.
     for (uint32_t i = 0; i < Registers::Total; i++) {
         uint32_t off = BailoutStack::offsetOfRegs() + i * sizeof(uintptr_t);
         masm.storePtr(Register::FromCode(i), Address(StackPointer, off));
     }
     // Save floating point registers
     // We can use as_sd because stack is alligned.
     for (uintptr_t i = 0; i < FloatRegisters::Total; i++)
         masm.as_sd(FloatRegister::FromCode(i), StackPointer,
                    BailoutStack::offsetOfFpRegs() + i * sizeof(double));
     // Store the frameSize_ or tableOffset_ stored in ra
     // See: JitRuntime::generateBailoutTable()
     // See: CodeGeneratorMIPS::generateOutOfLineCode()
     masm.storePtr(ra, Address(StackPointer, BailoutStack::offsetOfFrameSize()));
     // Put frame class to stack
     masm.storePtr(ImmWord(frameClass), Address(StackPointer, BailoutStack::offsetOfFrameClass()));
     // Put pointer to BailoutStack as first argument to the Bailout()
     masm.movePtr(StackPointer, a0);
     // Put pointer to BailoutInfo
     masm.subPtr(Imm32(bailoutInfoOutParamSize), StackPointer);
     masm.storePtr(ImmPtr(nullptr), Address(StackPointer, 0));
     masm.movePtr(StackPointer, a1);
     masm.setupAlignedABICall(2);
     masm.passABIArg(a0);
     masm.passABIArg(a1);
     masm.callWithABI(JS_FUNC_TO_DATA_PTR(void *, Bailout));
     // Get BailoutInfo pointer
     masm.loadPtr(Address(StackPointer, 0), a2);
     // Remove both the bailout frame and the topmost Ion frame's stack.
     if (frameClass == NO_FRAME_SIZE_CLASS_ID) {
         // Load frameSize from stack
         masm.loadPtr(Address(StackPointer,
                              bailoutInfoOutParamSize + BailoutStack::offsetOfFrameSize()), a1);
         // Remove complete BailoutStack class and data after it
         masm.addPtr(Imm32(sizeof(BailoutStack) + bailoutInfoOutParamSize), StackPointer);
         // Remove frame size srom stack
         masm.addPtr(a1, StackPointer);
     } else {
         uint32_t frameSize = FrameSizeClass::FromClass(frameClass).frameSize();
         // Remove the data this fuction added and frame size.
         masm.addPtr(Imm32(bailoutDataSize + bailoutInfoOutParamSize + frameSize), StackPointer);
     }
     // Jump to shared bailout tail. The BailoutInfo pointer has to be in a2.
     JitCode *bailoutTail = cx->runtime()->jitRuntime()->getBailoutTail();
     masm.branch(bailoutTail);
 }
 JitCode *
 JitRuntime::generateBailoutTable(JSContext *cx, uint32_t frameClass)
 {
     MacroAssembler masm(cx);
     Label bailout;
     for (size_t i = 0; i < BAILOUT_TABLE_SIZE; i++) {
         // Calculate offset to the end of table
         int32_t offset = (BAILOUT_TABLE_SIZE - i) * BAILOUT_TABLE_ENTRY_SIZE;
         // We use the 'ra' as table offset later in GenerateBailoutThunk
         masm.as_bal(BOffImm16(offset));
         masm.nop();
     }
     masm.bind(&bailout);
     GenerateBailoutThunk(cx, masm, frameClass);
     Linker linker(masm);
     AutoFlushICache afc("BailoutTable");
     JitCode *code = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(code, "BailoutTable");
 #endif
     return code;
 }
 JitCode *
 JitRuntime::generateBailoutHandler(JSContext *cx)
 {
     MacroAssembler masm(cx);
     GenerateBailoutThunk(cx, masm, NO_FRAME_SIZE_CLASS_ID);
     Linker linker(masm);
     AutoFlushICache afc("BailoutHandler");
     JitCode *code = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(code, "BailoutHandler");
 #endif
     return code;
 }
 JitCode *
 JitRuntime::generateVMWrapper(JSContext *cx, const VMFunction &f)
 {
     MOZ_ASSERT(functionWrappers_);
     MOZ_ASSERT(functionWrappers_->initialized());
     VMWrapperMap::AddPtr p = functionWrappers_->lookupForAdd(&f);
     if (p)
         return p->value();
     MacroAssembler masm(cx);
     GeneralRegisterSet regs = GeneralRegisterSet(Register::Codes::WrapperMask);
     static_assert((Register::Codes::VolatileMask & ~Register::Codes::WrapperMask) == 0,
                   "Wrapper register set should be a superset of Volatile register set.");
     // The context is the first argument; a0 is the first argument register.
     Register cxreg = a0;
     regs.take(cxreg);
     // We're aligned to an exit frame, so link it up.
     masm.enterExitFrameAndLoadContext(&f, cxreg, regs.getAny(), f.executionMode);
     // Save the base of the argument set stored on the stack.
     Register argsBase = InvalidReg;
     if (f.explicitArgs) {
         argsBase = t1; // Use temporary register.
         regs.take(argsBase);
         masm.ma_addu(argsBase, StackPointer, Imm32(IonExitFrameLayout::SizeWithFooter()));
     }
     // Reserve space for the outparameter.
     Register outReg = InvalidReg;
     switch (f.outParam) {
       case Type_Value:
         outReg = t0; // Use temporary register.
         regs.take(outReg);
         // Value outparam has to be 8 byte aligned because the called
         // function can use sdc1 or ldc1 instructions to access it.
         masm.reserveStack((StackAlignment - sizeof(uintptr_t)) + sizeof(Value));
         masm.alignPointerUp(StackPointer, outReg, StackAlignment);
         break;
       case Type_Handle:
         outReg = t0;
         regs.take(outReg);
         if (f.outParamRootType == VMFunction::RootValue) {
             // Value outparam has to be 8 byte aligned because the called
             // function can use sdc1 or ldc1 instructions to access it.
             masm.reserveStack((StackAlignment - sizeof(uintptr_t)) + sizeof(Value));
             masm.alignPointerUp(StackPointer, outReg, StackAlignment);
             masm.storeValue(UndefinedValue(), Address(outReg, 0));
         }
         else {
             masm.PushEmptyRooted(f.outParamRootType);
             masm.movePtr(StackPointer, outReg);
         }
         break;
       case Type_Bool:
       case Type_Int32:
         MOZ_ASSERT(sizeof(uintptr_t) == sizeof(uint32_t));
       case Type_Pointer:
         outReg = t0;
         regs.take(outReg);
         masm.reserveStack(sizeof(uintptr_t));
         masm.movePtr(StackPointer, outReg);
         break;
       case Type_Double:
         outReg = t0;
         regs.take(outReg);
         // Double outparam has to be 8 byte aligned because the called
         // function can use sdc1 or ldc1 instructions to access it.
         masm.reserveStack((StackAlignment - sizeof(uintptr_t)) + sizeof(double));
         masm.alignPointerUp(StackPointer, outReg, StackAlignment);
         break;
       default:
         MOZ_ASSERT(f.outParam == Type_Void);
         break;
     }
     masm.setupUnalignedABICall(f.argc(), regs.getAny());
     masm.passABIArg(cxreg);
     size_t argDisp = 0;
     // Copy any arguments.
     for (uint32_t explicitArg = 0; explicitArg < f.explicitArgs; explicitArg++) {
         MoveOperand from;
         switch (f.argProperties(explicitArg)) {
           case VMFunction::WordByValue:
             masm.passABIArg(MoveOperand(argsBase, argDisp), MoveOp::GENERAL);
             argDisp += sizeof(uint32_t);
             break;
           case VMFunction::DoubleByValue:
             // Values should be passed by reference, not by value, so we
             // assert that the argument is a double-precision float.
             MOZ_ASSERT(f.argPassedInFloatReg(explicitArg));
             masm.passABIArg(MoveOperand(argsBase, argDisp), MoveOp::DOUBLE);
             argDisp += sizeof(double);
             break;
           case VMFunction::WordByRef:
             masm.passABIArg(MoveOperand(argsBase, argDisp, MoveOperand::EFFECTIVE_ADDRESS),
                             MoveOp::GENERAL);
             argDisp += sizeof(uint32_t);
             break;
           case VMFunction::DoubleByRef:
             masm.passABIArg(MoveOperand(argsBase, argDisp, MoveOperand::EFFECTIVE_ADDRESS),
                             MoveOp::GENERAL);
             argDisp += sizeof(double);
             break;
         }
     }
     // Copy the implicit outparam, if any.
     if (outReg != InvalidReg)
         masm.passABIArg(outReg);
     masm.callWithABI(f.wrapped);
     // Test for failure.
     switch (f.failType()) {
       case Type_Object:
         masm.branchTestPtr(Assembler::Zero, v0, v0, masm.failureLabel(f.executionMode));
         break;
       case Type_Bool:
         // Called functions return bools, which are 0/false and non-zero/true
         masm.branchIfFalseBool(v0, masm.failureLabel(f.executionMode));
         break;
       default:
         MOZ_ASSUME_UNREACHABLE("unknown failure kind");
     }
     // Load the outparam and free any allocated stack.
     switch (f.outParam) {
       case Type_Handle:
         if (f.outParamRootType == VMFunction::RootValue) {
             masm.alignPointerUp(StackPointer, SecondScratchReg, StackAlignment);
             masm.loadValue(Address(SecondScratchReg, 0), JSReturnOperand);
             masm.freeStack((StackAlignment - sizeof(uintptr_t)) + sizeof(Value));
         }
         else {
             masm.popRooted(f.outParamRootType, ReturnReg, JSReturnOperand);
         }
         break;
       case Type_Value:
         masm.alignPointerUp(StackPointer, SecondScratchReg, StackAlignment);
         masm.loadValue(Address(SecondScratchReg, 0), JSReturnOperand);
         masm.freeStack((StackAlignment - sizeof(uintptr_t)) + sizeof(Value));
         break;
       case Type_Int32:
         MOZ_ASSERT(sizeof(uintptr_t) == sizeof(uint32_t));
       case Type_Pointer:
         masm.load32(Address(StackPointer, 0), ReturnReg);
         masm.freeStack(sizeof(uintptr_t));
         break;
       case Type_Bool:
         masm.load8ZeroExtend(Address(StackPointer, 0), ReturnReg);
         masm.freeStack(sizeof(uintptr_t));
         break;
       case Type_Double:
         if (cx->runtime()->jitSupportsFloatingPoint) {
             masm.alignPointerUp(StackPointer, SecondScratchReg, StackAlignment);
             // Address is aligned, so we can use as_ld.
             masm.as_ld(ReturnFloatReg, SecondScratchReg, 0);
         } else {
             masm.assumeUnreachable("Unable to load into float reg, with no FP support.");
         }
         masm.freeStack((StackAlignment - sizeof(uintptr_t)) + sizeof(double));
         break;
       default:
         MOZ_ASSERT(f.outParam == Type_Void);
         break;
     }
     masm.leaveExitFrame();
     masm.retn(Imm32(sizeof(IonExitFrameLayout) +
                     f.explicitStackSlots() * sizeof(uintptr_t) +
                     f.extraValuesToPop * sizeof(Value)));
     Linker linker(masm);
     AutoFlushICache afc("VMWrapper");
     JitCode *wrapper = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
     if (!wrapper)
         return nullptr;
     // linker.newCode may trigger a GC and sweep functionWrappers_ so we have
     // to use relookupOrAdd instead of add.
     if (!functionWrappers_->relookupOrAdd(p, &f, wrapper))
         return nullptr;
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(wrapper, "VMWrapper");
 #endif
     return wrapper;
 }
 JitCode *
 JitRuntime::generatePreBarrier(JSContext *cx, MIRType type)
 {
     MacroAssembler masm(cx);
     RegisterSet save;
     if (cx->runtime()->jitSupportsFloatingPoint) {
         save = RegisterSet(GeneralRegisterSet(Registers::VolatileMask),
                            FloatRegisterSet(FloatRegisters::VolatileMask));
     } else {
         save = RegisterSet(GeneralRegisterSet(Registers::VolatileMask),
                            FloatRegisterSet());
     }
     masm.PushRegsInMask(save);
     MOZ_ASSERT(PreBarrierReg == a1);
     masm.movePtr(ImmPtr(cx->runtime()), a0);
     masm.setupUnalignedABICall(2, a2);
     masm.passABIArg(a0);
     masm.passABIArg(a1);
     if (type == MIRType_Value) {
         masm.callWithABI(JS_FUNC_TO_DATA_PTR(void *, MarkValueFromIon));
     } else {
         MOZ_ASSERT(type == MIRType_Shape);
         masm.callWithABI(JS_FUNC_TO_DATA_PTR(void *, MarkShapeFromIon));
     }
     masm.PopRegsInMask(save);
     masm.ret();
     Linker linker(masm);
     AutoFlushICache afc("PreBarrier");
     JitCode *code = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(code, "PreBarrier");
 #endif
     return code;
 }
 typedef bool (*HandleDebugTrapFn)(JSContext *, BaselineFrame *, uint8_t *, bool *);
 static const VMFunction HandleDebugTrapInfo = FunctionInfo<HandleDebugTrapFn>(HandleDebugTrap);
 JitCode *
 JitRuntime::generateDebugTrapHandler(JSContext *cx)
 {
     MacroAssembler masm(cx);
     Register scratch1 = t0;
     Register scratch2 = t1;
     // Load BaselineFrame pointer in scratch1.
     masm.movePtr(s5, scratch1);
     masm.subPtr(Imm32(BaselineFrame::Size()), scratch1);
     // Enter a stub frame and call the HandleDebugTrap VM function. Ensure
     // the stub frame has a nullptr ICStub pointer, since this pointer is
     // marked during GC.
     masm.movePtr(ImmPtr(nullptr), BaselineStubReg);
     EmitEnterStubFrame(masm, scratch2);
     JitCode *code = cx->runtime()->jitRuntime()->getVMWrapper(HandleDebugTrapInfo);
     if (!code)
         return nullptr;
     masm.subPtr(Imm32(2 * sizeof(uintptr_t)), StackPointer);
     masm.storePtr(ra, Address(StackPointer, sizeof(uintptr_t)));
     masm.storePtr(scratch1, Address(StackPointer, 0));
     EmitCallVM(code, masm);
     EmitLeaveStubFrame(masm);
     // If the stub returns |true|, we have to perform a forced return
     // (return from the JS frame). If the stub returns |false|, just return
     // from the trap stub so that execution continues at the current pc.
     Label forcedReturn;
     masm.branchTest32(Assembler::NonZero, ReturnReg, ReturnReg, &forcedReturn);
     // ra was restored by EmitLeaveStubFrame
     masm.branch(ra);
     masm.bind(&forcedReturn);
     masm.loadValue(Address(s5, BaselineFrame::reverseOffsetOfReturnValue()),
                    JSReturnOperand);
     masm.movePtr(s5, StackPointer);
     masm.pop(s5);
     masm.ret();
     Linker linker(masm);
     AutoFlushICache afc("DebugTrapHandler");
     JitCode *codeDbg = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(codeDbg, "DebugTrapHandler");
 #endif
     return codeDbg;
 }
 JitCode *
 JitRuntime::generateExceptionTailStub(JSContext *cx)
 {
     MacroAssembler masm;
     masm.handleFailureWithHandlerTail();
     Linker linker(masm);
     AutoFlushICache afc("ExceptionTailStub");
     JitCode *code = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(code, "ExceptionTailStub");
 #endif
     return code;
 }
 JitCode *
 JitRuntime::generateBailoutTailStub(JSContext *cx)
 {
     MacroAssembler masm;
     masm.generateBailoutTail(a1, a2);
     Linker linker(masm);
     AutoFlushICache afc("BailoutTailStub");
     JitCode *code = linker.newCode<NoGC>(cx, JSC::OTHER_CODE);
 #ifdef JS_ION_PERF
     writePerfSpewerJitCodeProfile(code, "BailoutTailStub");
 #endif
     return code;
 }

The Tor Browser / annotate

js/src/jit/mips/Trampoline-mips.cpp@129ffea94266 (annotated)

js/src/jit/mips/Trampoline-mips.cpp