The Tor Browser: js/src/jit/mips/CodeGenerator-mips.cpp@b8a032363ba2 (annotated)

js/src/jit/mips/CodeGenerator-mips.cpp@b8a032363ba2 (annotated)

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

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- 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 "jit/mips/CodeGenerator-mips.h"
 #include "mozilla/MathAlgorithms.h"
 #include "jscntxt.h"
 #include "jscompartment.h"
 #include "jsnum.h"
 #include "jit/CodeGenerator.h"
 #include "jit/IonFrames.h"
 #include "jit/JitCompartment.h"
 #include "jit/MIR.h"
 #include "jit/MIRGraph.h"
 #include "vm/Shape.h"
 #include "jsscriptinlines.h"
 #include "jit/shared/CodeGenerator-shared-inl.h"
 using namespace js;
 using namespace js::jit;
 using mozilla::FloorLog2;
 using mozilla::NegativeInfinity;
 using JS::GenericNaN;
 // shared
 CodeGeneratorMIPS::CodeGeneratorMIPS(MIRGenerator *gen, LIRGraph *graph, MacroAssembler *masm)
   : CodeGeneratorShared(gen, graph, masm)
 {
 }
 bool
 CodeGeneratorMIPS::generatePrologue()
 {
     if (gen->compilingAsmJS()) {
         masm.Push(ra);
         // Note that this automatically sets MacroAssembler::framePushed().
         masm.reserveStack(frameDepth_);
     } else {
         // Note that this automatically sets MacroAssembler::framePushed().
         masm.reserveStack(frameSize());
         masm.checkStackAlignment();
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::generateEpilogue()
 {
     masm.bind(&returnLabel_);
 #if JS_TRACE_LOGGING
     masm.tracelogStop();
 #endif
     if (gen->compilingAsmJS()) {
         // Pop the stack we allocated at the start of the function.
         masm.freeStack(frameDepth_);
         masm.Pop(ra);
         masm.abiret();
         MOZ_ASSERT(masm.framePushed() == 0);
     } else {
         // Pop the stack we allocated at the start of the function.
         masm.freeStack(frameSize());
         MOZ_ASSERT(masm.framePushed() == 0);
         masm.ret();
     }
     return true;
 }
 void
 CodeGeneratorMIPS::branchToBlock(Assembler::FloatFormat fmt, FloatRegister lhs, FloatRegister rhs,
                                  MBasicBlock *mir, Assembler::DoubleCondition cond)
 {
     Label *label = mir->lir()->label();
     if (Label *oolEntry = labelForBackedgeWithImplicitCheck(mir)) {
         // Note: the backedge is initially a jump to the next instruction.
         // It will be patched to the target block's label during link().
         RepatchLabel rejoin;
         CodeOffsetJump backedge;
         Label skip;
         if (fmt == Assembler::DoubleFloat)
             masm.ma_bc1d(lhs, rhs, &skip, Assembler::InvertCondition(cond), ShortJump);
         else
             masm.ma_bc1s(lhs, rhs, &skip, Assembler::InvertCondition(cond), ShortJump);
         backedge = masm.jumpWithPatch(&rejoin);
         masm.bind(&rejoin);
         masm.bind(&skip);
         if (!patchableBackedges_.append(PatchableBackedgeInfo(backedge, label, oolEntry)))
             MOZ_CRASH();
     } else {
         if (fmt == Assembler::DoubleFloat)
             masm.branchDouble(cond, lhs, rhs, mir->lir()->label());
         else
             masm.branchFloat(cond, lhs, rhs, mir->lir()->label());
     }
 }
 bool
 OutOfLineBailout::accept(CodeGeneratorMIPS *codegen)
 {
     return codegen->visitOutOfLineBailout(this);
 }
 bool
 CodeGeneratorMIPS::visitTestIAndBranch(LTestIAndBranch *test)
 {
     const LAllocation *opd = test->getOperand(0);
     MBasicBlock *ifTrue = test->ifTrue();
     MBasicBlock *ifFalse = test->ifFalse();
     emitBranch(ToRegister(opd), Imm32(0), Assembler::NonZero, ifTrue, ifFalse);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompare(LCompare *comp)
 {
     Assembler::Condition cond = JSOpToCondition(comp->mir()->compareType(), comp->jsop());
     const LAllocation *left = comp->getOperand(0);
     const LAllocation *right = comp->getOperand(1);
     const LDefinition *def = comp->getDef(0);
     if (right->isConstant())
         masm.cmp32Set(cond, ToRegister(left), Imm32(ToInt32(right)), ToRegister(def));
     else if (right->isGeneralReg())
         masm.cmp32Set(cond, ToRegister(left), ToRegister(right), ToRegister(def));
     else
         masm.cmp32Set(cond, ToRegister(left), ToAddress(right), ToRegister(def));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareAndBranch(LCompareAndBranch *comp)
 {
     Assembler::Condition cond = JSOpToCondition(comp->cmpMir()->compareType(), comp->jsop());
     if (comp->right()->isConstant()) {
         emitBranch(ToRegister(comp->left()), Imm32(ToInt32(comp->right())), cond,
                    comp->ifTrue(), comp->ifFalse());
     } else if (comp->right()->isGeneralReg()) {
         emitBranch(ToRegister(comp->left()), ToRegister(comp->right()), cond,
                    comp->ifTrue(), comp->ifFalse());
     } else {
         emitBranch(ToRegister(comp->left()), ToAddress(comp->right()), cond,
                    comp->ifTrue(), comp->ifFalse());
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::generateOutOfLineCode()
 {
     if (!CodeGeneratorShared::generateOutOfLineCode())
         return false;
     if (deoptLabel_.used()) {
         // All non-table-based bailouts will go here.
         masm.bind(&deoptLabel_);
         // Push the frame size, so the handler can recover the IonScript.
         // Frame size is stored in 'ra' and pushed by GenerateBailoutThunk
         // We have to use 'ra' because generateBailoutTable will implicitly do
         // the same.
         masm.move32(Imm32(frameSize()), ra);
         JitCode *handler = gen->jitRuntime()->getGenericBailoutHandler();
         masm.branch(handler);
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::bailoutFrom(Label *label, LSnapshot *snapshot)
 {
     if (masm.bailed())
         return false;
     MOZ_ASSERT(label->used());
     MOZ_ASSERT(!label->bound());
     CompileInfo &info = snapshot->mir()->block()->info();
     switch (info.executionMode()) {
       case ParallelExecution: {
         // in parallel mode, make no attempt to recover, just signal an error.
         OutOfLineAbortPar *ool = oolAbortPar(ParallelBailoutUnsupported,
                                              snapshot->mir()->block(),
                                              snapshot->mir()->pc());
         masm.retarget(label, ool->entry());
         return true;
       }
       case SequentialExecution:
         break;
       default:
         MOZ_ASSUME_UNREACHABLE("No such execution mode");
     }
     if (!encode(snapshot))
         return false;
     // Though the assembler doesn't track all frame pushes, at least make sure
     // the known value makes sense. We can't use bailout tables if the stack
     // isn't properly aligned to the static frame size.
     MOZ_ASSERT_IF(frameClass_ != FrameSizeClass::None(),
                   frameClass_.frameSize() == masm.framePushed());
     // We don't use table bailouts because retargeting is easier this way.
     OutOfLineBailout *ool = new(alloc()) OutOfLineBailout(snapshot, masm.framePushed());
     if (!addOutOfLineCode(ool)) {
         return false;
     }
     masm.retarget(label, ool->entry());
     return true;
 }
 bool
 CodeGeneratorMIPS::bailout(LSnapshot *snapshot)
 {
     Label label;
     masm.jump(&label);
     return bailoutFrom(&label, snapshot);
 }
 bool
 CodeGeneratorMIPS::visitOutOfLineBailout(OutOfLineBailout *ool)
 {
     // Push snapshotOffset and make sure stack is aligned.
     masm.subPtr(Imm32(2 * sizeof(void *)), StackPointer);
     masm.storePtr(ImmWord(ool->snapshot()->snapshotOffset()), Address(StackPointer, 0));
     masm.jump(&deoptLabel_);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitMinMaxD(LMinMaxD *ins)
 {
     FloatRegister first = ToFloatRegister(ins->first());
     FloatRegister second = ToFloatRegister(ins->second());
     FloatRegister output = ToFloatRegister(ins->output());
     MOZ_ASSERT(first == output);
     Assembler::DoubleCondition cond = ins->mir()->isMax()
                                       ? Assembler::DoubleLessThanOrEqual
                                       : Assembler::DoubleGreaterThanOrEqual;
     Label nan, equal, returnSecond, done;
     // First or second is NaN, result is NaN.
     masm.ma_bc1d(first, second, &nan, Assembler::DoubleUnordered, ShortJump);
     // Make sure we handle -0 and 0 right.
     masm.ma_bc1d(first, second, &equal, Assembler::DoubleEqual, ShortJump);
     masm.ma_bc1d(first, second, &returnSecond, cond, ShortJump);
     masm.ma_b(&done, ShortJump);
     // Check for zero.
     masm.bind(&equal);
     masm.loadConstantDouble(0.0, ScratchFloatReg);
     // First wasn't 0 or -0, so just return it.
     masm.ma_bc1d(first, ScratchFloatReg, &done, Assembler::DoubleNotEqualOrUnordered, ShortJump);
     // So now both operands are either -0 or 0.
     if (ins->mir()->isMax()) {
         // -0 + -0 = -0 and -0 + 0 = 0.
         masm.addDouble(second, first);
     } else {
         masm.negateDouble(first);
         masm.subDouble(second, first);
         masm.negateDouble(first);
     }
     masm.ma_b(&done, ShortJump);
     masm.bind(&nan);
     masm.loadConstantDouble(GenericNaN(), output);
     masm.ma_b(&done, ShortJump);
     masm.bind(&returnSecond);
     masm.moveDouble(second, output);
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAbsD(LAbsD *ins)
 {
     FloatRegister input = ToFloatRegister(ins->input());
     MOZ_ASSERT(input == ToFloatRegister(ins->output()));
     masm.as_absd(input, input);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAbsF(LAbsF *ins)
 {
     FloatRegister input = ToFloatRegister(ins->input());
     MOZ_ASSERT(input == ToFloatRegister(ins->output()));
     masm.as_abss(input, input);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitSqrtD(LSqrtD *ins)
 {
     FloatRegister input = ToFloatRegister(ins->input());
     FloatRegister output = ToFloatRegister(ins->output());
     masm.as_sqrtd(output, input);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitSqrtF(LSqrtF *ins)
 {
     FloatRegister input = ToFloatRegister(ins->input());
     FloatRegister output = ToFloatRegister(ins->output());
     masm.as_sqrts(output, input);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAddI(LAddI *ins)
 {
     const LAllocation *lhs = ins->getOperand(0);
     const LAllocation *rhs = ins->getOperand(1);
     const LDefinition *dest = ins->getDef(0);
     MOZ_ASSERT(rhs->isConstant() || rhs->isGeneralReg());
     // If there is no snapshot, we don't need to check for overflow
     if (!ins->snapshot()) {
         if (rhs->isConstant())
             masm.ma_addu(ToRegister(dest), ToRegister(lhs), Imm32(ToInt32(rhs)));
         else
             masm.as_addu(ToRegister(dest), ToRegister(lhs), ToRegister(rhs));
         return true;
     }
     Label overflow;
     if (rhs->isConstant())
         masm.ma_addTestOverflow(ToRegister(dest), ToRegister(lhs), Imm32(ToInt32(rhs)), &overflow);
     else
         masm.ma_addTestOverflow(ToRegister(dest), ToRegister(lhs), ToRegister(rhs), &overflow);
     if (!bailoutFrom(&overflow, ins->snapshot()))
         return false;
     return true;
 }
 bool
 CodeGeneratorMIPS::visitSubI(LSubI *ins)
 {
     const LAllocation *lhs = ins->getOperand(0);
     const LAllocation *rhs = ins->getOperand(1);
     const LDefinition *dest = ins->getDef(0);
     MOZ_ASSERT(rhs->isConstant() || rhs->isGeneralReg());
     // If there is no snapshot, we don't need to check for overflow
     if (!ins->snapshot()) {
         if (rhs->isConstant())
             masm.ma_subu(ToRegister(dest), ToRegister(lhs), Imm32(ToInt32(rhs)));
         else
             masm.as_subu(ToRegister(dest), ToRegister(lhs), ToRegister(rhs));
         return true;
     }
     Label overflow;
     if (rhs->isConstant())
         masm.ma_subTestOverflow(ToRegister(dest), ToRegister(lhs), Imm32(ToInt32(rhs)), &overflow);
     else
         masm.ma_subTestOverflow(ToRegister(dest), ToRegister(lhs), ToRegister(rhs), &overflow);
     if (!bailoutFrom(&overflow, ins->snapshot()))
         return false;
     return true;
 }
 bool
 CodeGeneratorMIPS::visitMulI(LMulI *ins)
 {
     const LAllocation *lhs = ins->lhs();
     const LAllocation *rhs = ins->rhs();
     Register dest = ToRegister(ins->output());
     MMul *mul = ins->mir();
     MOZ_ASSERT_IF(mul->mode() == MMul::Integer, !mul->canBeNegativeZero() && !mul->canOverflow());
     if (rhs->isConstant()) {
         int32_t constant = ToInt32(rhs);
         Register src = ToRegister(lhs);
         // Bailout on -0.0
         if (mul->canBeNegativeZero() && constant <= 0) {
             Assembler::Condition cond = (constant == 0) ? Assembler::LessThan : Assembler::Equal;
             if (!bailoutCmp32(cond, src, Imm32(0), ins->snapshot()))
                 return false;
         }
         switch (constant) {
           case -1:
             if (mul->canOverflow()) {
                 if (!bailoutCmp32(Assembler::Equal, src, Imm32(INT32_MIN), ins->snapshot()))
                     return false;
             }
             masm.ma_negu(dest, src);
             break;
           case 0:
             masm.move32(Imm32(0), dest);
             break;
           case 1:
             masm.move32(src, dest);
             break;
           case 2:
             if (mul->canOverflow()) {
                 Label mulTwoOverflow;
                 masm.ma_addTestOverflow(dest, src, src, &mulTwoOverflow);
                 if (!bailoutFrom(&mulTwoOverflow, ins->snapshot()))
                     return false;
             } else {
                 masm.as_addu(dest, src, src);
             }
             break;
           default:
             uint32_t shift = FloorLog2(constant);
             if (!mul->canOverflow() && (constant > 0)) {
                 // If it cannot overflow, we can do lots of optimizations.
                 uint32_t rest = constant - (1 << shift);
                 // See if the constant has one bit set, meaning it can be
                 // encoded as a bitshift.
                 if ((1 << shift) == constant) {
                     masm.ma_sll(dest, src, Imm32(shift));
                     return true;
                 }
                 // If the constant cannot be encoded as (1<<C1), see if it can
                 // be encoded as (1<<C1) | (1<<C2), which can be computed
                 // using an add and a shift.
                 uint32_t shift_rest = FloorLog2(rest);
                 if (src != dest && (1u << shift_rest) == rest) {
                     masm.ma_sll(dest, src, Imm32(shift - shift_rest));
                     masm.add32(src, dest);
                     if (shift_rest != 0)
                         masm.ma_sll(dest, dest, Imm32(shift_rest));
                     return true;
                 }
             }
             if (mul->canOverflow() && (constant > 0) && (src != dest)) {
                 // To stay on the safe side, only optimize things that are a
                 // power of 2.
                 if ((1 << shift) == constant) {
                     // dest = lhs * pow(2, shift)
                     masm.ma_sll(dest, src, Imm32(shift));
                     // At runtime, check (lhs == dest >> shift), if this does
                     // not hold, some bits were lost due to overflow, and the
                     // computation should be resumed as a double.
                     masm.ma_sra(ScratchRegister, dest, Imm32(shift));
                     if (!bailoutCmp32(Assembler::NotEqual, src, ScratchRegister, ins->snapshot()))
                         return false;
                     return true;
                 }
             }
             if (mul->canOverflow()) {
                 Label mulConstOverflow;
                 masm.ma_mul_branch_overflow(dest, ToRegister(lhs), Imm32(ToInt32(rhs)),
                                             &mulConstOverflow);
                 if (!bailoutFrom(&mulConstOverflow, ins->snapshot()))
                     return false;
             } else {
                 masm.ma_mult(src, Imm32(ToInt32(rhs)));
                 masm.as_mflo(dest);
             }
             break;
         }
     } else {
         Label multRegOverflow;
         if (mul->canOverflow()) {
             masm.ma_mul_branch_overflow(dest, ToRegister(lhs), ToRegister(rhs), &multRegOverflow);
             if (!bailoutFrom(&multRegOverflow, ins->snapshot()))
                 return false;
         } else {
             masm.as_mult(ToRegister(lhs), ToRegister(rhs));
             masm.as_mflo(dest);
         }
         if (mul->canBeNegativeZero()) {
             Label done;
             masm.ma_b(dest, dest, &done, Assembler::NonZero, ShortJump);
             // Result is -0 if lhs or rhs is negative.
             // In that case result must be double value so bailout
             Register scratch = SecondScratchReg;
             masm.ma_or(scratch, ToRegister(lhs), ToRegister(rhs));
             if (!bailoutCmp32(Assembler::Signed, scratch, scratch, ins->snapshot()))
                 return false;
             masm.bind(&done);
         }
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitDivI(LDivI *ins)
 {
     // Extract the registers from this instruction
     Register lhs = ToRegister(ins->lhs());
     Register rhs = ToRegister(ins->rhs());
     Register dest = ToRegister(ins->output());
     Register temp = ToRegister(ins->getTemp(0));
     MDiv *mir = ins->mir();
     Label done;
     // Handle divide by zero.
     if (mir->canBeDivideByZero()) {
         if (mir->canTruncateInfinities()) {
             // Truncated division by zero is zero (Infinity|0 == 0)
             Label notzero;
             masm.ma_b(rhs, rhs, &notzero, Assembler::NonZero, ShortJump);
             masm.move32(Imm32(0), dest);
             masm.ma_b(&done, ShortJump);
             masm.bind(&notzero);
         } else {
             MOZ_ASSERT(mir->fallible());
             if (!bailoutCmp32(Assembler::Zero, rhs, rhs, ins->snapshot()))
                 return false;
         }
     }
     // Handle an integer overflow exception from -2147483648 / -1.
     if (mir->canBeNegativeOverflow()) {
         Label notMinInt;
         masm.move32(Imm32(INT32_MIN), temp);
         masm.ma_b(lhs, temp, &notMinInt, Assembler::NotEqual, ShortJump);
         masm.move32(Imm32(-1), temp);
         if (mir->canTruncateOverflow()) {
             // (-INT32_MIN)|0 == INT32_MIN
             Label skip;
             masm.ma_b(rhs, temp, &skip, Assembler::NotEqual, ShortJump);
             masm.move32(Imm32(INT32_MIN), dest);
             masm.ma_b(&done, ShortJump);
             masm.bind(&skip);
         } else {
             MOZ_ASSERT(mir->fallible());
             if (!bailoutCmp32(Assembler::Equal, rhs, temp, ins->snapshot()))
                 return false;
         }
         masm.bind(&notMinInt);
     }
     // Handle negative 0. (0/-Y)
     if (!mir->canTruncateNegativeZero() && mir->canBeNegativeZero()) {
         Label nonzero;
         masm.ma_b(lhs, lhs, &nonzero, Assembler::NonZero, ShortJump);
         if (!bailoutCmp32(Assembler::LessThan, rhs, Imm32(0), ins->snapshot()))
             return false;
         masm.bind(&nonzero);
     }
     // Note: above safety checks could not be verified as Ion seems to be
     // smarter and requires double arithmetic in such cases.
     // All regular. Lets call div.
     if (mir->canTruncateRemainder()) {
         masm.as_div(lhs, rhs);
         masm.as_mflo(dest);
     } else {
         MOZ_ASSERT(mir->fallible());
         Label remainderNonZero;
         masm.ma_div_branch_overflow(dest, lhs, rhs, &remainderNonZero);
         if (!bailoutFrom(&remainderNonZero, ins->snapshot()))
             return false;
     }
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitDivPowTwoI(LDivPowTwoI *ins)
 {
     Register lhs = ToRegister(ins->numerator());
     Register dest = ToRegister(ins->output());
     Register tmp = ToRegister(ins->getTemp(0));
     int32_t shift = ins->shift();
     if (shift != 0) {
         MDiv *mir = ins->mir();
         if (!mir->isTruncated()) {
             // If the remainder is going to be != 0, bailout since this must
             // be a double.
             masm.ma_sll(tmp, lhs, Imm32(32 - shift));
             if (!bailoutCmp32(Assembler::NonZero, tmp, tmp, ins->snapshot()))
                 return false;
         }
         if (!mir->canBeNegativeDividend()) {
             // Numerator is unsigned, so needs no adjusting. Do the shift.
             masm.ma_sra(dest, lhs, Imm32(shift));
             return true;
         }
         // Adjust the value so that shifting produces a correctly rounded result
         // when the numerator is negative. See 10-1 "Signed Division by a Known
         // Power of 2" in Henry S. Warren, Jr.'s Hacker's Delight.
         if (shift > 1) {
             masm.ma_sra(tmp, lhs, Imm32(31));
             masm.ma_srl(tmp, tmp, Imm32(32 - shift));
             masm.add32(lhs, tmp);
         } else {
             masm.ma_srl(tmp, lhs, Imm32(32 - shift));
             masm.add32(lhs, tmp);
         }
         // Do the shift.
         masm.ma_sra(dest, tmp, Imm32(shift));
     } else {
         masm.move32(lhs, dest);
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitModI(LModI *ins)
 {
     // Extract the registers from this instruction
     Register lhs = ToRegister(ins->lhs());
     Register rhs = ToRegister(ins->rhs());
     Register dest = ToRegister(ins->output());
     Register callTemp = ToRegister(ins->callTemp());
     MMod *mir = ins->mir();
     Label done, prevent;
     masm.move32(lhs, callTemp);
     // Prevent INT_MIN % -1;
     // The integer division will give INT_MIN, but we want -(double)INT_MIN.
     if (mir->canBeNegativeDividend()) {
         masm.ma_b(lhs, Imm32(INT_MIN), &prevent, Assembler::NotEqual, ShortJump);
         if (mir->isTruncated()) {
             // (INT_MIN % -1)|0 == 0
             Label skip;
             masm.ma_b(rhs, Imm32(-1), &skip, Assembler::NotEqual, ShortJump);
             masm.move32(Imm32(0), dest);
             masm.ma_b(&done, ShortJump);
             masm.bind(&skip);
         } else {
             MOZ_ASSERT(mir->fallible());
             if (!bailoutCmp32(Assembler::Equal, rhs, Imm32(-1), ins->snapshot()))
                 return false;
         }
         masm.bind(&prevent);
     }
     // 0/X (with X < 0) is bad because both of these values *should* be
     // doubles, and the result should be -0.0, which cannot be represented in
     // integers. X/0 is bad because it will give garbage (or abort), when it
     // should give either \infty, -\infty or NAN.
     // Prevent 0 / X (with X < 0) and X / 0
     // testing X / Y.  Compare Y with 0.
     // There are three cases: (Y < 0), (Y == 0) and (Y > 0)
     // If (Y < 0), then we compare X with 0, and bail if X == 0
     // If (Y == 0), then we simply want to bail.
     // if (Y > 0), we don't bail.
     if (mir->canBeDivideByZero()) {
         if (mir->isTruncated()) {
             Label skip;
             masm.ma_b(rhs, Imm32(0), &skip, Assembler::NotEqual, ShortJump);
             masm.move32(Imm32(0), dest);
             masm.ma_b(&done, ShortJump);
             masm.bind(&skip);
         } else {
             MOZ_ASSERT(mir->fallible());
             if (!bailoutCmp32(Assembler::Equal, rhs, Imm32(0), ins->snapshot()))
                 return false;
         }
     }
     if (mir->canBeNegativeDividend()) {
         Label notNegative;
         masm.ma_b(rhs, Imm32(0), &notNegative, Assembler::GreaterThan, ShortJump);
         if (mir->isTruncated()) {
             // NaN|0 == 0 and (0 % -X)|0 == 0
             Label skip;
             masm.ma_b(lhs, Imm32(0), &skip, Assembler::NotEqual, ShortJump);
             masm.move32(Imm32(0), dest);
             masm.ma_b(&done, ShortJump);
             masm.bind(&skip);
         } else {
             MOZ_ASSERT(mir->fallible());
             if (!bailoutCmp32(Assembler::Equal, lhs, Imm32(0), ins->snapshot()))
                 return false;
         }
         masm.bind(&notNegative);
     }
     masm.as_div(lhs, rhs);
     masm.as_mfhi(dest);
     // If X%Y == 0 and X < 0, then we *actually* wanted to return -0.0
     if (mir->canBeNegativeDividend()) {
         if (mir->isTruncated()) {
             // -0.0|0 == 0
         } else {
             MOZ_ASSERT(mir->fallible());
             // See if X < 0
             masm.ma_b(dest, Imm32(0), &done, Assembler::NotEqual, ShortJump);
             if (!bailoutCmp32(Assembler::Signed, callTemp, Imm32(0), ins->snapshot()))
                 return false;
         }
     }
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitModPowTwoI(LModPowTwoI *ins)
 {
     Register in = ToRegister(ins->getOperand(0));
     Register out = ToRegister(ins->getDef(0));
     MMod *mir = ins->mir();
     Label negative, done;
     masm.move32(in, out);
     masm.ma_b(in, in, &done, Assembler::Zero, ShortJump);
     // Switch based on sign of the lhs.
     // Positive numbers are just a bitmask
     masm.ma_b(in, in, &negative, Assembler::Signed, ShortJump);
     {
         masm.and32(Imm32((1 << ins->shift()) - 1), out);
         masm.ma_b(&done, ShortJump);
     }
     // Negative numbers need a negate, bitmask, negate
     {
         masm.bind(&negative);
         masm.neg32(out);
         masm.and32(Imm32((1 << ins->shift()) - 1), out);
         masm.neg32(out);
     }
     if (mir->canBeNegativeDividend()) {
         if (!mir->isTruncated()) {
             MOZ_ASSERT(mir->fallible());
             if (!bailoutCmp32(Assembler::Equal, out, zero, ins->snapshot()))
                 return false;
         } else {
             // -0|0 == 0
         }
     }
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitModMaskI(LModMaskI *ins)
 {
     Register src = ToRegister(ins->getOperand(0));
     Register dest = ToRegister(ins->getDef(0));
     Register tmp = ToRegister(ins->getTemp(0));
     MMod *mir = ins->mir();
     if (!mir->isTruncated() && mir->canBeNegativeDividend()) {
         MOZ_ASSERT(mir->fallible());
         Label bail;
         masm.ma_mod_mask(src, dest, tmp, ins->shift(), &bail);
         if (!bailoutFrom(&bail, ins->snapshot()))
             return false;
     } else {
         masm.ma_mod_mask(src, dest, tmp, ins->shift(), nullptr);
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitBitNotI(LBitNotI *ins)
 {
     const LAllocation *input = ins->getOperand(0);
     const LDefinition *dest = ins->getDef(0);
     MOZ_ASSERT(!input->isConstant());
     masm.ma_not(ToRegister(dest), ToRegister(input));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitBitOpI(LBitOpI *ins)
 {
     const LAllocation *lhs = ins->getOperand(0);
     const LAllocation *rhs = ins->getOperand(1);
     const LDefinition *dest = ins->getDef(0);
     // all of these bitops should be either imm32's, or integer registers.
     switch (ins->bitop()) {
       case JSOP_BITOR:
         if (rhs->isConstant())
             masm.ma_or(ToRegister(dest), ToRegister(lhs), Imm32(ToInt32(rhs)));
         else
             masm.ma_or(ToRegister(dest), ToRegister(lhs), ToRegister(rhs));
         break;
       case JSOP_BITXOR:
         if (rhs->isConstant())
             masm.ma_xor(ToRegister(dest), ToRegister(lhs), Imm32(ToInt32(rhs)));
         else
             masm.ma_xor(ToRegister(dest), ToRegister(lhs), ToRegister(rhs));
         break;
       case JSOP_BITAND:
         if (rhs->isConstant())
             masm.ma_and(ToRegister(dest), ToRegister(lhs), Imm32(ToInt32(rhs)));
         else
             masm.ma_and(ToRegister(dest), ToRegister(lhs), ToRegister(rhs));
         break;
       default:
         MOZ_ASSUME_UNREACHABLE("unexpected binary opcode");
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitShiftI(LShiftI *ins)
 {
     Register lhs = ToRegister(ins->lhs());
     const LAllocation *rhs = ins->rhs();
     Register dest = ToRegister(ins->output());
     if (rhs->isConstant()) {
         int32_t shift = ToInt32(rhs) & 0x1F;
         switch (ins->bitop()) {
           case JSOP_LSH:
             if (shift)
                 masm.ma_sll(dest, lhs, Imm32(shift));
             else
                 masm.move32(lhs, dest);
             break;
           case JSOP_RSH:
             if (shift)
                 masm.ma_sra(dest, lhs, Imm32(shift));
             else
                 masm.move32(lhs, dest);
             break;
           case JSOP_URSH:
             if (shift) {
                 masm.ma_srl(dest, lhs, Imm32(shift));
             } else {
                 // x >>> 0 can overflow.
                 masm.move32(lhs, dest);
                 if (ins->mir()->toUrsh()->fallible()) {
                     if (!bailoutCmp32(Assembler::LessThan, dest, Imm32(0), ins->snapshot()))
                         return false;
                 }
             }
             break;
           default:
             MOZ_ASSUME_UNREACHABLE("Unexpected shift op");
         }
     } else {
         // The shift amounts should be AND'ed into the 0-31 range
         masm.ma_and(dest, ToRegister(rhs), Imm32(0x1F));
         switch (ins->bitop()) {
           case JSOP_LSH:
             masm.ma_sll(dest, lhs, dest);
             break;
           case JSOP_RSH:
             masm.ma_sra(dest, lhs, dest);
             break;
           case JSOP_URSH:
             masm.ma_srl(dest, lhs, dest);
             if (ins->mir()->toUrsh()->fallible()) {
                 // x >>> 0 can overflow.
                 if (!bailoutCmp32(Assembler::LessThan, dest, Imm32(0), ins->snapshot()))
                     return false;
             }
             break;
           default:
             MOZ_ASSUME_UNREACHABLE("Unexpected shift op");
         }
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitUrshD(LUrshD *ins)
 {
     Register lhs = ToRegister(ins->lhs());
     Register temp = ToRegister(ins->temp());
     const LAllocation *rhs = ins->rhs();
     FloatRegister out = ToFloatRegister(ins->output());
     if (rhs->isConstant()) {
         masm.ma_srl(temp, lhs, Imm32(ToInt32(rhs)));
     } else {
         masm.ma_srl(temp, lhs, ToRegister(rhs));
     }
     masm.convertUInt32ToDouble(temp, out);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitPowHalfD(LPowHalfD *ins)
 {
     FloatRegister input = ToFloatRegister(ins->input());
     FloatRegister output = ToFloatRegister(ins->output());
     Label done, skip;
     // Masm.pow(-Infinity, 0.5) == Infinity.
     masm.loadConstantDouble(NegativeInfinity<double>(), ScratchFloatReg);
     masm.ma_bc1d(input, ScratchFloatReg, &skip, Assembler::DoubleNotEqualOrUnordered, ShortJump);
     masm.as_negd(output, ScratchFloatReg);
     masm.ma_b(&done, ShortJump);
     masm.bind(&skip);
     // Math.pow(-0, 0.5) == 0 == Math.pow(0, 0.5).
     // Adding 0 converts any -0 to 0.
     masm.loadConstantDouble(0.0, ScratchFloatReg);
     masm.as_addd(output, input, ScratchFloatReg);
     masm.as_sqrtd(output, output);
     masm.bind(&done);
     return true;
 }
 MoveOperand
 CodeGeneratorMIPS::toMoveOperand(const LAllocation *a) const
 {
     if (a->isGeneralReg())
         return MoveOperand(ToRegister(a));
     if (a->isFloatReg()) {
         return MoveOperand(ToFloatRegister(a));
     }
     MOZ_ASSERT((ToStackOffset(a) & 3) == 0);
     int32_t offset = ToStackOffset(a);
     // The way the stack slots work, we assume that everything from
     // depth == 0 downwards is writable. However, since our frame is included
     // in this, ensure that the frame gets skipped.
     if (gen->compilingAsmJS())
         offset -= AlignmentMidPrologue;
     return MoveOperand(StackPointer, offset);
 }
 class js::jit::OutOfLineTableSwitch : public OutOfLineCodeBase<CodeGeneratorMIPS>
 {
     MTableSwitch *mir_;
     CodeLabel jumpLabel_;
     bool accept(CodeGeneratorMIPS *codegen) {
         return codegen->visitOutOfLineTableSwitch(this);
     }
   public:
     OutOfLineTableSwitch(MTableSwitch *mir)
       : mir_(mir)
     {}
     MTableSwitch *mir() const {
         return mir_;
     }
     CodeLabel *jumpLabel() {
         return &jumpLabel_;
     }
 };
 bool
 CodeGeneratorMIPS::visitOutOfLineTableSwitch(OutOfLineTableSwitch *ool)
 {
     MTableSwitch *mir = ool->mir();
     masm.align(sizeof(void*));
     masm.bind(ool->jumpLabel()->src());
     if (!masm.addCodeLabel(*ool->jumpLabel()))
         return false;
     for (size_t i = 0; i < mir->numCases(); i++) {
         LBlock *caseblock = mir->getCase(i)->lir();
         Label *caseheader = caseblock->label();
         uint32_t caseoffset = caseheader->offset();
         // The entries of the jump table need to be absolute addresses and thus
         // must be patched after codegen is finished.
         CodeLabel cl;
         masm.ma_li(ScratchRegister, cl.dest());
         masm.branch(ScratchRegister);
         cl.src()->bind(caseoffset);
         if (!masm.addCodeLabel(cl))
             return false;
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::emitTableSwitchDispatch(MTableSwitch *mir, const Register &index,
                                            const Register &address)
 {
     Label *defaultcase = mir->getDefault()->lir()->label();
     // Lower value with low value
     if (mir->low() != 0)
         masm.subPtr(Imm32(mir->low()), index);
     // Jump to default case if input is out of range
     int32_t cases = mir->numCases();
     masm.branchPtr(Assembler::AboveOrEqual, index, ImmWord(cases), defaultcase);
     // To fill in the CodeLabels for the case entries, we need to first
     // generate the case entries (we don't yet know their offsets in the
     // instruction stream).
     OutOfLineTableSwitch *ool = new(alloc()) OutOfLineTableSwitch(mir);
     if (!addOutOfLineCode(ool))
         return false;
     // Compute the position where a pointer to the right case stands.
     masm.ma_li(address, ool->jumpLabel()->dest());
     masm.lshiftPtr(Imm32(4), index);
     masm.addPtr(index, address);
     masm.branch(address);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitMathD(LMathD *math)
 {
     const LAllocation *src1 = math->getOperand(0);
     const LAllocation *src2 = math->getOperand(1);
     const LDefinition *output = math->getDef(0);
     switch (math->jsop()) {
       case JSOP_ADD:
         masm.as_addd(ToFloatRegister(output), ToFloatRegister(src1), ToFloatRegister(src2));
         break;
       case JSOP_SUB:
         masm.as_subd(ToFloatRegister(output), ToFloatRegister(src1), ToFloatRegister(src2));
         break;
       case JSOP_MUL:
         masm.as_muld(ToFloatRegister(output), ToFloatRegister(src1), ToFloatRegister(src2));
         break;
       case JSOP_DIV:
         masm.as_divd(ToFloatRegister(output), ToFloatRegister(src1), ToFloatRegister(src2));
         break;
       default:
         MOZ_ASSUME_UNREACHABLE("unexpected opcode");
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitMathF(LMathF *math)
 {
     const LAllocation *src1 = math->getOperand(0);
     const LAllocation *src2 = math->getOperand(1);
     const LDefinition *output = math->getDef(0);
     switch (math->jsop()) {
       case JSOP_ADD:
         masm.as_adds(ToFloatRegister(output), ToFloatRegister(src1), ToFloatRegister(src2));
         break;
       case JSOP_SUB:
         masm.as_subs(ToFloatRegister(output), ToFloatRegister(src1), ToFloatRegister(src2));
         break;
       case JSOP_MUL:
         masm.as_muls(ToFloatRegister(output), ToFloatRegister(src1), ToFloatRegister(src2));
         break;
       case JSOP_DIV:
         masm.as_divs(ToFloatRegister(output), ToFloatRegister(src1), ToFloatRegister(src2));
         break;
       default:
         MOZ_ASSUME_UNREACHABLE("unexpected opcode");
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitFloor(LFloor *lir)
 {
     FloatRegister input = ToFloatRegister(lir->input());
     FloatRegister scratch = ScratchFloatReg;
     Register output = ToRegister(lir->output());
     Label skipCheck, done;
     // If Nan, 0 or -0 check for bailout
     masm.loadConstantDouble(0.0, scratch);
     masm.ma_bc1d(input, scratch, &skipCheck, Assembler::DoubleNotEqual, ShortJump);
     // If high part is not zero, it is NaN or -0, so we bail.
     masm.moveFromDoubleHi(input, SecondScratchReg);
     if (!bailoutCmp32(Assembler::NotEqual, SecondScratchReg, Imm32(0), lir->snapshot()))
         return false;
     // Input was zero, so return zero.
     masm.move32(Imm32(0), output);
     masm.ma_b(&done, ShortJump);
     masm.bind(&skipCheck);
     masm.as_floorwd(scratch, input);
     masm.moveFromDoubleLo(scratch, output);
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MIN), lir->snapshot()))
         return false;
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MAX), lir->snapshot()))
         return false;
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitFloorF(LFloorF *lir)
 {
     FloatRegister input = ToFloatRegister(lir->input());
     FloatRegister scratch = ScratchFloatReg;
     Register output = ToRegister(lir->output());
     Label skipCheck, done;
     // If Nan, 0 or -0 check for bailout
     masm.loadConstantFloat32(0.0, scratch);
     masm.ma_bc1s(input, scratch, &skipCheck, Assembler::DoubleNotEqual, ShortJump);
     // If binary value is not zero, it is NaN or -0, so we bail.
     masm.moveFromDoubleLo(input, SecondScratchReg);
     if (!bailoutCmp32(Assembler::NotEqual, SecondScratchReg, Imm32(0), lir->snapshot()))
         return false;
     // Input was zero, so return zero.
     masm.move32(Imm32(0), output);
     masm.ma_b(&done, ShortJump);
     masm.bind(&skipCheck);
     masm.as_floorws(scratch, input);
     masm.moveFromDoubleLo(scratch, output);
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MIN), lir->snapshot()))
         return false;
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MAX), lir->snapshot()))
         return false;
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitRound(LRound *lir)
 {
     FloatRegister input = ToFloatRegister(lir->input());
     FloatRegister temp = ToFloatRegister(lir->temp());
     FloatRegister scratch = ScratchFloatReg;
     Register output = ToRegister(lir->output());
     Label bail, negative, end, skipCheck;
     // Load 0.5 in the temp register.
     masm.loadConstantDouble(0.5, temp);
     // Branch to a slow path for negative inputs. Doesn't catch NaN or -0.
     masm.loadConstantDouble(0.0, scratch);
     masm.ma_bc1d(input, scratch, &negative, Assembler::DoubleLessThan, ShortJump);
     // If Nan, 0 or -0 check for bailout
     masm.ma_bc1d(input, scratch, &skipCheck, Assembler::DoubleNotEqual, ShortJump);
     // If high part is not zero, it is NaN or -0, so we bail.
     masm.moveFromDoubleHi(input, SecondScratchReg);
     if (!bailoutCmp32(Assembler::NotEqual, SecondScratchReg, Imm32(0), lir->snapshot()))
         return false;
     // Input was zero, so return zero.
     masm.move32(Imm32(0), output);
     masm.ma_b(&end, ShortJump);
     masm.bind(&skipCheck);
     masm.loadConstantDouble(0.5, scratch);
     masm.addDouble(input, scratch);
     masm.as_floorwd(scratch, scratch);
     masm.moveFromDoubleLo(scratch, output);
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MIN), lir->snapshot()))
         return false;
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MAX), lir->snapshot()))
         return false;
     masm.jump(&end);
     // Input is negative, but isn't -0.
     masm.bind(&negative);
     masm.addDouble(input, temp);
     // If input + 0.5 >= 0, input is a negative number >= -0.5 and the
     // result is -0.
     masm.branchDouble(Assembler::DoubleGreaterThanOrEqual, temp, scratch, &bail);
     if (!bailoutFrom(&bail, lir->snapshot()))
         return false;
     // Truncate and round toward zero.
     // This is off-by-one for everything but integer-valued inputs.
     masm.as_floorwd(scratch, temp);
     masm.moveFromDoubleLo(scratch, output);
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MIN), lir->snapshot()))
         return false;
     masm.bind(&end);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitRoundF(LRoundF *lir)
 {
     FloatRegister input = ToFloatRegister(lir->input());
     FloatRegister temp = ToFloatRegister(lir->temp());
     FloatRegister scratch = ScratchFloatReg;
     Register output = ToRegister(lir->output());
     Label bail, negative, end, skipCheck;
     // Load 0.5 in the temp register.
     masm.loadConstantFloat32(0.5, temp);
     // Branch to a slow path for negative inputs. Doesn't catch NaN or -0.
     masm.loadConstantFloat32(0.0, scratch);
     masm.ma_bc1s(input, scratch, &negative, Assembler::DoubleLessThan, ShortJump);
     // If Nan, 0 or -0 check for bailout
     masm.ma_bc1s(input, scratch, &skipCheck, Assembler::DoubleNotEqual, ShortJump);
     // If binary value is not zero, it is NaN or -0, so we bail.
     masm.moveFromFloat32(input, SecondScratchReg);
     if (!bailoutCmp32(Assembler::NotEqual, SecondScratchReg, Imm32(0), lir->snapshot()))
         return false;
     // Input was zero, so return zero.
     masm.move32(Imm32(0), output);
     masm.ma_b(&end, ShortJump);
     masm.bind(&skipCheck);
     masm.loadConstantFloat32(0.5, scratch);
     masm.as_adds(scratch, input, scratch);
     masm.as_floorws(scratch, scratch);
     masm.moveFromFloat32(scratch, output);
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MIN), lir->snapshot()))
         return false;
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MAX), lir->snapshot()))
         return false;
     masm.jump(&end);
     // Input is negative, but isn't -0.
     masm.bind(&negative);
     masm.as_adds(temp, input, temp);
     // If input + 0.5 >= 0, input is a negative number >= -0.5 and the
     // result is -0.
     masm.branchFloat(Assembler::DoubleGreaterThanOrEqual, temp, scratch, &bail);
     if (!bailoutFrom(&bail, lir->snapshot()))
         return false;
     // Truncate and round toward zero.
     // This is off-by-one for everything but integer-valued inputs.
     masm.as_floorws(scratch, temp);
     masm.moveFromFloat32(scratch, output);
     if (!bailoutCmp32(Assembler::Equal, output, Imm32(INT_MIN), lir->snapshot()))
         return false;
     masm.bind(&end);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitTruncateDToInt32(LTruncateDToInt32 *ins)
 {
     return emitTruncateDouble(ToFloatRegister(ins->input()), ToRegister(ins->output()));
 }
 bool
 CodeGeneratorMIPS::visitTruncateFToInt32(LTruncateFToInt32 *ins)
 {
     return emitTruncateFloat32(ToFloatRegister(ins->input()), ToRegister(ins->output()));
 }
 static const uint32_t FrameSizes[] = { 128, 256, 512, 1024 };
 FrameSizeClass
 FrameSizeClass::FromDepth(uint32_t frameDepth)
 {
     for (uint32_t i = 0; i < JS_ARRAY_LENGTH(FrameSizes); i++) {
         if (frameDepth < FrameSizes[i])
             return FrameSizeClass(i);
     }
     return FrameSizeClass::None();
 }
 FrameSizeClass
 FrameSizeClass::ClassLimit()
 {
     return FrameSizeClass(JS_ARRAY_LENGTH(FrameSizes));
 }
 uint32_t
 FrameSizeClass::frameSize() const
 {
     MOZ_ASSERT(class_ != NO_FRAME_SIZE_CLASS_ID);
     MOZ_ASSERT(class_ < JS_ARRAY_LENGTH(FrameSizes));
     return FrameSizes[class_];
 }
 ValueOperand
 CodeGeneratorMIPS::ToValue(LInstruction *ins, size_t pos)
 {
     Register typeReg = ToRegister(ins->getOperand(pos + TYPE_INDEX));
     Register payloadReg = ToRegister(ins->getOperand(pos + PAYLOAD_INDEX));
     return ValueOperand(typeReg, payloadReg);
 }
 ValueOperand
 CodeGeneratorMIPS::ToOutValue(LInstruction *ins)
 {
     Register typeReg = ToRegister(ins->getDef(TYPE_INDEX));
     Register payloadReg = ToRegister(ins->getDef(PAYLOAD_INDEX));
     return ValueOperand(typeReg, payloadReg);
 }
 ValueOperand
 CodeGeneratorMIPS::ToTempValue(LInstruction *ins, size_t pos)
 {
     Register typeReg = ToRegister(ins->getTemp(pos + TYPE_INDEX));
     Register payloadReg = ToRegister(ins->getTemp(pos + PAYLOAD_INDEX));
     return ValueOperand(typeReg, payloadReg);
 }
 bool
 CodeGeneratorMIPS::visitValue(LValue *value)
 {
     const ValueOperand out = ToOutValue(value);
     masm.moveValue(value->value(), out);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitBox(LBox *box)
 {
     const LDefinition *type = box->getDef(TYPE_INDEX);
     MOZ_ASSERT(!box->getOperand(0)->isConstant());
     // For NUNBOX32, the input operand and the output payload have the same
     // virtual register. All that needs to be written is the type tag for
     // the type definition.
     masm.move32(Imm32(MIRTypeToTag(box->type())), ToRegister(type));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitBoxFloatingPoint(LBoxFloatingPoint *box)
 {
     const LDefinition *payload = box->getDef(PAYLOAD_INDEX);
     const LDefinition *type = box->getDef(TYPE_INDEX);
     const LAllocation *in = box->getOperand(0);
     FloatRegister reg = ToFloatRegister(in);
     if (box->type() == MIRType_Float32) {
         masm.convertFloat32ToDouble(reg, ScratchFloatReg);
         reg = ScratchFloatReg;
     }
     masm.ma_mv(reg, ValueOperand(ToRegister(type), ToRegister(payload)));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitUnbox(LUnbox *unbox)
 {
     // Note that for unbox, the type and payload indexes are switched on the
     // inputs.
     MUnbox *mir = unbox->mir();
     Register type = ToRegister(unbox->type());
     if (mir->fallible()) {
         if (!bailoutCmp32(Assembler::NotEqual, type, Imm32(MIRTypeToTag(mir->type())),
                           unbox->snapshot()))
             return false;
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitDouble(LDouble *ins)
 {
     const LDefinition *out = ins->getDef(0);
     masm.loadConstantDouble(ins->getDouble(), ToFloatRegister(out));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitFloat32(LFloat32 *ins)
 {
     const LDefinition *out = ins->getDef(0);
     masm.loadConstantFloat32(ins->getFloat(), ToFloatRegister(out));
     return true;
 }
 Register
 CodeGeneratorMIPS::splitTagForTest(const ValueOperand &value)
 {
     return value.typeReg();
 }
 bool
 CodeGeneratorMIPS::visitTestDAndBranch(LTestDAndBranch *test)
 {
     FloatRegister input = ToFloatRegister(test->input());
     MBasicBlock *ifTrue = test->ifTrue();
     MBasicBlock *ifFalse = test->ifFalse();
     masm.loadConstantDouble(0.0, ScratchFloatReg);
     // If 0, or NaN, the result is false.
     if (isNextBlock(ifFalse->lir())) {
         branchToBlock(Assembler::DoubleFloat, input, ScratchFloatReg, ifTrue,
                       Assembler::DoubleNotEqual);
     } else {
         branchToBlock(Assembler::DoubleFloat, input, ScratchFloatReg, ifFalse,
                       Assembler::DoubleEqualOrUnordered);
         jumpToBlock(ifTrue);
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitTestFAndBranch(LTestFAndBranch *test)
 {
     FloatRegister input = ToFloatRegister(test->input());
     MBasicBlock *ifTrue = test->ifTrue();
     MBasicBlock *ifFalse = test->ifFalse();
     masm.loadConstantFloat32(0.0, ScratchFloatReg);
     // If 0, or NaN, the result is false.
     if (isNextBlock(ifFalse->lir())) {
         branchToBlock(Assembler::SingleFloat, input, ScratchFloatReg, ifTrue,
                       Assembler::DoubleNotEqual);
     } else {
         branchToBlock(Assembler::SingleFloat, input, ScratchFloatReg, ifFalse,
                       Assembler::DoubleEqualOrUnordered);
         jumpToBlock(ifTrue);
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareD(LCompareD *comp)
 {
     FloatRegister lhs = ToFloatRegister(comp->left());
     FloatRegister rhs = ToFloatRegister(comp->right());
     Register dest = ToRegister(comp->output());
     Assembler::DoubleCondition cond = JSOpToDoubleCondition(comp->mir()->jsop());
     masm.ma_cmp_set_double(dest, lhs, rhs, cond);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareF(LCompareF *comp)
 {
     FloatRegister lhs = ToFloatRegister(comp->left());
     FloatRegister rhs = ToFloatRegister(comp->right());
     Register dest = ToRegister(comp->output());
     Assembler::DoubleCondition cond = JSOpToDoubleCondition(comp->mir()->jsop());
     masm.ma_cmp_set_float32(dest, lhs, rhs, cond);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareDAndBranch(LCompareDAndBranch *comp)
 {
     FloatRegister lhs = ToFloatRegister(comp->left());
     FloatRegister rhs = ToFloatRegister(comp->right());
     Assembler::DoubleCondition cond = JSOpToDoubleCondition(comp->cmpMir()->jsop());
     MBasicBlock *ifTrue = comp->ifTrue();
     MBasicBlock *ifFalse = comp->ifFalse();
     if (isNextBlock(ifFalse->lir())) {
         branchToBlock(Assembler::DoubleFloat, lhs, rhs, ifTrue, cond);
     } else {
         branchToBlock(Assembler::DoubleFloat, lhs, rhs, ifFalse,
                       Assembler::InvertCondition(cond));
         jumpToBlock(ifTrue);
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareFAndBranch(LCompareFAndBranch *comp)
 {
     FloatRegister lhs = ToFloatRegister(comp->left());
     FloatRegister rhs = ToFloatRegister(comp->right());
     Assembler::DoubleCondition cond = JSOpToDoubleCondition(comp->cmpMir()->jsop());
     MBasicBlock *ifTrue = comp->ifTrue();
     MBasicBlock *ifFalse = comp->ifFalse();
     if (isNextBlock(ifFalse->lir())) {
         branchToBlock(Assembler::SingleFloat, lhs, rhs, ifTrue, cond);
     } else {
         branchToBlock(Assembler::SingleFloat, lhs, rhs, ifFalse,
                       Assembler::InvertCondition(cond));
         jumpToBlock(ifTrue);
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareB(LCompareB *lir)
 {
     MCompare *mir = lir->mir();
     const ValueOperand lhs = ToValue(lir, LCompareB::Lhs);
     const LAllocation *rhs = lir->rhs();
     const Register output = ToRegister(lir->output());
     MOZ_ASSERT(mir->jsop() == JSOP_STRICTEQ || mir->jsop() == JSOP_STRICTNE);
     Assembler::Condition cond = JSOpToCondition(mir->compareType(), mir->jsop());
     Label notBoolean, done;
     masm.branchTestBoolean(Assembler::NotEqual, lhs, &notBoolean);
     {
         if (rhs->isConstant())
             masm.cmp32Set(cond, lhs.payloadReg(), Imm32(rhs->toConstant()->toBoolean()), output);
         else
             masm.cmp32Set(cond, lhs.payloadReg(), ToRegister(rhs), output);
         masm.jump(&done);
     }
     masm.bind(&notBoolean);
     {
         masm.move32(Imm32(mir->jsop() == JSOP_STRICTNE), output);
     }
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareBAndBranch(LCompareBAndBranch *lir)
 {
     MCompare *mir = lir->cmpMir();
     const ValueOperand lhs = ToValue(lir, LCompareBAndBranch::Lhs);
     const LAllocation *rhs = lir->rhs();
     MOZ_ASSERT(mir->jsop() == JSOP_STRICTEQ || mir->jsop() == JSOP_STRICTNE);
     MBasicBlock *mirNotBoolean = (mir->jsop() == JSOP_STRICTEQ) ? lir->ifFalse() : lir->ifTrue();
     branchToBlock(lhs.typeReg(), ImmType(JSVAL_TYPE_BOOLEAN), mirNotBoolean, Assembler::NotEqual);
     Assembler::Condition cond = JSOpToCondition(mir->compareType(), mir->jsop());
     if (rhs->isConstant())
         emitBranch(lhs.payloadReg(), Imm32(rhs->toConstant()->toBoolean()), cond, lir->ifTrue(),
                    lir->ifFalse());
     else
         emitBranch(lhs.payloadReg(), ToRegister(rhs), cond, lir->ifTrue(), lir->ifFalse());
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareV(LCompareV *lir)
 {
     MCompare *mir = lir->mir();
     Assembler::Condition cond = JSOpToCondition(mir->compareType(), mir->jsop());
     const ValueOperand lhs = ToValue(lir, LCompareV::LhsInput);
     const ValueOperand rhs = ToValue(lir, LCompareV::RhsInput);
     const Register output = ToRegister(lir->output());
     MOZ_ASSERT(IsEqualityOp(mir->jsop()));
     Label notEqual, done;
     masm.ma_b(lhs.typeReg(), rhs.typeReg(), &notEqual, Assembler::NotEqual, ShortJump);
     {
         masm.cmp32Set(cond, lhs.payloadReg(), rhs.payloadReg(), output);
         masm.ma_b(&done, ShortJump);
     }
     masm.bind(&notEqual);
     {
         masm.move32(Imm32(cond == Assembler::NotEqual), output);
     }
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitCompareVAndBranch(LCompareVAndBranch *lir)
 {
     MCompare *mir = lir->cmpMir();
     Assembler::Condition cond = JSOpToCondition(mir->compareType(), mir->jsop());
     const ValueOperand lhs = ToValue(lir, LCompareVAndBranch::LhsInput);
     const ValueOperand rhs = ToValue(lir, LCompareVAndBranch::RhsInput);
     MOZ_ASSERT(mir->jsop() == JSOP_EQ || mir->jsop() == JSOP_STRICTEQ ||
                mir->jsop() == JSOP_NE || mir->jsop() == JSOP_STRICTNE);
     MBasicBlock *notEqual = (cond == Assembler::Equal) ? lir->ifFalse() : lir->ifTrue();
     branchToBlock(lhs.typeReg(), rhs.typeReg(), notEqual, Assembler::NotEqual);
     emitBranch(lhs.payloadReg(), rhs.payloadReg(), cond, lir->ifTrue(), lir->ifFalse());
     return true;
 }
 bool
 CodeGeneratorMIPS::visitBitAndAndBranch(LBitAndAndBranch *lir)
 {
     if (lir->right()->isConstant())
         masm.ma_and(ScratchRegister, ToRegister(lir->left()), Imm32(ToInt32(lir->right())));
     else
         masm.ma_and(ScratchRegister, ToRegister(lir->left()), ToRegister(lir->right()));
     emitBranch(ScratchRegister, ScratchRegister, Assembler::NonZero, lir->ifTrue(),
                lir->ifFalse());
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAsmJSUInt32ToDouble(LAsmJSUInt32ToDouble *lir)
 {
     masm.convertUInt32ToDouble(ToRegister(lir->input()), ToFloatRegister(lir->output()));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAsmJSUInt32ToFloat32(LAsmJSUInt32ToFloat32 *lir)
 {
     masm.convertUInt32ToFloat32(ToRegister(lir->input()), ToFloatRegister(lir->output()));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitNotI(LNotI *ins)
 {
     masm.cmp32Set(Assembler::Equal, ToRegister(ins->input()), Imm32(0),
                   ToRegister(ins->output()));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitNotD(LNotD *ins)
 {
     // Since this operation is not, we want to set a bit if
     // the double is falsey, which means 0.0, -0.0 or NaN.
     FloatRegister in = ToFloatRegister(ins->input());
     Register dest = ToRegister(ins->output());
     Label falsey, done;
     masm.loadConstantDouble(0.0, ScratchFloatReg);
     masm.ma_bc1d(in, ScratchFloatReg, &falsey, Assembler::DoubleEqualOrUnordered, ShortJump);
     masm.move32(Imm32(0), dest);
     masm.ma_b(&done, ShortJump);
     masm.bind(&falsey);
     masm.move32(Imm32(1), dest);
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitNotF(LNotF *ins)
 {
     // Since this operation is not, we want to set a bit if
     // the float32 is falsey, which means 0.0, -0.0 or NaN.
     FloatRegister in = ToFloatRegister(ins->input());
     Register dest = ToRegister(ins->output());
     Label falsey, done;
     masm.loadConstantFloat32(0.0, ScratchFloatReg);
     masm.ma_bc1s(in, ScratchFloatReg, &falsey, Assembler::DoubleEqualOrUnordered, ShortJump);
     masm.move32(Imm32(0), dest);
     masm.ma_b(&done, ShortJump);
     masm.bind(&falsey);
     masm.move32(Imm32(1), dest);
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitLoadSlotV(LLoadSlotV *load)
 {
     const ValueOperand out = ToOutValue(load);
     Register base = ToRegister(load->input());
     int32_t offset = load->mir()->slot() * sizeof(js::Value);
     masm.loadValue(Address(base, offset), out);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitLoadSlotT(LLoadSlotT *load)
 {
     Register base = ToRegister(load->input());
     int32_t offset = load->mir()->slot() * sizeof(js::Value);
     if (load->mir()->type() == MIRType_Double)
         masm.loadInt32OrDouble(Address(base, offset), ToFloatRegister(load->output()));
     else
         masm.load32(Address(base, offset + NUNBOX32_PAYLOAD_OFFSET), ToRegister(load->output()));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitStoreSlotT(LStoreSlotT *store)
 {
     Register base = ToRegister(store->slots());
     int32_t offset = store->mir()->slot() * sizeof(js::Value);
     const LAllocation *value = store->value();
     MIRType valueType = store->mir()->value()->type();
     if (store->mir()->needsBarrier())
         emitPreBarrier(Address(base, offset), store->mir()->slotType());
     if (valueType == MIRType_Double) {
         masm.storeDouble(ToFloatRegister(value), Address(base, offset));
         return true;
     }
     // Store the type tag if needed.
     if (valueType != store->mir()->slotType())
         masm.storeTypeTag(ImmType(ValueTypeFromMIRType(valueType)), Address(base, offset));
     // Store the payload.
     if (value->isConstant())
         masm.storePayload(*value->toConstant(), Address(base, offset));
     else
         masm.storePayload(ToRegister(value), Address(base, offset));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitLoadElementT(LLoadElementT *load)
 {
     Register base = ToRegister(load->elements());
     if (load->mir()->type() == MIRType_Double) {
         FloatRegister fpreg = ToFloatRegister(load->output());
         if (load->index()->isConstant()) {
             Address source(base, ToInt32(load->index()) * sizeof(Value));
             if (load->mir()->loadDoubles())
                 masm.loadDouble(source, fpreg);
             else
                 masm.loadInt32OrDouble(source, fpreg);
         } else {
             Register index = ToRegister(load->index());
             if (load->mir()->loadDoubles())
                 masm.loadDouble(BaseIndex(base, index, TimesEight), fpreg);
             else
                 masm.loadInt32OrDouble(base, index, fpreg);
         }
     } else {
         if (load->index()->isConstant()) {
             Address source(base, ToInt32(load->index()) * sizeof(Value));
             masm.load32(source, ToRegister(load->output()));
         } else {
             BaseIndex source(base, ToRegister(load->index()), TimesEight);
             masm.load32(source, ToRegister(load->output()));
         }
     }
     MOZ_ASSERT(!load->mir()->needsHoleCheck());
     return true;
 }
 void
 CodeGeneratorMIPS::storeElementTyped(const LAllocation *value, MIRType valueType,
                                      MIRType elementType, const Register &elements,
                                      const LAllocation *index)
 {
     if (index->isConstant()) {
         Address dest = Address(elements, ToInt32(index) * sizeof(Value));
         if (valueType == MIRType_Double) {
             masm.storeDouble(ToFloatRegister(value), Address(dest.base, dest.offset));
             return;
         }
         // Store the type tag if needed.
         if (valueType != elementType)
             masm.storeTypeTag(ImmType(ValueTypeFromMIRType(valueType)), dest);
         // Store the payload.
         if (value->isConstant())
             masm.storePayload(*value->toConstant(), dest);
         else
             masm.storePayload(ToRegister(value), dest);
     } else {
         Register indexReg = ToRegister(index);
         if (valueType == MIRType_Double) {
             masm.storeDouble(ToFloatRegister(value), BaseIndex(elements, indexReg, TimesEight));
             return;
         }
         // Store the type tag if needed.
         if (valueType != elementType)
             masm.storeTypeTag(ImmType(ValueTypeFromMIRType(valueType)), elements, indexReg);
         // Store the payload.
         if (value->isConstant())
             masm.storePayload(*value->toConstant(), elements, indexReg);
         else
             masm.storePayload(ToRegister(value), elements, indexReg);
     }
 }
 bool
 CodeGeneratorMIPS::visitGuardShape(LGuardShape *guard)
 {
     Register obj = ToRegister(guard->input());
     Register tmp = ToRegister(guard->tempInt());
     masm.loadPtr(Address(obj, JSObject::offsetOfShape()), tmp);
     return bailoutCmpPtr(Assembler::NotEqual, tmp, ImmGCPtr(guard->mir()->shape()),
                          guard->snapshot());
 }
 bool
 CodeGeneratorMIPS::visitGuardObjectType(LGuardObjectType *guard)
 {
     Register obj = ToRegister(guard->input());
     Register tmp = ToRegister(guard->tempInt());
     masm.loadPtr(Address(obj, JSObject::offsetOfType()), tmp);
     Assembler::Condition cond = guard->mir()->bailOnEquality()
                                 ? Assembler::Equal
                                 : Assembler::NotEqual;
     return bailoutCmpPtr(cond, tmp, ImmGCPtr(guard->mir()->typeObject()), guard->snapshot());
 }
 bool
 CodeGeneratorMIPS::visitGuardClass(LGuardClass *guard)
 {
     Register obj = ToRegister(guard->input());
     Register tmp = ToRegister(guard->tempInt());
     masm.loadObjClass(obj, tmp);
     if (!bailoutCmpPtr(Assembler::NotEqual, tmp, Imm32((uint32_t)guard->mir()->getClass()),
                        guard->snapshot()))
         return false;
     return true;
 }
 bool
 CodeGeneratorMIPS::visitImplicitThis(LImplicitThis *lir)
 {
     Register callee = ToRegister(lir->callee());
     const ValueOperand out = ToOutValue(lir);
     // The implicit |this| is always |undefined| if the function's environment
     // is the current global.
     masm.loadPtr(Address(callee, JSFunction::offsetOfEnvironment()), out.typeReg());
     GlobalObject *global = &gen->info().script()->global();
     // TODO: OOL stub path.
     if (!bailoutCmpPtr(Assembler::NotEqual, out.typeReg(), ImmGCPtr(global), lir->snapshot()))
         return false;
     masm.moveValue(UndefinedValue(), out);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitInterruptCheck(LInterruptCheck *lir)
 {
     OutOfLineCode *ool = oolCallVM(InterruptCheckInfo, lir, (ArgList()), StoreNothing());
     if (!ool)
         return false;
     masm.branch32(Assembler::NotEqual,
                   AbsoluteAddress(GetIonContext()->runtime->addressOfInterrupt()), Imm32(0),
                   ool->entry());
     masm.bind(ool->rejoin());
     return true;
 }
 bool
 CodeGeneratorMIPS::generateInvalidateEpilogue()
 {
     // Ensure that there is enough space in the buffer for the OsiPoint
     // patching to occur. Otherwise, we could overwrite the invalidation
     // epilogue.
     for (size_t i = 0; i < sizeof(void *); i += Assembler::nopSize())
         masm.nop();
     masm.bind(&invalidate_);
     // Push the return address of the point that we bailed out at to the stack
     masm.Push(ra);
     // Push the Ion script onto the stack (when we determine what that
     // pointer is).
     invalidateEpilogueData_ = masm.pushWithPatch(ImmWord(uintptr_t(-1)));
     JitCode *thunk = gen->jitRuntime()->getInvalidationThunk();
     masm.branch(thunk);
     // We should never reach this point in JIT code -- the invalidation thunk
     // should pop the invalidated JS frame and return directly to its caller.
     masm.assumeUnreachable("Should have returned directly to its caller instead of here.");
     return true;
 }
 void
 DispatchIonCache::initializeAddCacheState(LInstruction *ins, AddCacheState *addState)
 {
     // Can always use the scratch register on MIPS.
     addState->dispatchScratch = ScratchRegister;
 }
 bool
 CodeGeneratorMIPS::visitLoadTypedArrayElementStatic(LLoadTypedArrayElementStatic *ins)
 {
     MOZ_ASSUME_UNREACHABLE("NYI");
 }
 bool
 CodeGeneratorMIPS::visitStoreTypedArrayElementStatic(LStoreTypedArrayElementStatic *ins)
 {
     MOZ_ASSUME_UNREACHABLE("NYI");
 }
 bool
 CodeGeneratorMIPS::visitAsmJSLoadHeap(LAsmJSLoadHeap *ins)
 {
     const MAsmJSLoadHeap *mir = ins->mir();
     const LAllocation *ptr = ins->ptr();
     const LDefinition *out = ins->output();
     bool isSigned;
     int size;
     bool isFloat = false;
     switch (mir->viewType()) {
       case ArrayBufferView::TYPE_INT8:    isSigned = true;  size =  8; break;
       case ArrayBufferView::TYPE_UINT8:   isSigned = false; size =  8; break;
       case ArrayBufferView::TYPE_INT16:   isSigned = true;  size = 16; break;
       case ArrayBufferView::TYPE_UINT16:  isSigned = false; size = 16; break;
       case ArrayBufferView::TYPE_INT32:   isSigned = true;  size = 32; break;
       case ArrayBufferView::TYPE_UINT32:  isSigned = false; size = 32; break;
       case ArrayBufferView::TYPE_FLOAT64: isFloat  = true;  size = 64; break;
       case ArrayBufferView::TYPE_FLOAT32: isFloat  = true;  size = 32; break;
       default: MOZ_ASSUME_UNREACHABLE("unexpected array type");
     }
     if (ptr->isConstant()) {
         MOZ_ASSERT(mir->skipBoundsCheck());
         int32_t ptrImm = ptr->toConstant()->toInt32();
         MOZ_ASSERT(ptrImm >= 0);
         if (isFloat) {
             if (size == 32) {
                 masm.loadFloat32(Address(HeapReg, ptrImm), ToFloatRegister(out));
             } else {
                 masm.loadDouble(Address(HeapReg, ptrImm), ToFloatRegister(out));
             }
         }  else {
             masm.ma_load(ToRegister(out), Address(HeapReg, ptrImm),
                          static_cast<LoadStoreSize>(size), isSigned ? SignExtend : ZeroExtend);
         }
         return true;
     }
     Register ptrReg = ToRegister(ptr);
     if (mir->skipBoundsCheck()) {
         if (isFloat) {
             if (size == 32) {
                 masm.loadFloat32(BaseIndex(HeapReg, ptrReg, TimesOne), ToFloatRegister(out));
             } else {
                 masm.loadDouble(BaseIndex(HeapReg, ptrReg, TimesOne), ToFloatRegister(out));
             }
         } else {
             masm.ma_load(ToRegister(out), BaseIndex(HeapReg, ptrReg, TimesOne),
                          static_cast<LoadStoreSize>(size), isSigned ? SignExtend : ZeroExtend);
         }
         return true;
     }
     BufferOffset bo = masm.ma_BoundsCheck(ScratchRegister);
     Label outOfRange;
     Label done;
     masm.ma_b(ptrReg, ScratchRegister, &outOfRange, Assembler::AboveOrEqual, ShortJump);
     // Offset is ok, let's load value.
     if (isFloat) {
         if (size == 32)
             masm.loadFloat32(BaseIndex(HeapReg, ptrReg, TimesOne), ToFloatRegister(out));
         else
             masm.loadDouble(BaseIndex(HeapReg, ptrReg, TimesOne), ToFloatRegister(out));
     } else {
         masm.ma_load(ToRegister(out), BaseIndex(HeapReg, ptrReg, TimesOne),
                      static_cast<LoadStoreSize>(size), isSigned ? SignExtend : ZeroExtend);
     }
     masm.ma_b(&done, ShortJump);
     masm.bind(&outOfRange);
     // Offset is out of range. Load default values.
     if (isFloat) {
         if (size == 32)
             masm.convertDoubleToFloat32(NANReg, ToFloatRegister(out));
         else
             masm.moveDouble(NANReg, ToFloatRegister(out));
     } else {
         masm.move32(Imm32(0), ToRegister(out));
     }
     masm.bind(&done);
     return gen->noteHeapAccess(AsmJSHeapAccess(bo.getOffset()));
 }
 bool
 CodeGeneratorMIPS::visitAsmJSStoreHeap(LAsmJSStoreHeap *ins)
 {
     const MAsmJSStoreHeap *mir = ins->mir();
     const LAllocation *value = ins->value();
     const LAllocation *ptr = ins->ptr();
     bool isSigned;
     int size;
     bool isFloat = false;
     switch (mir->viewType()) {
       case ArrayBufferView::TYPE_INT8:    isSigned = true;  size = 8;  break;
       case ArrayBufferView::TYPE_UINT8:   isSigned = false; size = 8;  break;
       case ArrayBufferView::TYPE_INT16:   isSigned = true;  size = 16; break;
       case ArrayBufferView::TYPE_UINT16:  isSigned = false; size = 16; break;
       case ArrayBufferView::TYPE_INT32:   isSigned = true;  size = 32; break;
       case ArrayBufferView::TYPE_UINT32:  isSigned = false; size = 32; break;
       case ArrayBufferView::TYPE_FLOAT64: isFloat  = true;  size = 64; break;
       case ArrayBufferView::TYPE_FLOAT32: isFloat  = true;  size = 32; break;
       default: MOZ_ASSUME_UNREACHABLE("unexpected array type");
     }
     if (ptr->isConstant()) {
         MOZ_ASSERT(mir->skipBoundsCheck());
         int32_t ptrImm = ptr->toConstant()->toInt32();
         MOZ_ASSERT(ptrImm >= 0);
         if (isFloat) {
             if (size == 32) {
                 masm.storeFloat32(ToFloatRegister(value), Address(HeapReg, ptrImm));
             } else {
                 masm.storeDouble(ToFloatRegister(value), Address(HeapReg, ptrImm));
             }
         }  else {
             masm.ma_store(ToRegister(value), Address(HeapReg, ptrImm),
                           static_cast<LoadStoreSize>(size), isSigned ? SignExtend : ZeroExtend);
         }
         return true;
     }
     Register ptrReg = ToRegister(ptr);
     Address dstAddr(ptrReg, 0);
     if (mir->skipBoundsCheck()) {
         if (isFloat) {
             if (size == 32) {
                 masm.storeFloat32(ToFloatRegister(value), BaseIndex(HeapReg, ptrReg, TimesOne));
             } else
                 masm.storeDouble(ToFloatRegister(value), BaseIndex(HeapReg, ptrReg, TimesOne));
         } else {
             masm.ma_store(ToRegister(value), BaseIndex(HeapReg, ptrReg, TimesOne),
                           static_cast<LoadStoreSize>(size), isSigned ? SignExtend : ZeroExtend);
         }
         return true;
     }
     BufferOffset bo = masm.ma_BoundsCheck(ScratchRegister);
     Label rejoin;
     masm.ma_b(ptrReg, ScratchRegister, &rejoin, Assembler::AboveOrEqual, ShortJump);
     // Offset is ok, let's store value.
     if (isFloat) {
         if (size == 32) {
             masm.storeFloat32(ToFloatRegister(value), BaseIndex(HeapReg, ptrReg, TimesOne));
         } else
             masm.storeDouble(ToFloatRegister(value), BaseIndex(HeapReg, ptrReg, TimesOne));
     } else {
         masm.ma_store(ToRegister(value), BaseIndex(HeapReg, ptrReg, TimesOne),
                       static_cast<LoadStoreSize>(size), isSigned ? SignExtend : ZeroExtend);
     }
     masm.bind(&rejoin);
     return gen->noteHeapAccess(AsmJSHeapAccess(bo.getOffset()));
 }
 bool
 CodeGeneratorMIPS::visitAsmJSPassStackArg(LAsmJSPassStackArg *ins)
 {
     const MAsmJSPassStackArg *mir = ins->mir();
     if (ins->arg()->isConstant()) {
         masm.storePtr(ImmWord(ToInt32(ins->arg())), Address(StackPointer, mir->spOffset()));
     } else {
         if (ins->arg()->isGeneralReg()) {
             masm.storePtr(ToRegister(ins->arg()), Address(StackPointer, mir->spOffset()));
         } else {
             masm.storeDouble(ToFloatRegister(ins->arg()), Address(StackPointer, mir->spOffset()));
         }
     }
     return true;
 }
 bool
 CodeGeneratorMIPS::visitUDiv(LUDiv *ins)
 {
     Register lhs = ToRegister(ins->lhs());
     Register rhs = ToRegister(ins->rhs());
     Register output = ToRegister(ins->output());
     Label done;
     if (ins->mir()->canBeDivideByZero()) {
         if (ins->mir()->isTruncated()) {
             Label notzero;
             masm.ma_b(rhs, rhs, &notzero, Assembler::NonZero, ShortJump);
             masm.move32(Imm32(0), output);
             masm.ma_b(&done, ShortJump);
             masm.bind(&notzero);
         } else {
             MOZ_ASSERT(ins->mir()->fallible());
             if (!bailoutCmp32(Assembler::Equal, rhs, Imm32(0), ins->snapshot()))
                 return false;
         }
     }
     masm.as_divu(lhs, rhs);
     masm.as_mflo(output);
     if (!ins->mir()->isTruncated()) {
         if (!bailoutCmp32(Assembler::LessThan, output, Imm32(0), ins->snapshot()))
             return false;
     }
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitUMod(LUMod *ins)
 {
     Register lhs = ToRegister(ins->lhs());
     Register rhs = ToRegister(ins->rhs());
     Register output = ToRegister(ins->output());
     Label done;
     if (ins->mir()->canBeDivideByZero()) {
         if (ins->mir()->isTruncated()) {
             // Infinity|0 == 0
             Label notzero;
             masm.ma_b(rhs, rhs, &notzero, Assembler::NonZero, ShortJump);
             masm.move32(Imm32(0), output);
             masm.ma_b(&done, ShortJump);
             masm.bind(&notzero);
         } else {
             MOZ_ASSERT(ins->mir()->fallible());
             if (!bailoutCmp32(Assembler::Equal, rhs, Imm32(0), ins->snapshot()))
                 return false;
         }
     }
     masm.as_divu(lhs, rhs);
     masm.as_mfhi(output);
     if (!ins->mir()->isTruncated()) {
         if (!bailoutCmp32(Assembler::LessThan, output, Imm32(0), ins->snapshot()))
             return false;
     }
     masm.bind(&done);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitEffectiveAddress(LEffectiveAddress *ins)
 {
     const MEffectiveAddress *mir = ins->mir();
     Register base = ToRegister(ins->base());
     Register index = ToRegister(ins->index());
     Register output = ToRegister(ins->output());
     BaseIndex address(base, index, mir->scale(), mir->displacement());
     masm.computeEffectiveAddress(address, output);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAsmJSLoadGlobalVar(LAsmJSLoadGlobalVar *ins)
 {
     const MAsmJSLoadGlobalVar *mir = ins->mir();
     unsigned addr = mir->globalDataOffset();
     if (mir->type() == MIRType_Int32)
         masm.load32(Address(GlobalReg, addr), ToRegister(ins->output()));
     else if (mir->type() == MIRType_Float32)
         masm.loadFloat32(Address(GlobalReg, addr), ToFloatRegister(ins->output()));
     else
         masm.loadDouble(Address(GlobalReg, addr), ToFloatRegister(ins->output()));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAsmJSStoreGlobalVar(LAsmJSStoreGlobalVar *ins)
 {
     const MAsmJSStoreGlobalVar *mir = ins->mir();
     MIRType type = mir->value()->type();
     MOZ_ASSERT(IsNumberType(type));
     unsigned addr = mir->globalDataOffset();
     if (mir->value()->type() == MIRType_Int32)
         masm.store32(ToRegister(ins->value()), Address(GlobalReg, addr));
     else if (mir->value()->type() == MIRType_Float32)
         masm.storeFloat32(ToFloatRegister(ins->value()), Address(GlobalReg, addr));
     else
         masm.storeDouble(ToFloatRegister(ins->value()), Address(GlobalReg, addr));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAsmJSLoadFuncPtr(LAsmJSLoadFuncPtr *ins)
 {
     const MAsmJSLoadFuncPtr *mir = ins->mir();
     Register index = ToRegister(ins->index());
     Register tmp = ToRegister(ins->temp());
     Register out = ToRegister(ins->output());
     unsigned addr = mir->globalDataOffset();
     BaseIndex source(GlobalReg, index, TimesFour, addr);
     masm.load32(source, out);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitAsmJSLoadFFIFunc(LAsmJSLoadFFIFunc *ins)
 {
     const MAsmJSLoadFFIFunc *mir = ins->mir();
     masm.loadPtr(Address(GlobalReg, mir->globalDataOffset()), ToRegister(ins->output()));
     return true;
 }
 bool
 CodeGeneratorMIPS::visitNegI(LNegI *ins)
 {
     Register input = ToRegister(ins->input());
     Register output = ToRegister(ins->output());
     masm.ma_negu(output, input);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitNegD(LNegD *ins)
 {
     FloatRegister input = ToFloatRegister(ins->input());
     FloatRegister output = ToFloatRegister(ins->output());
     masm.as_negd(output, input);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitNegF(LNegF *ins)
 {
     FloatRegister input = ToFloatRegister(ins->input());
     FloatRegister output = ToFloatRegister(ins->output());
     masm.as_negs(output, input);
     return true;
 }
 bool
 CodeGeneratorMIPS::visitForkJoinGetSlice(LForkJoinGetSlice *ins)
 {
     MOZ_ASSUME_UNREACHABLE("NYI");
 }
 JitCode *
 JitRuntime::generateForkJoinGetSliceStub(JSContext *cx)
 {
     MOZ_ASSUME_UNREACHABLE("NYI");
 }

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js/src/jit/mips/CodeGenerator-mips.cpp@b8a032363ba2 (annotated)

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