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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "jit/BaselineIC.h"
#include "jit/SharedICHelpers.h"
#include "jit/MacroAssembler-inl.h"
using namespace js;
using namespace js::jit;
namespace js {
namespace jit {
// ICBinaryArith_Int32
bool
ICBinaryArith_Int32::Compiler::generateStubCode(MacroAssembler& masm)
{
// Guard that R0 is an integer and R1 is an integer.
Label failure;
masm.branchTestInt32(Assembler::NotEqual, R0, &failure);
masm.branchTestInt32(Assembler::NotEqual, R1, &failure);
// The scratch register is only used in the case of JSOP_URSH.
mozilla::Maybe<ScratchRegisterScope> scratch;
Label revertRegister, maybeNegZero;
switch(op_) {
case JSOP_ADD:
masm.unboxInt32(R0, ExtractTemp0);
// Just jump to failure on overflow. R0 and R1 are preserved, so we can just jump to
// the next stub.
masm.addl(R1.valueReg(), ExtractTemp0);
masm.j(Assembler::Overflow, &failure);
// Box the result
masm.boxValue(JSVAL_TYPE_INT32, ExtractTemp0, R0.valueReg());
break;
case JSOP_SUB:
masm.unboxInt32(R0, ExtractTemp0);
masm.subl(R1.valueReg(), ExtractTemp0);
masm.j(Assembler::Overflow, &failure);
masm.boxValue(JSVAL_TYPE_INT32, ExtractTemp0, R0.valueReg());
break;
case JSOP_MUL:
masm.unboxInt32(R0, ExtractTemp0);
masm.imull(R1.valueReg(), ExtractTemp0);
masm.j(Assembler::Overflow, &failure);
masm.branchTest32(Assembler::Zero, ExtractTemp0, ExtractTemp0, &maybeNegZero);
masm.boxValue(JSVAL_TYPE_INT32, ExtractTemp0, R0.valueReg());
break;
case JSOP_DIV:
{
MOZ_ASSERT(R2.scratchReg() == rax);
MOZ_ASSERT(R0.valueReg() != rdx);
MOZ_ASSERT(R1.valueReg() != rdx);
masm.unboxInt32(R0, eax);
masm.unboxInt32(R1, ExtractTemp0);
// Prevent division by 0.
masm.branchTest32(Assembler::Zero, ExtractTemp0, ExtractTemp0, &failure);
// Prevent negative 0 and -2147483648 / -1.
masm.branch32(Assembler::Equal, eax, Imm32(INT32_MIN), &failure);
Label notZero;
masm.branch32(Assembler::NotEqual, eax, Imm32(0), ¬Zero);
masm.branchTest32(Assembler::Signed, ExtractTemp0, ExtractTemp0, &failure);
masm.bind(¬Zero);
// Sign extend eax into edx to make (edx:eax), since idiv is 64-bit.
masm.cdq();
masm.idiv(ExtractTemp0);
// A remainder implies a double result.
masm.branchTest32(Assembler::NonZero, edx, edx, &failure);
masm.boxValue(JSVAL_TYPE_INT32, eax, R0.valueReg());
break;
}
case JSOP_MOD:
{
MOZ_ASSERT(R2.scratchReg() == rax);
MOZ_ASSERT(R0.valueReg() != rdx);
MOZ_ASSERT(R1.valueReg() != rdx);
masm.unboxInt32(R0, eax);
masm.unboxInt32(R1, ExtractTemp0);
// x % 0 always results in NaN.
masm.branchTest32(Assembler::Zero, ExtractTemp0, ExtractTemp0, &failure);
// Prevent negative 0 and -2147483648 % -1.
masm.branchTest32(Assembler::Zero, eax, Imm32(0x7fffffff), &failure);
// Sign extend eax into edx to make (edx:eax), since idiv is 64-bit.
masm.cdq();
masm.idiv(ExtractTemp0);
// Fail when we would need a negative remainder.
Label done;
masm.branchTest32(Assembler::NonZero, edx, edx, &done);
masm.orl(ExtractTemp0, eax);
masm.branchTest32(Assembler::Signed, eax, eax, &failure);
masm.bind(&done);
masm.boxValue(JSVAL_TYPE_INT32, edx, R0.valueReg());
break;
}
case JSOP_BITOR:
// We can overide R0, because the instruction is unfailable.
// Because the tag bits are the same, we don't need to retag.
masm.orq(R1.valueReg(), R0.valueReg());
break;
case JSOP_BITXOR:
masm.xorl(R1.valueReg(), R0.valueReg());
masm.tagValue(JSVAL_TYPE_INT32, R0.valueReg(), R0);
break;
case JSOP_BITAND:
masm.andq(R1.valueReg(), R0.valueReg());
break;
case JSOP_LSH:
masm.unboxInt32(R0, ExtractTemp0);
masm.unboxInt32(R1, ecx); // Unboxing R1 to ecx, clobbers R0.
masm.shll_cl(ExtractTemp0);
masm.boxValue(JSVAL_TYPE_INT32, ExtractTemp0, R0.valueReg());
break;
case JSOP_RSH:
masm.unboxInt32(R0, ExtractTemp0);
masm.unboxInt32(R1, ecx);
masm.sarl_cl(ExtractTemp0);
masm.boxValue(JSVAL_TYPE_INT32, ExtractTemp0, R0.valueReg());
break;
case JSOP_URSH:
if (!allowDouble_) {
scratch.emplace(masm);
masm.movq(R0.valueReg(), *scratch);
}
masm.unboxInt32(R0, ExtractTemp0);
masm.unboxInt32(R1, ecx); // This clobbers R0
masm.shrl_cl(ExtractTemp0);
masm.test32(ExtractTemp0, ExtractTemp0);
if (allowDouble_) {
Label toUint;
masm.j(Assembler::Signed, &toUint);
// Box and return.
masm.boxValue(JSVAL_TYPE_INT32, ExtractTemp0, R0.valueReg());
EmitReturnFromIC(masm);
masm.bind(&toUint);
ScratchDoubleScope scratchDouble(masm);
masm.convertUInt32ToDouble(ExtractTemp0, scratchDouble);
masm.boxDouble(scratchDouble, R0);
} else {
masm.j(Assembler::Signed, &revertRegister);
masm.boxValue(JSVAL_TYPE_INT32, ExtractTemp0, R0.valueReg());
}
break;
default:
MOZ_CRASH("Unhandled op in BinaryArith_Int32");
}
// Return from stub.
EmitReturnFromIC(masm);
if (op_ == JSOP_MUL) {
masm.bind(&maybeNegZero);
// Result is -0 if exactly one of lhs or rhs is negative.
{
ScratchRegisterScope scratch(masm);
masm.movl(R0.valueReg(), scratch);
masm.orl(R1.valueReg(), scratch);
masm.j(Assembler::Signed, &failure);
}
// Result is +0.
masm.moveValue(Int32Value(0), R0);
EmitReturnFromIC(masm);
}
// Revert the content of R0 in the fallible >>> case.
if (op_ == JSOP_URSH && !allowDouble_) {
// Scope continuation from JSOP_URSH case above.
masm.bind(&revertRegister);
// Restore tag and payload.
masm.movq(*scratch, R0.valueReg());
// Fall through to failure.
}
// Failure case - jump to next stub
masm.bind(&failure);
EmitStubGuardFailure(masm);
return true;
}
bool
ICUnaryArith_Int32::Compiler::generateStubCode(MacroAssembler& masm)
{
Label failure;
masm.branchTestInt32(Assembler::NotEqual, R0, &failure);
switch (op) {
case JSOP_BITNOT:
masm.notl(R0.valueReg());
break;
case JSOP_NEG:
// Guard against 0 and MIN_INT, both result in a double.
masm.branchTest32(Assembler::Zero, R0.valueReg(), Imm32(0x7fffffff), &failure);
masm.negl(R0.valueReg());
break;
default:
MOZ_CRASH("Unexpected op");
}
masm.tagValue(JSVAL_TYPE_INT32, R0.valueReg(), R0);
EmitReturnFromIC(masm);
masm.bind(&failure);
EmitStubGuardFailure(masm);
return true;
}
} // namespace jit
} // namespace js
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