/* -*- 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