void JIT::emit_op_pre_dec(Instruction* currentInstruction)
{
unsigned srcDst = currentInstruction[1].u.operand;
emitGetVirtualRegister(srcDst, regT0);
emitJumpSlowCaseIfNotImmediateInteger(regT0);
addSlowCase(branchSub32(Zero, Imm32(1), regT0));
emitFastArithIntToImmNoCheck(regT0, regT0);
emitPutVirtualRegister(srcDst);
}
void JIT::compileBinaryArithOp(OpcodeID opcodeID, unsigned, unsigned op1, unsigned op2, OperandTypes)
{
emitGetVirtualRegisters(op1, regT0, op2, regT1);
emitJumpSlowCaseIfNotImmediateInteger(regT0);
emitJumpSlowCaseIfNotImmediateInteger(regT1);
if (opcodeID == op_add)
addSlowCase(branchAdd32(Overflow, regT1, regT0));
else if (opcodeID == op_sub)
addSlowCase(branchSub32(Overflow, regT1, regT0));
else {
ASSERT(opcodeID == op_mul);
addSlowCase(branchMul32(Overflow, regT1, regT0));
addSlowCase(branchTest32(Zero, regT0));
}
emitFastArithIntToImmNoCheck(regT0, regT0);
}
void JIT::compileLoadVarargs(Instruction* instruction)
{
int thisValue = instruction[3].u.operand;
int arguments = instruction[4].u.operand;
int firstFreeRegister = instruction[5].u.operand;
JumpList slowCase;
JumpList end;
bool canOptimize = m_codeBlock->usesArguments()
&& VirtualRegister(arguments) == m_codeBlock->argumentsRegister()
&& !m_codeBlock->symbolTable()->slowArguments();
if (canOptimize) {
emitLoadTag(arguments, regT1);
slowCase.append(branch32(NotEqual, regT1, TrustedImm32(JSValue::EmptyValueTag)));
load32(payloadFor(JSStack::ArgumentCount), regT2);
slowCase.append(branch32(Above, regT2, TrustedImm32(Arguments::MaxArguments + 1)));
// regT2: argumentCountIncludingThis
move(regT2, regT3);
neg32(regT3);
add32(TrustedImm32(firstFreeRegister - JSStack::CallFrameHeaderSize), regT3);
lshift32(TrustedImm32(3), regT3);
addPtr(callFrameRegister, regT3);
// regT3: newCallFrame
slowCase.append(branchPtr(Above, AbsoluteAddress(m_vm->interpreter->stack().addressOfEnd()), regT3));
// Initialize ArgumentCount.
store32(regT2, payloadFor(JSStack::ArgumentCount, regT3));
// Initialize 'this'.
emitLoad(thisValue, regT1, regT0);
store32(regT0, Address(regT3, OBJECT_OFFSETOF(JSValue, u.asBits.payload) + (CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)))));
store32(regT1, Address(regT3, OBJECT_OFFSETOF(JSValue, u.asBits.tag) + (CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)))));
// Copy arguments.
end.append(branchSub32(Zero, TrustedImm32(1), regT2));
// regT2: argumentCount;
Label copyLoop = label();
load32(BaseIndex(callFrameRegister, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.payload) +(CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)))), regT0);
load32(BaseIndex(callFrameRegister, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.tag) +(CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)))), regT1);
store32(regT0, BaseIndex(regT3, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.payload) +(CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)))));
store32(regT1, BaseIndex(regT3, regT2, TimesEight, OBJECT_OFFSETOF(JSValue, u.asBits.tag) +(CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)))));
branchSub32(NonZero, TrustedImm32(1), regT2).linkTo(copyLoop, this);
end.append(jump());
}
if (canOptimize)
slowCase.link(this);
emitLoad(thisValue, regT1, regT0);
emitLoad(arguments, regT3, regT2);
callOperation(operationLoadVarargs, regT1, regT0, regT3, regT2, firstFreeRegister);
move(returnValueRegister, regT3);
if (canOptimize)
end.link(this);
}