本文整理汇总了C++中TargetRegisterInfo::getConstrainedRegClassForOperand方法的典型用法代码示例。如果您正苦于以下问题：C++ TargetRegisterInfo::getConstrainedRegClassForOperand方法的具体用法？C++ TargetRegisterInfo::getConstrainedRegClassForOperand怎么用？C++ TargetRegisterInfo::getConstrainedRegClassForOperand使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类TargetRegisterInfo的用法示例。
在下文中一共展示了TargetRegisterInfo::getConstrainedRegClassForOperand方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: constrainOperandRegClass
unsigned llvm::constrainOperandRegClass(
const MachineFunction &MF, const TargetRegisterInfo &TRI,
MachineRegisterInfo &MRI, const TargetInstrInfo &TII,
const RegisterBankInfo &RBI, MachineInstr &InsertPt, const MCInstrDesc &II,
const MachineOperand &RegMO, unsigned OpIdx) {
unsigned Reg = RegMO.getReg();
// Assume physical registers are properly constrained.
assert(TargetRegisterInfo::isVirtualRegister(Reg) &&
"PhysReg not implemented");
const TargetRegisterClass *RegClass = TII.getRegClass(II, OpIdx, &TRI, MF);
// Some of the target independent instructions, like COPY, may not impose any
// register class constraints on some of their operands: If it's a use, we can
// skip constraining as the instruction defining the register would constrain
// it.
// We can't constrain unallocatable register classes, because we can't create
// virtual registers for these classes, so we need to let targets handled this
// case.
if (RegClass && !RegClass->isAllocatable())
RegClass = TRI.getConstrainedRegClassForOperand(RegMO, MRI);
if (!RegClass) {
assert((!isTargetSpecificOpcode(II.getOpcode()) || RegMO.isUse()) &&
"Register class constraint is required unless either the "
"instruction is target independent or the operand is a use");
// FIXME: Just bailing out like this here could be not enough, unless we
// expect the users of this function to do the right thing for PHIs and
// COPY:
// v1 = COPY v0
// v2 = COPY v1
// v1 here may end up not being constrained at all. Please notice that to
// reproduce the issue we likely need a destination pattern of a selection
// rule producing such extra copies, not just an input GMIR with them as
// every existing target using selectImpl handles copies before calling it
// and they never reach this function.
return Reg;
}
return constrainRegToClass(MRI, TII, RBI, InsertPt, Reg, *RegClass);
}