Commit c67e1a98 authored by Matt Arsenault's avatar Matt Arsenault
Browse files

GlobalISel: Directly expose getDefSrcRegIgnoringCopies utility 

It's useful to get both the instruction and register at the same time.
parent 8741a76f

llvm/include/llvm/CodeGen/GlobalISel/Utils.h

+12 −0
Original line number Diff line number Diff line
@@ -151,6 +151,18 @@ const ConstantFP* getConstantFPVRegVal(Register VReg, 
MachineInstr *getOpcodeDef(unsigned Opcode, Register Reg,

                           const MachineRegisterInfo &MRI);



/// Simple struct used to hold a Register value and the instruction which

/// defines it.

struct DefinitionAndSourceRegister {

  MachineInstr *MI;

  Register Reg;

};



/// Find the def instruction for \p Reg, and underlying value Register folding

/// away any copies.

Optional<DefinitionAndSourceRegister>

getDefSrcRegIgnoringCopies(Register Reg, const MachineRegisterInfo &MRI);



/// Find the def instruction for \p Reg, folding away any trivial copies. May

/// return nullptr if \p Reg is not a generic virtual register.

MachineInstr *getDefIgnoringCopies(Register Reg,

llvm/lib/CodeGen/GlobalISel/Utils.cpp

+2 −9
Original line number Diff line number Diff line
@@ -351,15 +351,8 @@ llvm::getConstantFPVRegVal(Register VReg, const MachineRegisterInfo &MRI) { 
  return MI->getOperand(1).getFPImm();

}



namespace {

struct DefinitionAndSourceRegister {

  MachineInstr *MI;

  Register Reg;

};

} // namespace



static Optional<DefinitionAndSourceRegister>

getDefSrcRegIgnoringCopies(Register Reg, const MachineRegisterInfo &MRI) {

Optional<DefinitionAndSourceRegister>

llvm::getDefSrcRegIgnoringCopies(Register Reg, const MachineRegisterInfo &MRI) {

  Register DefSrcReg = Reg;

  auto *DefMI = MRI.getVRegDef(Reg);

  auto DstTy = MRI.getType(DefMI->getOperand(0).getReg());