forked from OSchip/llvm-project
42 lines
1.3 KiB
C++
42 lines
1.3 KiB
C++
//== ---lib/CodeGen/GlobalISel/GICombinerHelper.cpp --------------------- == //
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
|
|
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
|
|
#include "llvm/CodeGen/GlobalISel/Utils.h"
|
|
#include "llvm/CodeGen/MachineInstr.h"
|
|
#include "llvm/CodeGen/MachineRegisterInfo.h"
|
|
|
|
#define DEBUG_TYPE "gi-combine"
|
|
|
|
using namespace llvm;
|
|
|
|
CombinerHelper::CombinerHelper(MachineIRBuilder &B) :
|
|
Builder(B), MRI(Builder.getMF().getRegInfo()) {}
|
|
|
|
bool CombinerHelper::tryCombineCopy(MachineInstr &MI) {
|
|
if (MI.getOpcode() != TargetOpcode::COPY)
|
|
return false;
|
|
unsigned DstReg = MI.getOperand(0).getReg();
|
|
unsigned SrcReg = MI.getOperand(1).getReg();
|
|
LLT DstTy = MRI.getType(DstReg);
|
|
LLT SrcTy = MRI.getType(SrcReg);
|
|
// Simple Copy Propagation.
|
|
// a(sx) = COPY b(sx) -> Replace all uses of a with b.
|
|
if (DstTy.isValid() && SrcTy.isValid() && DstTy == SrcTy) {
|
|
MI.eraseFromParent();
|
|
MRI.replaceRegWith(DstReg, SrcReg);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool CombinerHelper::tryCombine(MachineInstr &MI) {
|
|
return tryCombineCopy(MI);
|
|
}
|