86 lines · cpp
1//===- CombinerHelperArtifacts.cpp-----------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements CombinerHelper for legalization artifacts.10//11//===----------------------------------------------------------------------===//12//13// G_MERGE_VALUES14//15//===----------------------------------------------------------------------===//16#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"17#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"18#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"19#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"20#include "llvm/CodeGen/GlobalISel/Utils.h"21#include "llvm/CodeGen/MachineOperand.h"22#include "llvm/CodeGen/MachineRegisterInfo.h"23#include "llvm/CodeGen/TargetOpcodes.h"24#include "llvm/Support/Casting.h"25 26#define DEBUG_TYPE "gi-combiner"27 28using namespace llvm;29 30bool CombinerHelper::matchMergeXAndUndef(const MachineInstr &MI,31 BuildFnTy &MatchInfo) const {32 const GMerge *Merge = cast<GMerge>(&MI);33 34 Register Dst = Merge->getReg(0);35 LLT DstTy = MRI.getType(Dst);36 LLT SrcTy = MRI.getType(Merge->getSourceReg(0));37 38 // Otherwise, we would miscompile.39 assert(Merge->getNumSources() == 2 && "Unexpected number of operands");40 41 //42 // %bits_8_15:_(s8) = G_IMPLICIT_DEF43 // %0:_(s16) = G_MERGE_VALUES %bits_0_7:(s8), %bits_8_15:(s8)44 //45 // ->46 //47 // %0:_(s16) = G_ANYEXT %bits_0_7:(s8)48 //49 50 if (!isLegalOrBeforeLegalizer({TargetOpcode::G_ANYEXT, {DstTy, SrcTy}}))51 return false;52 53 MatchInfo = [=](MachineIRBuilder &B) {54 B.buildAnyExt(Dst, Merge->getSourceReg(0));55 };56 return true;57}58 59bool CombinerHelper::matchMergeXAndZero(const MachineInstr &MI,60 BuildFnTy &MatchInfo) const {61 const GMerge *Merge = cast<GMerge>(&MI);62 63 Register Dst = Merge->getReg(0);64 LLT DstTy = MRI.getType(Dst);65 LLT SrcTy = MRI.getType(Merge->getSourceReg(0));66 67 // No multi-use check. It is a constant.68 69 //70 // %bits_8_15:_(s8) = G_CONSTANT i8 071 // %0:_(s16) = G_MERGE_VALUES %bits_0_7:(s8), %bits_8_15:(s8)72 //73 // ->74 //75 // %0:_(s16) = G_ZEXT %bits_0_7:(s8)76 //77 78 if (!isLegalOrBeforeLegalizer({TargetOpcode::G_ZEXT, {DstTy, SrcTy}}))79 return false;80 81 MatchInfo = [=](MachineIRBuilder &B) {82 B.buildZExt(Dst, Merge->getSourceReg(0));83 };84 return true;85}86