| 12
 3
 4
 5
 6
 7
 8
 9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 
 | //===- CombinerHelperArtifacts.cpp-----------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements CombinerHelper for legalization artifacts.
//
//===----------------------------------------------------------------------===//
//
// G_MERGE_VALUES
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/LowLevelTypeUtils.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/Support/Casting.h"
#define DEBUG_TYPE "gi-combiner"
using namespace llvm;
bool CombinerHelper::matchMergeXAndUndef(const MachineInstr &MI,
                                         BuildFnTy &MatchInfo) const {
  const GMerge *Merge = cast<GMerge>(&MI);
  Register Dst = Merge->getReg(0);
  LLT DstTy = MRI.getType(Dst);
  LLT SrcTy = MRI.getType(Merge->getSourceReg(0));
  // Otherwise, we would miscompile.
  assert(Merge->getNumSources() == 2 && "Unexpected number of operands");
  //
  //   %bits_8_15:_(s8) = G_IMPLICIT_DEF
  //   %0:_(s16) = G_MERGE_VALUES %bits_0_7:(s8), %bits_8_15:(s8)
  //
  // ->
  //
  //   %0:_(s16) = G_ANYEXT %bits_0_7:(s8)
  //
  if (!isLegalOrBeforeLegalizer({TargetOpcode::G_ANYEXT, {DstTy, SrcTy}}))
    return false;
  MatchInfo = [=](MachineIRBuilder &B) {
    B.buildAnyExt(Dst, Merge->getSourceReg(0));
  };
  return true;
}
bool CombinerHelper::matchMergeXAndZero(const MachineInstr &MI,
                                        BuildFnTy &MatchInfo) const {
  const GMerge *Merge = cast<GMerge>(&MI);
  Register Dst = Merge->getReg(0);
  LLT DstTy = MRI.getType(Dst);
  LLT SrcTy = MRI.getType(Merge->getSourceReg(0));
  // No multi-use check. It is a constant.
  //
  //   %bits_8_15:_(s8) = G_CONSTANT i8 0
  //   %0:_(s16) = G_MERGE_VALUES %bits_0_7:(s8), %bits_8_15:(s8)
  //
  // ->
  //
  //   %0:_(s16) = G_ZEXT %bits_0_7:(s8)
  //
  if (!isLegalOrBeforeLegalizer({TargetOpcode::G_ZEXT, {DstTy, SrcTy}}))
    return false;
  MatchInfo = [=](MachineIRBuilder &B) {
    B.buildZExt(Dst, Merge->getSourceReg(0));
  };
  return true;
}
 |