116 lines
3.8 KiB
C++
116 lines
3.8 KiB
C++
//===- CombinerHelperCasts.cpp---------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements CombinerHelper for G_ANYEXT, G_SEXT, G_TRUNC, and
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// G_ZEXT
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
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#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
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#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
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#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
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#include "llvm/CodeGen/GlobalISel/Utils.h"
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#include "llvm/CodeGen/LowLevelTypeUtils.h"
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#include "llvm/CodeGen/MachineOperand.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/CodeGen/TargetOpcodes.h"
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#include "llvm/Support/Casting.h"
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#define DEBUG_TYPE "gi-combiner"
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using namespace llvm;
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bool CombinerHelper::matchSextOfTrunc(const MachineOperand &MO,
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BuildFnTy &MatchInfo) {
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GSext *Sext = cast<GSext>(getDefIgnoringCopies(MO.getReg(), MRI));
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GTrunc *Trunc = cast<GTrunc>(getDefIgnoringCopies(Sext->getSrcReg(), MRI));
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Register Dst = Sext->getReg(0);
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Register Src = Trunc->getSrcReg();
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LLT DstTy = MRI.getType(Dst);
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LLT SrcTy = MRI.getType(Src);
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if (DstTy == SrcTy) {
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MatchInfo = [=](MachineIRBuilder &B) { B.buildCopy(Dst, Src); };
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return true;
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}
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if (DstTy.getScalarSizeInBits() < SrcTy.getScalarSizeInBits() &&
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isLegalOrBeforeLegalizer({TargetOpcode::G_TRUNC, {DstTy, SrcTy}})) {
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MatchInfo = [=](MachineIRBuilder &B) {
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B.buildTrunc(Dst, Src, MachineInstr::MIFlag::NoSWrap);
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};
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return true;
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}
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if (DstTy.getScalarSizeInBits() > SrcTy.getScalarSizeInBits() &&
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isLegalOrBeforeLegalizer({TargetOpcode::G_SEXT, {DstTy, SrcTy}})) {
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MatchInfo = [=](MachineIRBuilder &B) { B.buildSExt(Dst, Src); };
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return true;
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}
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return false;
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}
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bool CombinerHelper::matchZextOfTrunc(const MachineOperand &MO,
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BuildFnTy &MatchInfo) {
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GZext *Zext = cast<GZext>(getDefIgnoringCopies(MO.getReg(), MRI));
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GTrunc *Trunc = cast<GTrunc>(getDefIgnoringCopies(Zext->getSrcReg(), MRI));
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Register Dst = Zext->getReg(0);
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Register Src = Trunc->getSrcReg();
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LLT DstTy = MRI.getType(Dst);
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LLT SrcTy = MRI.getType(Src);
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if (DstTy == SrcTy) {
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MatchInfo = [=](MachineIRBuilder &B) { B.buildCopy(Dst, Src); };
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return true;
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}
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if (DstTy.getScalarSizeInBits() < SrcTy.getScalarSizeInBits() &&
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isLegalOrBeforeLegalizer({TargetOpcode::G_TRUNC, {DstTy, SrcTy}})) {
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MatchInfo = [=](MachineIRBuilder &B) {
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B.buildTrunc(Dst, Src, MachineInstr::MIFlag::NoUWrap);
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};
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return true;
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}
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if (DstTy.getScalarSizeInBits() > SrcTy.getScalarSizeInBits() &&
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isLegalOrBeforeLegalizer({TargetOpcode::G_ZEXT, {DstTy, SrcTy}})) {
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MatchInfo = [=](MachineIRBuilder &B) {
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B.buildZExt(Dst, Src, MachineInstr::MIFlag::NonNeg);
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};
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return true;
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}
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return false;
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}
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bool CombinerHelper::matchNonNegZext(const MachineOperand &MO,
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BuildFnTy &MatchInfo) {
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GZext *Zext = cast<GZext>(MRI.getVRegDef(MO.getReg()));
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Register Dst = Zext->getReg(0);
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Register Src = Zext->getSrcReg();
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LLT DstTy = MRI.getType(Dst);
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LLT SrcTy = MRI.getType(Src);
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const auto &TLI = getTargetLowering();
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// Convert zext nneg to sext if sext is the preferred form for the target.
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if (isLegalOrBeforeLegalizer({TargetOpcode::G_SEXT, {DstTy, SrcTy}}) &&
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TLI.isSExtCheaperThanZExt(getMVTForLLT(SrcTy), getMVTForLLT(DstTy))) {
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MatchInfo = [=](MachineIRBuilder &B) { B.buildSExt(Dst, Src); };
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return true;
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}
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return false;
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}
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