188 lines · cpp
1//=== lib/CodeGen/GlobalISel/AArch64O0PreLegalizerCombiner.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 pass does combining of machine instructions at the generic MI level,10// before the legalizer.11//12//===----------------------------------------------------------------------===//13 14#include "AArch64GlobalISelUtils.h"15#include "AArch64TargetMachine.h"16#include "llvm/CodeGen/GlobalISel/Combiner.h"17#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"18#include "llvm/CodeGen/GlobalISel/CombinerInfo.h"19#include "llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h"20#include "llvm/CodeGen/GlobalISel/GISelValueTracking.h"21#include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"22#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"23#include "llvm/CodeGen/MachineDominators.h"24#include "llvm/CodeGen/MachineFunction.h"25#include "llvm/CodeGen/MachineFunctionPass.h"26#include "llvm/CodeGen/TargetPassConfig.h"27#include "llvm/IR/Instructions.h"28 29#define GET_GICOMBINER_DEPS30#include "AArch64GenO0PreLegalizeGICombiner.inc"31#undef GET_GICOMBINER_DEPS32 33#define DEBUG_TYPE "aarch64-O0-prelegalizer-combiner"34 35using namespace llvm;36using namespace MIPatternMatch;37namespace {38#define GET_GICOMBINER_TYPES39#include "AArch64GenO0PreLegalizeGICombiner.inc"40#undef GET_GICOMBINER_TYPES41 42class AArch64O0PreLegalizerCombinerImpl : public Combiner {43protected:44 const CombinerHelper Helper;45 const AArch64O0PreLegalizerCombinerImplRuleConfig &RuleConfig;46 const AArch64Subtarget &STI;47 48public:49 AArch64O0PreLegalizerCombinerImpl(50 MachineFunction &MF, CombinerInfo &CInfo, const TargetPassConfig *TPC,51 GISelValueTracking &VT, GISelCSEInfo *CSEInfo,52 const AArch64O0PreLegalizerCombinerImplRuleConfig &RuleConfig,53 const AArch64Subtarget &STI);54 55 static const char *getName() { return "AArch64O0PreLegalizerCombiner"; }56 57 bool tryCombineAll(MachineInstr &I) const override;58 59 bool tryCombineAllImpl(MachineInstr &I) const;60 61private:62#define GET_GICOMBINER_CLASS_MEMBERS63#include "AArch64GenO0PreLegalizeGICombiner.inc"64#undef GET_GICOMBINER_CLASS_MEMBERS65};66 67#define GET_GICOMBINER_IMPL68#include "AArch64GenO0PreLegalizeGICombiner.inc"69#undef GET_GICOMBINER_IMPL70 71AArch64O0PreLegalizerCombinerImpl::AArch64O0PreLegalizerCombinerImpl(72 MachineFunction &MF, CombinerInfo &CInfo, const TargetPassConfig *TPC,73 GISelValueTracking &VT, GISelCSEInfo *CSEInfo,74 const AArch64O0PreLegalizerCombinerImplRuleConfig &RuleConfig,75 const AArch64Subtarget &STI)76 : Combiner(MF, CInfo, TPC, &VT, CSEInfo),77 Helper(Observer, B, /*IsPreLegalize*/ true, &VT), RuleConfig(RuleConfig),78 STI(STI),79#define GET_GICOMBINER_CONSTRUCTOR_INITS80#include "AArch64GenO0PreLegalizeGICombiner.inc"81#undef GET_GICOMBINER_CONSTRUCTOR_INITS82{83}84 85bool AArch64O0PreLegalizerCombinerImpl::tryCombineAll(MachineInstr &MI) const {86 if (tryCombineAllImpl(MI))87 return true;88 89 unsigned Opc = MI.getOpcode();90 switch (Opc) {91 case TargetOpcode::G_SHUFFLE_VECTOR:92 return Helper.tryCombineShuffleVector(MI);93 case TargetOpcode::G_MEMCPY_INLINE:94 return Helper.tryEmitMemcpyInline(MI);95 case TargetOpcode::G_MEMCPY:96 case TargetOpcode::G_MEMMOVE:97 case TargetOpcode::G_MEMSET: {98 // At -O0 set a maxlen of 32 to inline;99 unsigned MaxLen = 32;100 // Try to inline memcpy type calls if optimizations are enabled.101 if (Helper.tryCombineMemCpyFamily(MI, MaxLen))102 return true;103 if (Opc == TargetOpcode::G_MEMSET)104 return llvm::AArch64GISelUtils::tryEmitBZero(MI, B, CInfo.EnableMinSize);105 return false;106 }107 }108 109 return false;110}111 112// Pass boilerplate113// ================114 115class AArch64O0PreLegalizerCombiner : public MachineFunctionPass {116public:117 static char ID;118 119 AArch64O0PreLegalizerCombiner();120 121 StringRef getPassName() const override {122 return "AArch64O0PreLegalizerCombiner";123 }124 125 bool runOnMachineFunction(MachineFunction &MF) override;126 127 void getAnalysisUsage(AnalysisUsage &AU) const override;128 129private:130 AArch64O0PreLegalizerCombinerImplRuleConfig RuleConfig;131};132} // end anonymous namespace133 134void AArch64O0PreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {135 AU.addRequired<TargetPassConfig>();136 AU.setPreservesCFG();137 getSelectionDAGFallbackAnalysisUsage(AU);138 AU.addRequired<GISelValueTrackingAnalysisLegacy>();139 AU.addPreserved<GISelValueTrackingAnalysisLegacy>();140 MachineFunctionPass::getAnalysisUsage(AU);141}142 143AArch64O0PreLegalizerCombiner::AArch64O0PreLegalizerCombiner()144 : MachineFunctionPass(ID) {145 if (!RuleConfig.parseCommandLineOption())146 report_fatal_error("Invalid rule identifier");147}148 149bool AArch64O0PreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) {150 if (MF.getProperties().hasFailedISel())151 return false;152 auto &TPC = getAnalysis<TargetPassConfig>();153 154 const Function &F = MF.getFunction();155 GISelValueTracking *VT =156 &getAnalysis<GISelValueTrackingAnalysisLegacy>().get(MF);157 158 const AArch64Subtarget &ST = MF.getSubtarget<AArch64Subtarget>();159 160 CombinerInfo CInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false,161 /*LegalizerInfo*/ nullptr, /*EnableOpt*/ false,162 F.hasOptSize(), F.hasMinSize());163 // Disable fixed-point iteration in the Combiner. This improves compile-time164 // at the cost of possibly missing optimizations. See PR#94291 for details.165 CInfo.MaxIterations = 1;166 167 AArch64O0PreLegalizerCombinerImpl Impl(MF, CInfo, &TPC, *VT,168 /*CSEInfo*/ nullptr, RuleConfig, ST);169 return Impl.combineMachineInstrs();170}171 172char AArch64O0PreLegalizerCombiner::ID = 0;173INITIALIZE_PASS_BEGIN(AArch64O0PreLegalizerCombiner, DEBUG_TYPE,174 "Combine AArch64 machine instrs before legalization",175 false, false)176INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)177INITIALIZE_PASS_DEPENDENCY(GISelValueTrackingAnalysisLegacy)178INITIALIZE_PASS_DEPENDENCY(GISelCSEAnalysisWrapperPass)179INITIALIZE_PASS_END(AArch64O0PreLegalizerCombiner, DEBUG_TYPE,180 "Combine AArch64 machine instrs before legalization", false,181 false)182 183namespace llvm {184FunctionPass *createAArch64O0PreLegalizerCombiner() {185 return new AArch64O0PreLegalizerCombiner();186}187} // end namespace llvm188