MipsPostLegalizerCombiner.cpp

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//=== lib/CodeGen/GlobalISel/MipsPostLegalizerCombiner.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 pass does combining of machine instructions at the generic MI level,
// after the legalizer.
//
//===----------------------------------------------------------------------===//
 
#include "MCTargetDesc/MipsMCTargetDesc.h"
#include "Mips.h"
#include "MipsLegalizerInfo.h"
#include "MipsSubtarget.h"
#include "llvm/CodeGen/GlobalISel/Combiner.h"
#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
#include "llvm/CodeGen/GlobalISel/CombinerInfo.h"
#include "llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h"
#include "llvm/CodeGen/GlobalISel/GISelValueTracking.h"
#include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionAnalysisManager.h"
#include "llvm/CodeGen/MachinePassManager.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/IR/Analysis.h"
#include "llvm/Target/TargetMachine.h"
 
#define GET_GICOMBINER_DEPS
#include "MipsGenPostLegalizeGICombiner.inc"
#undef GET_GICOMBINER_DEPS
 
#define DEBUG_TYPE "mips-postlegalizer-combiner"
 
using namespace llvm;
using namespace MIPatternMatch;
 
namespace {
#define GET_GICOMBINER_TYPES
#include "MipsGenPostLegalizeGICombiner.inc"
#undef GET_GICOMBINER_TYPES
 
class MipsPostLegalizerCombinerImpl : public Combiner {
protected:
  const MipsPostLegalizerCombinerImplRuleConfig &RuleConfig;
  const MipsSubtarget &STI;
  const CombinerHelper Helper;
 
public:
  MipsPostLegalizerCombinerImpl(
      MachineFunction &MF, CombinerInfo &CInfo, GISelValueTracking &VT,
      GISelCSEInfo *CSEInfo,
      const MipsPostLegalizerCombinerImplRuleConfig &RuleConfig,
      const MipsSubtarget &STI, MachineDominatorTree *MDT,
      const LegalizerInfo *LI);
 
  static const char *getName() { return "MipsPostLegalizerCombiner"; }
 
  bool tryCombineAll(MachineInstr &I) const override;
 
private:
#define GET_GICOMBINER_CLASS_MEMBERS
#include "MipsGenPostLegalizeGICombiner.inc"
#undef GET_GICOMBINER_CLASS_MEMBERS
};
 
#define GET_GICOMBINER_IMPL
#include "MipsGenPostLegalizeGICombiner.inc"
#undef GET_GICOMBINER_IMPL
 
MipsPostLegalizerCombinerImpl::MipsPostLegalizerCombinerImpl(
    MachineFunction &MF, CombinerInfo &CInfo, GISelValueTracking &VT,
    GISelCSEInfo *CSEInfo,
    const MipsPostLegalizerCombinerImplRuleConfig &RuleConfig,
    const MipsSubtarget &STI, MachineDominatorTree *MDT,
    const LegalizerInfo *LI)
    : Combiner(MF, CInfo, &VT, CSEInfo), RuleConfig(RuleConfig), STI(STI),
      Helper(Observer, B, /*IsPreLegalize*/ false, &VT, MDT, LI),
#define GET_GICOMBINER_CONSTRUCTOR_INITS
#include "MipsGenPostLegalizeGICombiner.inc"
#undef GET_GICOMBINER_CONSTRUCTOR_INITS
{
}
 
// Pass boilerplate
// ================
 
class MipsPostLegalizerCombinerLegacy : public MachineFunctionPass {
public:
  static char ID;
 
  MipsPostLegalizerCombinerLegacy(bool IsOptNone = false);
 
  StringRef getPassName() const override { return "MipsPostLegalizerCombiner"; }
 
  bool runOnMachineFunction(MachineFunction &MF) override;
 
  void getAnalysisUsage(AnalysisUsage &AU) const override;
 
private:
  bool IsOptNone;
};
} // end anonymous namespace
 
void MipsPostLegalizerCombinerLegacy::getAnalysisUsage(
    AnalysisUsage &AU) const {
  AU.setPreservesCFG();
  getSelectionDAGFallbackAnalysisUsage(AU);
  AU.addRequired<GISelValueTrackingAnalysisLegacy>();
  AU.addPreserved<GISelValueTrackingAnalysisLegacy>();
  if (!IsOptNone) {
    AU.addRequired<MachineDominatorTreeWrapperPass>();
  }
  MachineFunctionPass::getAnalysisUsage(AU);
}
 
MipsPostLegalizerCombinerLegacy::MipsPostLegalizerCombinerLegacy(bool IsOptNone)
    : MachineFunctionPass(ID), IsOptNone(IsOptNone) {}
 
static bool
runCombinerOnMachineFunction(MachineFunction &MF, bool IsOptNone,
                             function_ref<bool()> ShouldSkip,
                             function_ref<GISelValueTracking *()> GetVT,
                             function_ref<MachineDominatorTree *()> GetMDT) {
  if (MF.getProperties().hasFailedISel())
    return false;
  const Function &F = MF.getFunction();
  bool EnableOpt =
      MF.getTarget().getOptLevel() != CodeGenOptLevel::None && !ShouldSkip();
 
  MipsPostLegalizerCombinerImplRuleConfig RuleConfig;
  if (!RuleConfig.parseCommandLineOption())
    report_fatal_error("Invalid rule identifier");
 
  const MipsSubtarget &ST = MF.getSubtarget<MipsSubtarget>();
  const MipsLegalizerInfo *LI =
      static_cast<const MipsLegalizerInfo *>(ST.getLegalizerInfo());
 
  GISelValueTracking *VT = GetVT();
  MachineDominatorTree *MDT = IsOptNone ? nullptr : GetMDT();
  CombinerInfo CInfo(/*AllowIllegalOps*/ false, /*ShouldLegalizeIllegal*/ true,
                     LI, EnableOpt, F.hasOptSize(), F.hasMinSize());
  MipsPostLegalizerCombinerImpl Impl(MF, CInfo, *VT, /*CSEInfo*/ nullptr,
                                     RuleConfig, ST, MDT, LI);
  return Impl.combineMachineInstrs();
}
 
char MipsPostLegalizerCombinerLegacy::ID = 0;
INITIALIZE_PASS_BEGIN(MipsPostLegalizerCombinerLegacy, DEBUG_TYPE,
                      "Combine Mips machine instrs after legalization", false,
                      false)
INITIALIZE_PASS_DEPENDENCY(GISelValueTrackingAnalysisLegacy)
INITIALIZE_PASS_END(MipsPostLegalizerCombinerLegacy, DEBUG_TYPE,
                    "Combine Mips machine instrs after legalization", false,
                    false)
 
FunctionPass *llvm::createMipsPostLegalizeCombinerLegacyPass(bool IsOptNone) {
  return new MipsPostLegalizerCombinerLegacy(IsOptNone);
}
 
bool MipsPostLegalizerCombinerLegacy::runOnMachineFunction(
    MachineFunction &MF) {
  return runCombinerOnMachineFunction(
      MF, IsOptNone, [&]() { return skipFunction(MF.getFunction()); },
      [&]() {
        return &getAnalysis<GISelValueTrackingAnalysisLegacy>().get(MF);
      },
      [&]() {
        return &getAnalysis<MachineDominatorTreeWrapperPass>().getDomTree();
      });
}
 
PreservedAnalyses
MipsPostLegalizerCombinerPass::run(MachineFunction &MF,
                                   MachineFunctionAnalysisManager &MFAM) {
  bool Changed = runCombinerOnMachineFunction(
      MF, IsOptNone,
      [&]() {
        return MF.getFunction().hasOptNone() ||
               shouldSkipOptimizationForOptBisect(MF.getFunction());
      },
      [&]() { return &MFAM.getResult<GISelValueTrackingAnalysis>(MF); },
      [&]() { return &MFAM.getResult<MachineDominatorTreeAnalysis>(MF); });
  if (!Changed)
    return PreservedAnalyses::all();
  return getMachineFunctionPassPreservedAnalyses()
      .preserveSet<CFGAnalyses>()
      .preserve<GISelValueTrackingAnalysis>();
}