InlineSimple.cpp

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//===- InlineSimple.cpp - Code to perform simple function inlining --------===//
//
// 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 bottom-up inlining of functions into callees.
//
//===----------------------------------------------------------------------===//
 
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/InlineCost.h"
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/InitializePasses.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/IPO/Inliner.h"
 
using namespace llvm;
 
#define DEBUG_TYPE "inline"
 
namespace {
 
/// Actual inliner pass implementation.
///
/// The common implementation of the inlining logic is shared between this
/// inliner pass and the always inliner pass. The two passes use different cost
/// analyses to determine when to inline.
class SimpleInliner : public LegacyInlinerBase {
 
  InlineParams Params;
 
public:
  SimpleInliner() : LegacyInlinerBase(ID), Params(llvm::getInlineParams()) {
    initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
  }
 
  explicit SimpleInliner(InlineParams Params)
      : LegacyInlinerBase(ID), Params(std::move(Params)) {
    initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
  }
 
  static char ID; // Pass identification, replacement for typeid
 
  InlineCost getInlineCost(CallBase &CB) override {
    Function *Callee = CB.getCalledFunction();
    TargetTransformInfo &TTI = TTIWP->getTTI(*Callee);
 
    bool RemarksEnabled = false;
    const auto &BBs = CB.getCaller()->getBasicBlockList();
    if (!BBs.empty()) {
      auto DI = OptimizationRemark(DEBUG_TYPE, "", DebugLoc(), &BBs.front());
      if (DI.isEnabled())
        RemarksEnabled = true;
    }
    OptimizationRemarkEmitter ORE(CB.getCaller());
 
    std::function<AssumptionCache &(Function &)> GetAssumptionCache =
        [&](Function &F) -> AssumptionCache & {
      return ACT->getAssumptionCache(F);
    };
    return llvm::getInlineCost(CB, Params, TTI, GetAssumptionCache, GetTLI,
                               /*GetBFI=*/nullptr, PSI,
                               RemarksEnabled ? &ORE : nullptr);
  }
 
  bool runOnSCC(CallGraphSCC &SCC) override;
  void getAnalysisUsage(AnalysisUsage &AU) const override;
 
private:
  TargetTransformInfoWrapperPass *TTIWP;
 
};
 
} // end anonymous namespace
 
char SimpleInliner::ID = 0;
INITIALIZE_PASS_BEGIN(SimpleInliner, "inline", "Function Integration/Inlining",
                      false, false)
INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
INITIALIZE_PASS_END(SimpleInliner, "inline", "Function Integration/Inlining",
                    false, false)
 
Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
 
Pass *llvm::createFunctionInliningPass(int Threshold) {
  return new SimpleInliner(llvm::getInlineParams(Threshold));
}
 
Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
                                       unsigned SizeOptLevel,
                                       bool DisableInlineHotCallSite) {
  auto Param = llvm::getInlineParams(OptLevel, SizeOptLevel);
  if (DisableInlineHotCallSite)
    Param.HotCallSiteThreshold = 0;
  return new SimpleInliner(Param);
}
 
Pass *llvm::createFunctionInliningPass(InlineParams &Params) {
  return new SimpleInliner(Params);
}
 
bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
  TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
  return LegacyInlinerBase::runOnSCC(SCC);
}
 
void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
  AU.addRequired<TargetTransformInfoWrapperPass>();
  LegacyInlinerBase::getAnalysisUsage(AU);
}