llvm-project/llvm/lib/Transforms/AggressiveInstCombine/AggressiveInstCombine.cpp

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4.5 KiB
C++

//===- AggressiveInstCombine.cpp ------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the aggressive expression pattern combiner classes.
// Currently, it handles expression patterns for:
// * Truncate instruction
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/AggressiveInstCombine/AggressiveInstCombine.h"
#include "AggressiveInstCombineInternal.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/Pass.h"
using namespace llvm;
#define DEBUG_TYPE "aggressive-instcombine"
namespace {
/// Contains expression pattern combiner logic.
/// This class provides both the logic to combine expression patterns and
/// combine them. It differs from InstCombiner class in that each pattern
/// combiner runs only once as opposed to InstCombine's multi-iteration,
/// which allows pattern combiner to have higher complexity than the O(1)
/// required by the instruction combiner.
class AggressiveInstCombinerLegacyPass : public FunctionPass {
public:
static char ID; // Pass identification, replacement for typeid
AggressiveInstCombinerLegacyPass() : FunctionPass(ID) {
initializeAggressiveInstCombinerLegacyPassPass(
*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const override;
/// Run all expression pattern optimizations on the given /p F function.
///
/// \param F function to optimize.
/// \returns true if the IR is changed.
bool runOnFunction(Function &F) override;
};
} // namespace
void AggressiveInstCombinerLegacyPass::getAnalysisUsage(
AnalysisUsage &AU) const {
AU.setPreservesCFG();
AU.addRequired<DominatorTreeWrapperPass>();
AU.addRequired<TargetLibraryInfoWrapperPass>();
AU.addPreserved<AAResultsWrapperPass>();
AU.addPreserved<BasicAAWrapperPass>();
AU.addPreserved<DominatorTreeWrapperPass>();
AU.addPreserved<GlobalsAAWrapperPass>();
}
bool AggressiveInstCombinerLegacyPass::runOnFunction(Function &F) {
auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
auto &TLI = getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
auto &DL = F.getParent()->getDataLayout();
bool MadeIRChange = false;
// Handle TruncInst patterns
TruncInstCombine TIC(TLI, DL, DT);
MadeIRChange |= TIC.run(F);
// TODO: add more patterns to handle...
return MadeIRChange;
}
PreservedAnalyses AggressiveInstCombinePass::run(Function &F,
FunctionAnalysisManager &AM) {
auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
auto &DL = F.getParent()->getDataLayout();
bool MadeIRChange = false;
// Handle TruncInst patterns
TruncInstCombine TIC(TLI, DL, DT);
MadeIRChange |= TIC.run(F);
if (!MadeIRChange)
// No changes, all analyses are preserved.
return PreservedAnalyses::all();
// Mark all the analyses that instcombine updates as preserved.
PreservedAnalyses PA;
PA.preserveSet<CFGAnalyses>();
PA.preserve<AAManager>();
PA.preserve<GlobalsAA>();
return PA;
}
char AggressiveInstCombinerLegacyPass::ID = 0;
INITIALIZE_PASS_BEGIN(AggressiveInstCombinerLegacyPass,
"aggressive-instcombine",
"Combine pattern based expressions", false, false)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
INITIALIZE_PASS_END(AggressiveInstCombinerLegacyPass, "aggressive-instcombine",
"Combine pattern based expressions", false, false)
// Initialization Routines
void llvm::initializeAggressiveInstCombine(PassRegistry &Registry) {
initializeAggressiveInstCombinerLegacyPassPass(Registry);
}
void LLVMInitializeAggressiveInstCombiner(LLVMPassRegistryRef R) {
initializeAggressiveInstCombinerLegacyPassPass(*unwrap(R));
}
FunctionPass *llvm::createAggressiveInstCombinerPass() {
return new AggressiveInstCombinerLegacyPass();
}
void LLVMAddAggressiveInstCombinerPass(LLVMPassManagerRef PM) {
unwrap(PM)->add(createAggressiveInstCombinerPass());
}