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//===- PruneUnprofitable.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
//
//===----------------------------------------------------------------------===//
//
// Mark a SCoP as unfeasible if not deemed profitable to optimize.
//
//===----------------------------------------------------------------------===//
#include "polly/PruneUnprofitable.h"
#include "polly/ScopDetection.h"
#include "polly/ScopInfo.h"
#include "polly/ScopPass.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
using namespace polly;
#include "polly/Support/PollyDebug.h"
#define DEBUG_TYPE "polly-prune-unprofitable"
namespace {
STATISTIC(ScopsProcessed,
"Number of SCoPs considered for unprofitability pruning");
STATISTIC(ScopsPruned, "Number of pruned SCoPs because it they cannot be "
"optimized in a significant way");
STATISTIC(ScopsSurvived, "Number of SCoPs after pruning");
STATISTIC(NumPrunedLoops, "Number of pruned loops");
STATISTIC(NumPrunedBoxedLoops, "Number of pruned boxed loops");
STATISTIC(NumPrunedAffineLoops, "Number of pruned affine loops");
STATISTIC(NumLoopsInScop, "Number of loops in scops after pruning");
STATISTIC(NumBoxedLoops, "Number of boxed loops in SCoPs after pruning");
STATISTIC(NumAffineLoops, "Number of affine loops in SCoPs after pruning");
static void updateStatistics(Scop &S, bool Pruned) {
Scop::ScopStatistics ScopStats = S.getStatistics();
if (Pruned) {
ScopsPruned++;
NumPrunedLoops += ScopStats.NumAffineLoops + ScopStats.NumBoxedLoops;
NumPrunedBoxedLoops += ScopStats.NumBoxedLoops;
NumPrunedAffineLoops += ScopStats.NumAffineLoops;
} else {
ScopsSurvived++;
NumLoopsInScop += ScopStats.NumAffineLoops + ScopStats.NumBoxedLoops;
NumBoxedLoops += ScopStats.NumBoxedLoops;
NumAffineLoops += ScopStats.NumAffineLoops;
}
}
static bool runPruneUnprofitable(Scop &S) {
if (PollyProcessUnprofitable) {
POLLY_DEBUG(
dbgs() << "NOTE: -polly-process-unprofitable active, won't prune "
"anything\n");
return false;
}
ScopsProcessed++;
if (!S.isProfitable(true)) {
POLLY_DEBUG(
dbgs() << "SCoP pruned because it probably cannot be optimized in "
"a significant way\n");
S.invalidate(PROFITABLE, DebugLoc());
updateStatistics(S, true);
} else {
updateStatistics(S, false);
}
return false;
}
class PruneUnprofitableWrapperPass final : public ScopPass {
public:
static char ID;
explicit PruneUnprofitableWrapperPass() : ScopPass(ID) {}
PruneUnprofitableWrapperPass(const PruneUnprofitableWrapperPass &) = delete;
PruneUnprofitableWrapperPass &
operator=(const PruneUnprofitableWrapperPass &) = delete;
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<ScopInfoRegionPass>();
AU.setPreservesAll();
}
bool runOnScop(Scop &S) override { return runPruneUnprofitable(S); }
};
} // namespace
char PruneUnprofitableWrapperPass::ID;
Pass *polly::createPruneUnprofitableWrapperPass() {
return new PruneUnprofitableWrapperPass();
}
INITIALIZE_PASS_BEGIN(PruneUnprofitableWrapperPass, "polly-prune-unprofitable",
"Polly - Prune unprofitable SCoPs", false, false)
INITIALIZE_PASS_END(PruneUnprofitableWrapperPass, "polly-prune-unprofitable",
"Polly - Prune unprofitable SCoPs", false, false)
llvm::PreservedAnalyses
PruneUnprofitablePass::run(Scop &S, ScopAnalysisManager &SAM,
ScopStandardAnalysisResults &SAR, SPMUpdater &U) {
bool Changed = runPruneUnprofitable(S);
if (!Changed)
return PreservedAnalyses::all();
PreservedAnalyses PA;
PA.preserveSet<AllAnalysesOn<Module>>();
PA.preserveSet<AllAnalysesOn<Function>>();
PA.preserveSet<AllAnalysesOn<Loop>>();
return PA;
}