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//===- LoopPass.h - LoopPass class ----------------------------------------===//
//
// 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 defines LoopPass class. All loop optimization
// and transformation passes are derived from LoopPass.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_LOOPPASS_H
#define LLVM_ANALYSIS_LOOPPASS_H
#include "llvm/IR/LegacyPassManagers.h"
#include "llvm/Pass.h"
#include <deque>
namespace llvm {
class Loop;
class LoopInfo;
class LPPassManager;
class Function;
class LoopPass : public Pass {
public:
explicit LoopPass(char &pid) : Pass(PT_Loop, pid) {}
/// getPrinterPass - Get a pass to print the function corresponding
/// to a Loop.
Pass *createPrinterPass(raw_ostream &O,
const std::string &Banner) const override;
// runOnLoop - This method should be implemented by the subclass to perform
// whatever action is necessary for the specified Loop.
virtual bool runOnLoop(Loop *L, LPPassManager &LPM) = 0;
using llvm::Pass::doInitialization;
using llvm::Pass::doFinalization;
// Initialization and finalization hooks.
virtual bool doInitialization(Loop *L, LPPassManager &LPM) {
return false;
}
// Finalization hook does not supply Loop because at this time
// loop nest is completely different.
virtual bool doFinalization() { return false; }
// Check if this pass is suitable for the current LPPassManager, if
// available. This pass P is not suitable for a LPPassManager if P
// is not preserving higher level analysis info used by other
// LPPassManager passes. In such case, pop LPPassManager from the
// stack. This will force assignPassManager() to create new
// LPPassManger as expected.
void preparePassManager(PMStack &PMS) override;
/// Assign pass manager to manage this pass
void assignPassManager(PMStack &PMS, PassManagerType PMT) override;
/// Return what kind of Pass Manager can manage this pass.
PassManagerType getPotentialPassManagerType() const override {
return PMT_LoopPassManager;
}
protected:
/// Optional passes call this function to check whether the pass should be
/// skipped. This is the case when Attribute::OptimizeNone is set or when
/// optimization bisect is over the limit.
bool skipLoop(const Loop *L) const;
};
class LPPassManager : public FunctionPass, public PMDataManager {
public:
static char ID;
explicit LPPassManager();
/// run - Execute all of the passes scheduled for execution. Keep track of
/// whether any of the passes modifies the module, and if so, return true.
bool runOnFunction(Function &F) override;
/// Pass Manager itself does not invalidate any analysis info.
// LPPassManager needs LoopInfo.
void getAnalysisUsage(AnalysisUsage &Info) const override;
StringRef getPassName() const override { return "Loop Pass Manager"; }
PMDataManager *getAsPMDataManager() override { return this; }
Pass *getAsPass() override { return this; }
/// Print passes managed by this manager
void dumpPassStructure(unsigned Offset) override;
LoopPass *getContainedPass(unsigned N) {
assert(N < PassVector.size() && "Pass number out of range!");
LoopPass *LP = static_cast<LoopPass *>(PassVector[N]);
return LP;
}
PassManagerType getPassManagerType() const override {
return PMT_LoopPassManager;
}
public:
// Add a new loop into the loop queue.
void addLoop(Loop &L);
// Mark \p L as deleted.
void markLoopAsDeleted(Loop &L);
private:
std::deque<Loop *> LQ;
LoopInfo *LI;
Loop *CurrentLoop;
bool CurrentLoopDeleted;
};
// This pass is required by the LCSSA transformation. It is used inside
// LPPassManager to check if current pass preserves LCSSA form, and if it does
// pass manager calls lcssa verification for the current loop.
struct LCSSAVerificationPass : public FunctionPass {
static char ID;
LCSSAVerificationPass();
bool runOnFunction(Function &F) override { return false; }
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesAll();
}
};
} // End llvm namespace
#endif
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