Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===- AssumeBundleBuilder.h - utils to build assume bundles ----*- C++ -*-===//

//

// 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 contain tools to preserve informations. They should be used before

// performing a transformation that may move and delete instructions as those

// transformation may destroy or worsen information that can be derived from the

// IR.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_TRANSFORMS_UTILS_ASSUMEBUNDLEBUILDER_H

#define LLVM_TRANSFORMS_UTILS_ASSUMEBUNDLEBUILDER_H

#include "llvm/Analysis/AssumeBundleQueries.h"

#include "llvm/IR/PassManager.h"

namespace llvm {

class AssumeInst;

class Function;

class FunctionPass;

class Instruction;

class AssumptionCache;

class DominatorTree;

/// Build a call to llvm.assume to preserve informations that can be derived

/// from the given instruction.

/// If no information derived from \p I, this call returns null.

/// The returned instruction is not inserted anywhere.

AssumeInst *buildAssumeFromInst(Instruction *I);

/// Calls BuildAssumeFromInst and if the resulting llvm.assume is valid insert

/// if before I. This is usually what need to be done to salvage the knowledge

/// contained in the instruction I.

/// The AssumptionCache must be provided if it is available or the cache may

/// become silently be invalid.

/// The DominatorTree can optionally be provided to enable cross-block

/// reasoning.

void salvageKnowledge(Instruction *I, AssumptionCache *AC = nullptr,

                      DominatorTree *DT = nullptr);

/// Build and return a new assume created from the provided knowledge

/// if the knowledge in the assume is fully redundant this will return nullptr

AssumeInst *buildAssumeFromKnowledge(ArrayRef<RetainedKnowledge> Knowledge,

                                     Instruction *CtxI,

                                     AssumptionCache *AC = nullptr,

                                     DominatorTree *DT = nullptr);

/// This pass attempts to minimize the number of assume without loosing any

/// information.

struct AssumeSimplifyPass : public PassInfoMixin<AssumeSimplifyPass> {

  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);

};

FunctionPass *createAssumeSimplifyPass();

/// This pass will try to build an llvm.assume for every instruction in the

/// function. Its main purpose is testing.

struct AssumeBuilderPass : public PassInfoMixin<AssumeBuilderPass> {

  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);

};

/// canonicalize the RetainedKnowledge RK. it is assumed that RK is part of

/// Assume. This will return an empty RetainedKnowledge if the knowledge is

/// useless.

RetainedKnowledge simplifyRetainedKnowledge(AssumeInst *Assume,

                                            RetainedKnowledge RK,

                                            AssumptionCache *AC,

                                            DominatorTree *DT);

} // namespace llvm

#endif