Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===-- BasicBlockSectionsProfileReader.h - BB sections profile reader pass ==//

//

// 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 pass creates the basic block cluster info by reading the basic block

// sections profile. The cluster info will be used by the basic-block-sections

// pass to arrange basic blocks in their sections.

//

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

#ifndef LLVM_CODEGEN_BASICBLOCKSECTIONSPROFILEREADER_H

#define LLVM_CODEGEN_BASICBLOCKSECTIONSPROFILEREADER_H

#include "llvm/ADT/SmallSet.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/ADT/StringMap.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/InitializePasses.h"

#include "llvm/Pass.h"

#include "llvm/Support/Error.h"

#include "llvm/Support/LineIterator.h"

#include "llvm/Support/MemoryBuffer.h"

using namespace llvm;

namespace llvm {

// The cluster information for a machine basic block.

struct BBClusterInfo {

  // Unique ID for this basic block.

  unsigned BBID;

  // Cluster ID this basic block belongs to.

  unsigned ClusterID;

  // Position of basic block within the cluster.

  unsigned PositionInCluster;

};

using ProgramBBClusterInfoMapTy = StringMap<SmallVector<BBClusterInfo>>;

class BasicBlockSectionsProfileReader : public ImmutablePass {

public:

  static char ID;

  BasicBlockSectionsProfileReader(const MemoryBuffer *Buf)

      : ImmutablePass(ID), MBuf(Buf) {

    initializeBasicBlockSectionsProfileReaderPass(

        *PassRegistry::getPassRegistry());

  };

  BasicBlockSectionsProfileReader() : ImmutablePass(ID) {

    initializeBasicBlockSectionsProfileReaderPass(

        *PassRegistry::getPassRegistry());

  }

  StringRef getPassName() const override {

    return "Basic Block Sections Profile Reader";

  }

  // Returns true if basic block sections profile exist for function \p

  // FuncName.

  bool isFunctionHot(StringRef FuncName) const;

  // Returns a pair with first element representing whether basic block sections

  // profile exist for the function \p FuncName, and the second element

  // representing the basic block sections profile (cluster info) for this

  // function. If the first element is true and the second element is empty, it

  // means unique basic block sections are desired for all basic blocks of the

  // function.

  std::pair<bool, SmallVector<BBClusterInfo>>

  getBBClusterInfoForFunction(StringRef FuncName) const;

  /// Read profiles of basic blocks if available here.

  void initializePass() override;

private:

  StringRef getAliasName(StringRef FuncName) const {

    auto R = FuncAliasMap.find(FuncName);

    return R == FuncAliasMap.end() ? FuncName : R->second;

  }

  // This contains the basic-block-sections profile.

  const MemoryBuffer *MBuf = nullptr;

  // This encapsulates the BB cluster information for the whole program.

  //

  // For every function name, it contains the cluster information for (all or

  // some of) its basic blocks. The cluster information for every basic block

  // includes its cluster ID along with the position of the basic block in that

  // cluster.

  ProgramBBClusterInfoMapTy ProgramBBClusterInfo;

  // Some functions have alias names. We use this map to find the main alias

  // name for which we have mapping in ProgramBBClusterInfo.

  StringMap<StringRef> FuncAliasMap;

};

// Creates a BasicBlockSectionsProfileReader pass to parse the basic block

// sections profile. \p Buf is a memory buffer that contains the list of

// functions and basic block ids to selectively enable basic block sections.

ImmutablePass *

createBasicBlockSectionsProfileReaderPass(const MemoryBuffer *Buf);

} // namespace llvm

#endif // LLVM_CODEGEN_BASICBLOCKSECTIONSPROFILEREADER_H