llvm-for-llvmta/include/llvm/ExecutionEngine/Orc/SpeculateAnalyses.h

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//===-- SpeculateAnalyses.h --*- 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
//
//===----------------------------------------------------------------------===//
// \file
/// Contains the Analyses and Result Interpretation to select likely functions
/// to Speculatively compile before they are called. [Purely Experimentation]
//===----------------------------------------------------------------------===//
#ifndef LLVM_EXECUTIONENGINE_ORC_SPECULATEANALYSES_H
#define LLVM_EXECUTIONENGINE_ORC_SPECULATEANALYSES_H
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/ExecutionEngine/Orc/Core.h"
#include "llvm/ExecutionEngine/Orc/Speculation.h"
#include <vector>
namespace llvm {
namespace orc {
// Provides common code.
class SpeculateQuery {
protected:
void findCalles(const BasicBlock *, DenseSet<StringRef> &);
bool isStraightLine(const Function &F);
public:
using ResultTy = Optional<DenseMap<StringRef, DenseSet<StringRef>>>;
};
// Direct calls in high frequency basic blocks are extracted.
class BlockFreqQuery : public SpeculateQuery {
size_t numBBToGet(size_t);
public:
// Find likely next executables based on IR Block Frequency
ResultTy operator()(Function &F);
};
// This Query generates a sequence of basic blocks which follows the order of
// execution.
// A handful of BB with higher block frequencies are taken, then path to entry
// and end BB are discovered by traversing up & down the CFG.
class SequenceBBQuery : public SpeculateQuery {
struct WalkDirection {
bool Upward = true, Downward = true;
// the block associated contain a call
bool CallerBlock = false;
};
public:
using VisitedBlocksInfoTy = DenseMap<const BasicBlock *, WalkDirection>;
using BlockListTy = SmallVector<const BasicBlock *, 8>;
using BackEdgesInfoTy =
SmallVector<std::pair<const BasicBlock *, const BasicBlock *>, 8>;
using BlockFreqInfoTy =
SmallVector<std::pair<const BasicBlock *, uint64_t>, 8>;
private:
std::size_t getHottestBlocks(std::size_t TotalBlocks);
BlockListTy rearrangeBB(const Function &, const BlockListTy &);
BlockListTy queryCFG(Function &, const BlockListTy &);
void traverseToEntryBlock(const BasicBlock *, const BlockListTy &,
const BackEdgesInfoTy &,
const BranchProbabilityInfo *,
VisitedBlocksInfoTy &);
void traverseToExitBlock(const BasicBlock *, const BlockListTy &,
const BackEdgesInfoTy &,
const BranchProbabilityInfo *,
VisitedBlocksInfoTy &);
public:
ResultTy operator()(Function &F);
};
} // namespace orc
} // namespace llvm
#endif // LLVM_EXECUTIONENGINE_ORC_SPECULATEANALYSES_H