llvm/llvm/include/llvm/Transforms/Utils/CodeExtractor.h

//===- Transform/Utils/CodeExtractor.h - Code extraction util ---*- 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
//
//===----------------------------------------------------------------------===//
//
// A utility to support extracting code from one function into its own
// stand-alone function.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TRANSFORMS_UTILS_CODEEXTRACTOR_H
#define LLVM_TRANSFORMS_UTILS_CODEEXTRACTOR_H

#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SetVector.h"
#include <limits>

namespace llvm {

template <typename PtrType> class SmallPtrSetImpl;
class AllocaInst;
class BasicBlock;
class BlockFrequency;
class BlockFrequencyInfo;
class BranchProbabilityInfo;
class AssumptionCache;
class CallInst;
class DominatorTree;
class Function;
class Instruction;
class Module;
class Type;
class Value;

/// A cache for the CodeExtractor analysis. The operation \ref
/// CodeExtractor::extractCodeRegion is guaranteed not to invalidate this
/// object. This object should conservatively be considered invalid if any
/// other mutating operations on the IR occur.
///
/// Constructing this object is O(n) in the size of the function.
class CodeExtractorAnalysisCache { … };

  /// Utility class for extracting code into a new function.
  ///
  /// This utility provides a simple interface for extracting some sequence of
  /// code into its own function, replacing it with a call to that function. It
  /// also provides various methods to query about the nature and result of
  /// such a transformation.
  ///
  /// The rough algorithm used is:
  /// 1) Find both the inputs and outputs for the extracted region.
  /// 2) Pass the inputs as arguments, remapping them within the extracted
  ///    function to arguments.
  /// 3) Add allocas for any scalar outputs, adding all of the outputs' allocas
  ///    as arguments, and inserting stores to the arguments for any scalars.
  class CodeExtractor { … };

} // end namespace llvm

#endif // LLVM_TRANSFORMS_UTILS_CODEEXTRACTOR_H