CloneFunction.cpp | Explore in Territory

//===- CloneFunction.cpp - Clone a function into another function ---------===//
//
// 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 implements the CloneFunctionInto interface, which is used as the
// low-level function cloner.  This is used by the CloneFunction and function
// inliner to do the dirty work of copying the body of a function around.
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/DomTreeUpdater.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/AttributeMask.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/ValueMapper.h"
#include <map>
#include <optional>
usingnamespacellvm;

#define DEBUG_TYPE …

/// See comments in Cloning.h.
BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB, ValueToValueMapTy &VMap,
                                  const Twine &NameSuffix, Function *F,
                                  ClonedCodeInfo *CodeInfo,
                                  DebugInfoFinder *DIFinder) { … }

// Clone OldFunc into NewFunc, transforming the old arguments into references to
// VMap values.
//
void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
                             ValueToValueMapTy &VMap,
                             CloneFunctionChangeType Changes,
                             SmallVectorImpl<ReturnInst *> &Returns,
                             const char *NameSuffix, ClonedCodeInfo *CodeInfo,
                             ValueMapTypeRemapper *TypeMapper,
                             ValueMaterializer *Materializer) { … }

/// Return a copy of the specified function and add it to that function's
/// module.  Also, any references specified in the VMap are changed to refer to
/// their mapped value instead of the original one.  If any of the arguments to
/// the function are in the VMap, the arguments are deleted from the resultant
/// function.  The VMap is updated to include mappings from all of the
/// instructions and basicblocks in the function from their old to new values.
///
Function *llvm::CloneFunction(Function *F, ValueToValueMapTy &VMap,
                              ClonedCodeInfo *CodeInfo) { … }

namespace {
/// This is a private class used to implement CloneAndPruneFunctionInto.
struct PruningFunctionCloner { … };
} // namespace

Instruction *
PruningFunctionCloner::cloneInstruction(BasicBlock::const_iterator II) { … }

/// The specified block is found to be reachable, clone it and
/// anything that it can reach.
void PruningFunctionCloner::CloneBlock(
    const BasicBlock *BB, BasicBlock::const_iterator StartingInst,
    std::vector<const BasicBlock *> &ToClone) { … }

/// This works like CloneAndPruneFunctionInto, except that it does not clone the
/// entire function. Instead it starts at an instruction provided by the caller
/// and copies (and prunes) only the code reachable from that instruction.
void llvm::CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc,
                                     const Instruction *StartingInst,
                                     ValueToValueMapTy &VMap,
                                     bool ModuleLevelChanges,
                                     SmallVectorImpl<ReturnInst *> &Returns,
                                     const char *NameSuffix,
                                     ClonedCodeInfo *CodeInfo) { … }

/// This works exactly like CloneFunctionInto,
/// except that it does some simple constant prop and DCE on the fly.  The
/// effect of this is to copy significantly less code in cases where (for
/// example) a function call with constant arguments is inlined, and those
/// constant arguments cause a significant amount of code in the callee to be
/// dead.  Since this doesn't produce an exact copy of the input, it can't be
/// used for things like CloneFunction or CloneModule.
void llvm::CloneAndPruneFunctionInto(
    Function *NewFunc, const Function *OldFunc, ValueToValueMapTy &VMap,
    bool ModuleLevelChanges, SmallVectorImpl<ReturnInst *> &Returns,
    const char *NameSuffix, ClonedCodeInfo *CodeInfo) { … }

/// Remaps instructions in \p Blocks using the mapping in \p VMap.
void llvm::remapInstructionsInBlocks(ArrayRef<BasicBlock *> Blocks,
                                     ValueToValueMapTy &VMap) { … }

/// Clones a loop \p OrigLoop.  Returns the loop and the blocks in \p
/// Blocks.
///
/// Updates LoopInfo and DominatorTree assuming the loop is dominated by block
/// \p LoopDomBB.  Insert the new blocks before block specified in \p Before.
Loop *llvm::cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB,
                                   Loop *OrigLoop, ValueToValueMapTy &VMap,
                                   const Twine &NameSuffix, LoopInfo *LI,
                                   DominatorTree *DT,
                                   SmallVectorImpl<BasicBlock *> &Blocks) { … }

/// Duplicate non-Phi instructions from the beginning of block up to
/// StopAt instruction into a split block between BB and its predecessor.
BasicBlock *llvm::DuplicateInstructionsInSplitBetween(
    BasicBlock *BB, BasicBlock *PredBB, Instruction *StopAt,
    ValueToValueMapTy &ValueMapping, DomTreeUpdater &DTU) { … }

void llvm::cloneNoAliasScopes(ArrayRef<MDNode *> NoAliasDeclScopes,
                              DenseMap<MDNode *, MDNode *> &ClonedScopes,
                              StringRef Ext, LLVMContext &Context) { … }

void llvm::adaptNoAliasScopes(Instruction *I,
                              const DenseMap<MDNode *, MDNode *> &ClonedScopes,
                              LLVMContext &Context) { … }

void llvm::cloneAndAdaptNoAliasScopes(ArrayRef<MDNode *> NoAliasDeclScopes,
                                      ArrayRef<BasicBlock *> NewBlocks,
                                      LLVMContext &Context, StringRef Ext) { … }

void llvm::cloneAndAdaptNoAliasScopes(ArrayRef<MDNode *> NoAliasDeclScopes,
                                      Instruction *IStart, Instruction *IEnd,
                                      LLVMContext &Context, StringRef Ext) { … }

void llvm::identifyNoAliasScopesToClone(
    ArrayRef<BasicBlock *> BBs, SmallVectorImpl<MDNode *> &NoAliasDeclScopes) { … }

void llvm::identifyNoAliasScopesToClone(
    BasicBlock::iterator Start, BasicBlock::iterator End,
    SmallVectorImpl<MDNode *> &NoAliasDeclScopes) { … }
llvm/llvm/lib/Transforms/Utils/CloneFunction.cpp
