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Diffstat (limited to 'tools/llvm-reduce/deltas/ReduceArguments.cpp')
-rw-r--r-- | tools/llvm-reduce/deltas/ReduceArguments.cpp | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/tools/llvm-reduce/deltas/ReduceArguments.cpp b/tools/llvm-reduce/deltas/ReduceArguments.cpp new file mode 100644 index 000000000000..f5f14b83f42c --- /dev/null +++ b/tools/llvm-reduce/deltas/ReduceArguments.cpp @@ -0,0 +1,125 @@ +//===- ReduceArguments.cpp - Specialized Delta 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 file implements a function which calls the Generic Delta pass in order +// to reduce uninteresting Arguments from defined functions. +// +//===----------------------------------------------------------------------===// + +#include "ReduceArguments.h" +#include "Delta.h" +#include "llvm/ADT/SmallVector.h" +#include <set> +#include <vector> + +using namespace llvm; + +/// Goes over OldF calls and replaces them with a call to NewF +static void replaceFunctionCalls(Function &OldF, Function &NewF, + const std::set<int> &ArgIndexesToKeep) { + const auto &Users = OldF.users(); + for (auto I = Users.begin(), E = Users.end(); I != E; ) + if (auto *CI = dyn_cast<CallInst>(*I++)) { + SmallVector<Value *, 8> Args; + for (auto ArgI = CI->arg_begin(), E = CI->arg_end(); ArgI != E; ++ArgI) + if (ArgIndexesToKeep.count(ArgI - CI->arg_begin())) + Args.push_back(*ArgI); + + CallInst *NewCI = CallInst::Create(&NewF, Args); + NewCI->setCallingConv(NewF.getCallingConv()); + if (!CI->use_empty()) + CI->replaceAllUsesWith(NewCI); + ReplaceInstWithInst(CI, NewCI); + } +} + +/// Removes out-of-chunk arguments from functions, and modifies their calls +/// accordingly. It also removes allocations of out-of-chunk arguments. +static void extractArgumentsFromModule(std::vector<Chunk> ChunksToKeep, + Module *Program) { + int I = 0, ArgCount = 0; + std::set<Argument *> ArgsToKeep; + std::vector<Function *> Funcs; + // Get inside-chunk arguments, as well as their parent function + for (auto &F : *Program) + if (!F.isDeclaration()) { + Funcs.push_back(&F); + for (auto &A : F.args()) + if (I < (int)ChunksToKeep.size()) { + if (ChunksToKeep[I].contains(++ArgCount)) + ArgsToKeep.insert(&A); + if (ChunksToKeep[I].end == ArgCount) + ++I; + } + } + + for (auto *F : Funcs) { + ValueToValueMapTy VMap; + std::vector<Instruction *> InstToDelete; + for (auto &A : F->args()) + if (!ArgsToKeep.count(&A)) { + // By adding undesired arguments to the VMap, CloneFunction will remove + // them from the resulting Function + VMap[&A] = UndefValue::get(A.getType()); + for (auto *U : A.users()) + if (auto *I = dyn_cast<Instruction>(*&U)) + InstToDelete.push_back(I); + } + // Delete any instruction that uses the argument + for (auto *I : InstToDelete) { + I->replaceAllUsesWith(UndefValue::get(I->getType())); + I->eraseFromParent(); + } + + // No arguments to reduce + if (VMap.empty()) + continue; + + std::set<int> ArgIndexesToKeep; + int ArgI = 0; + for (auto &Arg : F->args()) + if (ArgsToKeep.count(&Arg)) + ArgIndexesToKeep.insert(++ArgI); + + auto *ClonedFunc = CloneFunction(F, VMap); + // In order to preserve function order, we move Clone after old Function + ClonedFunc->removeFromParent(); + Program->getFunctionList().insertAfter(F->getIterator(), ClonedFunc); + + replaceFunctionCalls(*F, *ClonedFunc, ArgIndexesToKeep); + // Rename Cloned Function to Old's name + std::string FName = F->getName(); + F->eraseFromParent(); + ClonedFunc->setName(FName); + } +} + +/// Counts the amount of arguments in non-declaration functions and prints their +/// respective name, index, and parent function name +static int countArguments(Module *Program) { + // TODO: Silence index with --quiet flag + outs() << "----------------------------\n"; + outs() << "Param Index Reference:\n"; + int ArgsCount = 0; + for (auto &F : *Program) + if (!F.isDeclaration() && F.arg_size()) { + outs() << " " << F.getName() << "\n"; + for (auto &A : F.args()) + outs() << "\t" << ++ArgsCount << ": " << A.getName() << "\n"; + + outs() << "----------------------------\n"; + } + + return ArgsCount; +} + +void llvm::reduceArgumentsDeltaPass(TestRunner &Test) { + outs() << "*** Reducing Arguments...\n"; + int ArgCount = countArguments(Test.getProgram()); + runDeltaPass(Test, ArgCount, extractArgumentsFromModule); +} |