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Diffstat (limited to 'tools/llvm-reduce/deltas/ReduceGlobalVars.cpp')
-rw-r--r-- | tools/llvm-reduce/deltas/ReduceGlobalVars.cpp | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/tools/llvm-reduce/deltas/ReduceGlobalVars.cpp b/tools/llvm-reduce/deltas/ReduceGlobalVars.cpp new file mode 100644 index 000000000000..5732208ee0a9 --- /dev/null +++ b/tools/llvm-reduce/deltas/ReduceGlobalVars.cpp @@ -0,0 +1,74 @@ +//===- ReduceGlobalVars.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 initialized Global Variables in the provided Module. +// +//===----------------------------------------------------------------------===// + +#include "ReduceGlobalVars.h" +#include <set> + +using namespace llvm; + +/// Removes all the Initialized GVs that aren't inside the desired Chunks. +static void extractGVsFromModule(std::vector<Chunk> ChunksToKeep, + Module *Program) { + // Get GVs inside desired chunks + std::set<GlobalVariable *> GVsToKeep; + int I = 0, GVCount = 0; + for (auto &GV : Program->globals()) + if (GV.hasInitializer() && I < (int)ChunksToKeep.size()) { + if (ChunksToKeep[I].contains(++GVCount)) + GVsToKeep.insert(&GV); + if (GVCount == ChunksToKeep[I].end) + ++I; + } + + // Delete out-of-chunk GVs and their uses + std::vector<GlobalVariable *> ToRemove; + std::vector<Instruction *> InstToRemove; + for (auto &GV : Program->globals()) + if (GV.hasInitializer() && !GVsToKeep.count(&GV)) { + for (auto U : GV.users()) + if (auto *Inst = dyn_cast<Instruction>(U)) + InstToRemove.push_back(Inst); + + GV.replaceAllUsesWith(UndefValue::get(GV.getType())); + ToRemove.push_back(&GV); + } + + // Delete Instruction uses of unwanted GVs + for (auto *Inst : InstToRemove) { + Inst->replaceAllUsesWith(UndefValue::get(Inst->getType())); + Inst->eraseFromParent(); + } + + for (auto *GV : ToRemove) + GV->eraseFromParent(); +} + +/// Counts the amount of initialized GVs and displays their +/// respective name & index +static int countGVs(Module *Program) { + // TODO: Silence index with --quiet flag + outs() << "----------------------------\n"; + outs() << "GlobalVariable Index Reference:\n"; + int GVCount = 0; + for (auto &GV : Program->globals()) + if (GV.hasInitializer()) + outs() << "\t" << ++GVCount << ": " << GV.getName() << "\n"; + outs() << "----------------------------\n"; + return GVCount; +} + +void llvm::reduceGlobalsDeltaPass(TestRunner &Test) { + outs() << "*** Reducing GVs...\n"; + int GVCount = countGVs(Test.getProgram()); + runDeltaPass(Test, GVCount, extractGVsFromModule); +} |