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-rw-r--r--tools/llvm-reduce/deltas/ReduceGlobalVars.cpp74
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diff --git a/tools/llvm-reduce/deltas/ReduceGlobalVars.cpp b/tools/llvm-reduce/deltas/ReduceGlobalVars.cpp
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+//===- 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);
+}