63 lines
2.2 KiB
C++
63 lines
2.2 KiB
C++
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//===- ReduceSpecialGlobals.cpp - Specialized Delta Pass ------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements a function which calls the Generic Delta pass in order
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// to reduce special globals, like @llvm.used, in the provided Module.
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//
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// For more details about special globals, see
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// https://llvm.org/docs/LangRef.html#intrinsic-global-variables
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//
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//===----------------------------------------------------------------------===//
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#include "ReduceSpecialGlobals.h"
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#include "Delta.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/GlobalValue.h"
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using namespace llvm;
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static StringRef SpecialGlobalNames[] = {"llvm.used", "llvm.compiler.used"};
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/// Removes all special globals aren't inside any of the
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/// desired Chunks.
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static void
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extractSpecialGlobalsFromModule(const std::vector<Chunk> &ChunksToKeep,
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Module *Program) {
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Oracle O(ChunksToKeep);
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for (StringRef Name : SpecialGlobalNames) {
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if (auto *Used = Program->getNamedGlobal(Name)) {
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Used->replaceAllUsesWith(UndefValue::get(Used->getType()));
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Used->eraseFromParent();
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}
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}
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}
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/// Counts the amount of special globals and prints their
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/// respective name & index
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static int countSpecialGlobals(Module *Program) {
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// TODO: Silence index with --quiet flag
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errs() << "----------------------------\n";
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errs() << "Special Globals Index Reference:\n";
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int Count = 0;
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for (StringRef Name : SpecialGlobalNames) {
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if (auto *Used = Program->getNamedGlobal(Name))
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errs() << "\t" << ++Count << ": " << Used->getName() << "\n";
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}
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errs() << "----------------------------\n";
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return Count;
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}
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void llvm::reduceSpecialGlobalsDeltaPass(TestRunner &Test) {
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errs() << "*** Reducing Special Globals ...\n";
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int Functions = countSpecialGlobals(Test.getProgram());
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runDeltaPass(Test, Functions, extractSpecialGlobalsFromModule);
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errs() << "----------------------------\n";
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}
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