llvm-for-llvmta/tools/llvm-reduce/deltas/ReduceMetadata.cpp

128 lines
4.2 KiB
C++

//===- ReduceMetadata.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 two functions used by the Generic Delta Debugging
// Algorithm, which are used to reduce Metadata nodes.
//
//===----------------------------------------------------------------------===//
#include "ReduceMetadata.h"
#include "Delta.h"
#include "llvm/ADT/SmallVector.h"
#include <set>
#include <vector>
using namespace llvm;
/// Adds all Unnamed Metadata Nodes that are inside desired Chunks to set
template <class T>
static void getChunkMetadataNodes(T &MDUser, Oracle &O,
std::set<MDNode *> &SeenNodes,
std::set<MDNode *> &NodesToKeep) {
SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
MDUser.getAllMetadata(MDs);
for (auto &MD : MDs) {
SeenNodes.insert(MD.second);
if (O.shouldKeep())
NodesToKeep.insert(MD.second);
}
}
/// Erases out-of-chunk unnamed metadata nodes from its user
template <class T>
static void eraseMetadataIfOutsideChunk(T &MDUser,
const std::set<MDNode *> &NodesToKeep) {
SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
MDUser.getAllMetadata(MDs);
for (int I = 0, E = MDs.size(); I != E; ++I)
if (!NodesToKeep.count(MDs[I].second))
MDUser.setMetadata(I, NULL);
}
/// Removes all the Named and Unnamed Metadata Nodes, as well as any debug
/// functions that aren't inside the desired Chunks.
static void extractMetadataFromModule(const std::vector<Chunk> &ChunksToKeep,
Module *Program) {
Oracle O(ChunksToKeep);
std::set<MDNode *> SeenNodes;
std::set<MDNode *> NodesToKeep;
// Add chunk MDNodes used by GVs, Functions, and Instructions to set
for (auto &GV : Program->globals())
getChunkMetadataNodes(GV, O, SeenNodes, NodesToKeep);
for (auto &F : *Program) {
getChunkMetadataNodes(F, O, SeenNodes, NodesToKeep);
for (auto &BB : F)
for (auto &Inst : BB)
getChunkMetadataNodes(Inst, O, SeenNodes, NodesToKeep);
}
// Once more, go over metadata nodes, but deleting the ones outside chunks
for (auto &GV : Program->globals())
eraseMetadataIfOutsideChunk(GV, NodesToKeep);
for (auto &F : *Program) {
eraseMetadataIfOutsideChunk(F, NodesToKeep);
for (auto &BB : F)
for (auto &Inst : BB)
eraseMetadataIfOutsideChunk(Inst, NodesToKeep);
}
// Get out-of-chunk Named metadata nodes
std::vector<NamedMDNode *> NamedNodesToDelete;
for (auto &MD : Program->named_metadata())
if (!O.shouldKeep())
NamedNodesToDelete.push_back(&MD);
for (auto *NN : NamedNodesToDelete) {
for (int I = 0, E = NN->getNumOperands(); I != E; ++I)
NN->setOperand(I, NULL);
NN->eraseFromParent();
}
}
// Gets unnamed metadata nodes used by a given instruction/GV/function and adds
// them to the set of seen nodes
template <class T>
static void addMetadataToSet(T &MDUser, std::set<MDNode *> &UnnamedNodes) {
SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
MDUser.getAllMetadata(MDs);
for (auto &MD : MDs)
UnnamedNodes.insert(MD.second);
}
/// Returns the amount of Named and Unnamed Metadata Nodes
static int countMetadataTargets(Module *Program) {
std::set<MDNode *> UnnamedNodes;
int NamedMetadataNodes = Program->named_metadata_size();
// Get metadata nodes used by globals
for (auto &GV : Program->globals())
addMetadataToSet(GV, UnnamedNodes);
// Do the same for nodes used by functions & instructions
for (auto &F : *Program) {
addMetadataToSet(F, UnnamedNodes);
for (auto &BB : F)
for (auto &I : BB)
addMetadataToSet(I, UnnamedNodes);
}
return UnnamedNodes.size() + NamedMetadataNodes;
}
void llvm::reduceMetadataDeltaPass(TestRunner &Test) {
outs() << "*** Reducing Metadata...\n";
int MDCount = countMetadataTargets(Test.getProgram());
runDeltaPass(Test, MDCount, extractMetadataFromModule);
outs() << "----------------------------\n";
}