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IR: Eliminate non-determinism in the module summary analysis.

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Also make the summary ref and call graph vectors immutable. This means
a smaller API surface and fewer places to audit for non-determinism.

Differential Revision: https://reviews.llvm.org/D27875

llvm-svn: 290200
This commit is contained in:
Peter Collingbourne
2016-12-20 21:12:28 +00:00
parent b29dd0107c
commit 0c30f089d5
7 changed files with 132 additions and 172 deletions
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129
llvm/lib/Bitcode/Reader/BitcodeReader.cpp
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@@ -668,14 +668,15 @@ private:
Error parseValueSymbolTable(
uint64_t Offset,
DenseMap<unsigned, GlobalValue::LinkageTypes> &ValueIdToLinkageMap);
std::vector<ValueInfo> makeRefList(ArrayRef<uint64_t> Record);
std::vector<FunctionSummary::EdgeTy> makeCallList(ArrayRef<uint64_t> Record,
bool IsOldProfileFormat,
bool HasProfile);
Error parseEntireSummary(StringRef ModulePath);
Error parseModuleStringTable();
std::pair<GlobalValue::GUID, GlobalValue::GUID>
std::pair<GlobalValue::GUID, GlobalValue::GUID>
getGUIDFromValueId(unsigned ValueId);
std::pair<GlobalValue::GUID, CalleeInfo::HotnessType>
readCallGraphEdge(const SmallVector<uint64_t, 64> &Record, unsigned int &I,
bool IsOldProfileFormat, bool HasProfile);
};
} // end anonymous namespace
@@ -4792,6 +4793,33 @@ Error ModuleSummaryIndexBitcodeReader::parseModule(StringRef ModulePath) {
}
}
std::vector<ValueInfo>
ModuleSummaryIndexBitcodeReader::makeRefList(ArrayRef<uint64_t> Record) {
std::vector<ValueInfo> Ret;
Ret.reserve(Record.size());
for (uint64_t RefValueId : Record)
Ret.push_back(getGUIDFromValueId(RefValueId).first);
return Ret;
}
std::vector<FunctionSummary::EdgeTy> ModuleSummaryIndexBitcodeReader::makeCallList(
ArrayRef<uint64_t> Record, bool IsOldProfileFormat, bool HasProfile) {
std::vector<FunctionSummary::EdgeTy> Ret;
Ret.reserve(Record.size());
for (unsigned I = 0, E = Record.size(); I != E; ++I) {
CalleeInfo::HotnessType Hotness = CalleeInfo::HotnessType::Unknown;
GlobalValue::GUID CalleeGUID = getGUIDFromValueId(Record[I]).first;
if (IsOldProfileFormat) {
I += 1; // Skip old callsitecount field
if (HasProfile)
I += 1; // Skip old profilecount field
} else if (HasProfile)
Hotness = static_cast<CalleeInfo::HotnessType>(Record[++I]);
Ret.push_back(FunctionSummary::EdgeTy{CalleeGUID, CalleeInfo{Hotness}});
}
return Ret;
}
// Eagerly parse the entire summary block. This populates the GlobalValueSummary
// objects in the index.
Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
@@ -4868,33 +4896,25 @@ Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
unsigned InstCount = Record[2];
unsigned NumRefs = Record[3];
auto Flags = getDecodedGVSummaryFlags(RawFlags, Version);
std::unique_ptr<FunctionSummary> FS =
llvm::make_unique<FunctionSummary>(Flags, InstCount);
// The module path string ref set in the summary must be owned by the
// index's module string table. Since we don't have a module path
// string table section in the per-module index, we create a single
// module path string table entry with an empty (0) ID to take
// ownership.
FS->setModulePath(TheIndex.addModulePath(ModulePath, 0)->first());
static int RefListStartIndex = 4;
int CallGraphEdgeStartIndex = RefListStartIndex + NumRefs;
assert(Record.size() >= RefListStartIndex + NumRefs &&
"Record size inconsistent with number of references");
for (unsigned I = 4, E = CallGraphEdgeStartIndex; I != E; ++I) {
unsigned RefValueId = Record[I];
GlobalValue::GUID RefGUID = getGUIDFromValueId(RefValueId).first;
FS->addRefEdge(RefGUID);
}
std::vector<ValueInfo> Refs = makeRefList(
ArrayRef<uint64_t>(Record).slice(RefListStartIndex, NumRefs));
bool HasProfile = (BitCode == bitc::FS_PERMODULE_PROFILE);
for (unsigned I = CallGraphEdgeStartIndex, E = Record.size(); I != E;
++I) {
CalleeInfo::HotnessType Hotness;
GlobalValue::GUID CalleeGUID;
std::tie(CalleeGUID, Hotness) =
readCallGraphEdge(Record, I, IsOldProfileFormat, HasProfile);
FS->addCallGraphEdge(CalleeGUID, CalleeInfo(Hotness));
}
std::vector<FunctionSummary::EdgeTy> Calls = makeCallList(
ArrayRef<uint64_t>(Record).slice(CallGraphEdgeStartIndex),
IsOldProfileFormat, HasProfile);
auto FS = llvm::make_unique<FunctionSummary>(
Flags, InstCount, std::move(Refs), std::move(Calls));
auto GUID = getGUIDFromValueId(ValueID);
FS->setModulePath(TheIndex.addModulePath(ModulePath, 0)->first());
FS->setOriginalName(GUID.second);
TheIndex.addGlobalValueSummary(GUID.first, std::move(FS));
break;
@@ -4907,7 +4927,8 @@ Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
uint64_t RawFlags = Record[1];
unsigned AliaseeID = Record[2];
auto Flags = getDecodedGVSummaryFlags(RawFlags, Version);
std::unique_ptr<AliasSummary> AS = llvm::make_unique<AliasSummary>(Flags);
auto AS =
llvm::make_unique<AliasSummary>(Flags, std::vector<ValueInfo>{});
// The module path string ref set in the summary must be owned by the
// index's module string table. Since we don't have a module path
// string table section in the per-module index, we create a single
@@ -4931,14 +4952,10 @@ Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
unsigned ValueID = Record[0];
uint64_t RawFlags = Record[1];
auto Flags = getDecodedGVSummaryFlags(RawFlags, Version);
std::unique_ptr<GlobalVarSummary> FS =
llvm::make_unique<GlobalVarSummary>(Flags);
std::vector<ValueInfo> Refs =
makeRefList(ArrayRef<uint64_t>(Record).slice(2));
auto FS = llvm::make_unique<GlobalVarSummary>(Flags, std::move(Refs));
FS->setModulePath(TheIndex.addModulePath(ModulePath, 0)->first());
for (unsigned I = 2, E = Record.size(); I != E; ++I) {
unsigned RefValueId = Record[I];
GlobalValue::GUID RefGUID = getGUIDFromValueId(RefValueId).first;
FS->addRefEdge(RefGUID);
}
auto GUID = getGUIDFromValueId(ValueID);
FS->setOriginalName(GUID.second);
TheIndex.addGlobalValueSummary(GUID.first, std::move(FS));
@@ -4956,30 +4973,21 @@ Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
unsigned InstCount = Record[3];
unsigned NumRefs = Record[4];
auto Flags = getDecodedGVSummaryFlags(RawFlags, Version);
std::unique_ptr<FunctionSummary> FS =
llvm::make_unique<FunctionSummary>(Flags, InstCount);
LastSeenSummary = FS.get();
FS->setModulePath(ModuleIdMap[ModuleId]);
static int RefListStartIndex = 5;
int CallGraphEdgeStartIndex = RefListStartIndex + NumRefs;
assert(Record.size() >= RefListStartIndex + NumRefs &&
"Record size inconsistent with number of references");
for (unsigned I = RefListStartIndex, E = CallGraphEdgeStartIndex; I != E;
++I) {
unsigned RefValueId = Record[I];
GlobalValue::GUID RefGUID = getGUIDFromValueId(RefValueId).first;
FS->addRefEdge(RefGUID);
}
std::vector<ValueInfo> Refs = makeRefList(
ArrayRef<uint64_t>(Record).slice(RefListStartIndex, NumRefs));
bool HasProfile = (BitCode == bitc::FS_COMBINED_PROFILE);
for (unsigned I = CallGraphEdgeStartIndex, E = Record.size(); I != E;
++I) {
CalleeInfo::HotnessType Hotness;
GlobalValue::GUID CalleeGUID;
std::tie(CalleeGUID, Hotness) =
readCallGraphEdge(Record, I, IsOldProfileFormat, HasProfile);
FS->addCallGraphEdge(CalleeGUID, CalleeInfo(Hotness));
}
std::vector<FunctionSummary::EdgeTy> Edges = makeCallList(
ArrayRef<uint64_t>(Record).slice(CallGraphEdgeStartIndex),
IsOldProfileFormat, HasProfile);
GlobalValue::GUID GUID = getGUIDFromValueId(ValueID).first;
auto FS = llvm::make_unique<FunctionSummary>(
Flags, InstCount, std::move(Refs), std::move(Edges));
LastSeenSummary = FS.get();
FS->setModulePath(ModuleIdMap[ModuleId]);
TheIndex.addGlobalValueSummary(GUID, std::move(FS));
Combined = true;
break;
@@ -4993,7 +5001,7 @@ Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
uint64_t RawFlags = Record[2];
unsigned AliaseeValueId = Record[3];
auto Flags = getDecodedGVSummaryFlags(RawFlags, Version);
std::unique_ptr<AliasSummary> AS = llvm::make_unique<AliasSummary>(Flags);
auto AS = llvm::make_unique<AliasSummary>(Flags, std::vector<ValueInfo>{});
LastSeenSummary = AS.get();
AS->setModulePath(ModuleIdMap[ModuleId]);
@@ -5015,15 +5023,11 @@ Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
uint64_t ModuleId = Record[1];
uint64_t RawFlags = Record[2];
auto Flags = getDecodedGVSummaryFlags(RawFlags, Version);
std::unique_ptr<GlobalVarSummary> FS =
llvm::make_unique<GlobalVarSummary>(Flags);
std::vector<ValueInfo> Refs =
makeRefList(ArrayRef<uint64_t>(Record).slice(3));
auto FS = llvm::make_unique<GlobalVarSummary>(Flags, std::move(Refs));
LastSeenSummary = FS.get();
FS->setModulePath(ModuleIdMap[ModuleId]);
for (unsigned I = 3, E = Record.size(); I != E; ++I) {
unsigned RefValueId = Record[I];
GlobalValue::GUID RefGUID = getGUIDFromValueId(RefValueId).first;
FS->addRefEdge(RefGUID);
}
GlobalValue::GUID GUID = getGUIDFromValueId(ValueID).first;
TheIndex.addGlobalValueSummary(GUID, std::move(FS));
Combined = true;
@@ -5043,23 +5047,6 @@ Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
llvm_unreachable("Exit infinite loop");
}
std::pair<GlobalValue::GUID, CalleeInfo::HotnessType>
ModuleSummaryIndexBitcodeReader::readCallGraphEdge(
const SmallVector<uint64_t, 64> &Record, unsigned int &I,
const bool IsOldProfileFormat, const bool HasProfile) {
auto Hotness = CalleeInfo::HotnessType::Unknown;
unsigned CalleeValueId = Record[I];
GlobalValue::GUID CalleeGUID = getGUIDFromValueId(CalleeValueId).first;
if (IsOldProfileFormat) {
I += 1; // Skip old callsitecount field
if (HasProfile)
I += 1; // Skip old profilecount field
} else if (HasProfile)
Hotness = static_cast<CalleeInfo::HotnessType>(Record[++I]);
return {CalleeGUID, Hotness};
}
// Parse the module string table block into the Index.
// This populates the ModulePathStringTable map in the index.
Error ModuleSummaryIndexBitcodeReader::parseModuleStringTable() {