diff --git a/llvm/include/llvm/ProfileData/SampleProfReader.h b/llvm/include/llvm/ProfileData/SampleProfReader.h
--- a/llvm/include/llvm/ProfileData/SampleProfReader.h
+++ b/llvm/include/llvm/ProfileData/SampleProfReader.h
@@ -636,9 +636,6 @@
/// Read the string index and check whether it overflows the table.
template <typename T> inline ErrorOr<size_t> readStringIndex(T &Table);
- /// Return true if we've reached the end of file.
- bool at_eof() const { return Data >= End; }
-
/// Read the next function profile instance.
std::error_code readFuncProfile(const uint8_t *Start);
@@ -756,15 +753,20 @@
// placeholder for subclasses to dispatch their own section readers.
virtual std::error_code readCustomSection(const SecHdrTableEntry &Entry) = 0;
+ /// Determine which container readFuncOffsetTable() should populate, the list
+ /// FuncOffsetList or the map FuncOffsetTable.
+ bool useFuncOffsetList() const;
+
std::unique_ptr<ProfileSymbolList> ProfSymList;
/// The table mapping from function context to the offset of its
/// FunctionSample towards file start.
+ /// At most one of FuncOffsetTable and FuncOffsetList is populated.
DenseMap<SampleContext, uint64_t> FuncOffsetTable;
- /// Function offset mapping ordered by contexts.
- std::unique_ptr<std::vector<std::pair<SampleContext, uint64_t>>>
- OrderedFuncOffsets;
+ /// The list version of FuncOffsetTable. This is used if every entry is
+ /// being accessed.
+ std::vector<std::pair<SampleContext, uint64_t>> FuncOffsetList;
/// The set containing the functions to use when compiling a module.
DenseSet<StringRef> FuncsToUse;
@@ -773,8 +775,6 @@
/// SecFlagFlat flag.
bool SkipFlatProf = false;
- bool FuncOffsetsOrdered = false;
-
public:
SampleProfileReaderExtBinaryBase(std::unique_ptr<MemoryBuffer> B,
LLVMContext &C, SampleProfileFormat Format)
diff --git a/llvm/lib/ProfileData/SampleProfReader.cpp b/llvm/lib/ProfileData/SampleProfReader.cpp
--- a/llvm/lib/ProfileData/SampleProfReader.cpp
+++ b/llvm/lib/ProfileData/SampleProfReader.cpp
@@ -679,7 +679,7 @@
std::error_code SampleProfileReaderBinary::readImpl() {
ProfileIsFS = ProfileIsFSDisciminator;
FunctionSamples::ProfileIsFS = ProfileIsFS;
- while (!at_eof()) {
+ while (Data < End) {
if (std::error_code EC = readFuncProfile(Data))
return EC;
}
@@ -727,9 +727,17 @@
return EC;
break;
case SecFuncOffsetTable:
- FuncOffsetsOrdered = hasSecFlag(Entry, SecFuncOffsetFlags::SecFlagOrdered);
- if (std::error_code EC = readFuncOffsetTable())
- return EC;
+ // If module is absent, we are using LLVM tools, and need to read all
+ // profiles, so skip reading the function offset table.
+ if (!M) {
+ Data = End;
+ } else {
+ assert((!ProfileIsCS ||
+ hasSecFlag(Entry, SecFuncOffsetFlags::SecFlagOrdered)) &&
+ "func offset table should always be sorted in CS profile");
+ if (std::error_code EC = readFuncOffsetTable())
+ return EC;
+ }
break;
case SecFuncMetadata: {
ProfileIsProbeBased =
@@ -753,6 +761,36 @@
return sampleprof_error::success;
}
+bool SampleProfileReaderExtBinaryBase::useFuncOffsetList() const {
+ // If profile is CS, the function offset section is expected to consist of
+ // sequences of contexts in pre-order layout
+ // (e.g. [A, A:1 @ B, A:1 @ B:2.3 @ C] [D, D:1 @ E]), so that when a matched
+ // context in the module is found, the profiles of all its prefix contexts (
+ // all callers on the call stack) are loaded. A list is needed since the order
+ // of profiles matters.
+ if (ProfileIsCS)
+ return true;
+
+ // If the profile is MD5, use the map container to lookup functions in
+ // the module. A remapper has no use on MD5 names.
+ if (useMD5())
+ return false;
+
+ // Profile is not MD5 and if a remapper is present, the remapped name of
+ // every function needed to be matched against the module, so use the list
+ // container since each entry is accessed.
+ if (Remapper)
+ return true;
+
+ // Otherwise use the map container for faster lookup.
+ // TODO: If the cardinality of the function offset section is much smaller
+ // than the number of functions in the module, using the list container can
+ // be always faster, but we need to figure out the constant factor to
+ // determine the cutoff.
+ return false;
+}
+
+
bool SampleProfileReaderExtBinaryBase::collectFuncsFromModule() {
if (!M)
return false;
@@ -763,22 +801,20 @@
}
std::error_code SampleProfileReaderExtBinaryBase::readFuncOffsetTable() {
- // If there are more than one FuncOffsetTable, the profile read associated
- // with previous FuncOffsetTable has to be done before next FuncOffsetTable
- // is read.
+ // If there are more than one function offset section, the profile associated
+ // with the previous section has to be done reading before next one is read.
FuncOffsetTable.clear();
+ FuncOffsetList.clear();
auto Size = readNumber<uint64_t>();
if (std::error_code EC = Size.getError())
return EC;
- FuncOffsetTable.reserve(*Size);
-
- if (FuncOffsetsOrdered) {
- OrderedFuncOffsets =
- std::make_unique<std::vector<std::pair<SampleContext, uint64_t>>>();
- OrderedFuncOffsets->reserve(*Size);
- }
+ bool UseFuncOffsetList = useFuncOffsetList();
+ if (UseFuncOffsetList)
+ FuncOffsetList.reserve(*Size);
+ else
+ FuncOffsetTable.reserve(*Size);
for (uint64_t I = 0; I < *Size; ++I) {
auto FContext(readSampleContextFromTable());
@@ -789,12 +825,13 @@
if (std::error_code EC = Offset.getError())
return EC;
- FuncOffsetTable[*FContext] = *Offset;
- if (FuncOffsetsOrdered)
- OrderedFuncOffsets->emplace_back(*FContext, *Offset);
- }
+ if (UseFuncOffsetList)
+ FuncOffsetList.emplace_back(*FContext, *Offset);
+ else
+ FuncOffsetTable[*FContext] = *Offset;
+ }
- return sampleprof_error::success;
+ return sampleprof_error::success;
}
std::error_code SampleProfileReaderExtBinaryBase::readFuncProfiles() {
@@ -806,7 +843,8 @@
// NameTable section is read.
bool LoadFuncsToBeUsed = collectFuncsFromModule();
- // When LoadFuncsToBeUsed is false, load all the function profiles.
+ // When LoadFuncsToBeUsed is false, we are using LLVM tool, need to read all
+ // profiles.
const uint8_t *Start = Data;
if (!LoadFuncsToBeUsed) {
while (Data < End) {
@@ -836,10 +874,8 @@
// as if they were walked in preorder of a context trie. While
// traversing the trie, a link to the highest common ancestor node is
// kept so that all of its decendants will be loaded.
- assert(OrderedFuncOffsets.get() &&
- "func offset table should always be sorted in CS profile");
const SampleContext *CommonContext = nullptr;
- for (const auto &NameOffset : *OrderedFuncOffsets) {
+ for (const auto &NameOffset : FuncOffsetList) {
const auto &FContext = NameOffset.first;
auto FName = FContext.getName();
// For function in the current module, keep its farthest ancestor
@@ -857,35 +893,38 @@
// Load profile for the current context which originated from
// the common ancestor.
const uint8_t *FuncProfileAddr = Start + NameOffset.second;
- assert(FuncProfileAddr < End && "out of LBRProfile section");
if (std::error_code EC = readFuncProfile(FuncProfileAddr))
return EC;
}
}
+ } else if (useMD5()) {
+ for (auto Name : FuncsToUse) {
+ auto GUID = std::to_string(MD5Hash(Name));
+ auto iter = FuncOffsetTable.find(StringRef(GUID));
+ if (iter == FuncOffsetTable.end())
+ continue;
+ const uint8_t *FuncProfileAddr = Start + iter->second;
+ if (std::error_code EC = readFuncProfile(FuncProfileAddr))
+ return EC;
+ }
+ } else if (Remapper) {
+ for (auto NameOffset : FuncOffsetList) {
+ SampleContext FContext(NameOffset.first);
+ auto FuncName = FContext.getName();
+ if (!FuncsToUse.count(FuncName) && !Remapper->exist(FuncName))
+ continue;
+ const uint8_t *FuncProfileAddr = Start + NameOffset.second;
+ if (std::error_code EC = readFuncProfile(FuncProfileAddr))
+ return EC;
+ }
} else {
- if (useMD5()) {
- for (auto Name : FuncsToUse) {
- auto GUID = std::to_string(MD5Hash(Name));
- auto iter = FuncOffsetTable.find(StringRef(GUID));
- if (iter == FuncOffsetTable.end())
- continue;
- const uint8_t *FuncProfileAddr = Start + iter->second;
- assert(FuncProfileAddr < End && "out of LBRProfile section");
- if (std::error_code EC = readFuncProfile(FuncProfileAddr))
- return EC;
- }
- } else {
- for (auto NameOffset : FuncOffsetTable) {
- SampleContext FContext(NameOffset.first);
- auto FuncName = FContext.getName();
- if (!FuncsToUse.count(FuncName) &&
- (!Remapper || !Remapper->exist(FuncName)))
- continue;
- const uint8_t *FuncProfileAddr = Start + NameOffset.second;
- assert(FuncProfileAddr < End && "out of LBRProfile section");
- if (std::error_code EC = readFuncProfile(FuncProfileAddr))
- return EC;
- }
+ for (auto Name : FuncsToUse) {
+ auto iter = FuncOffsetTable.find(Name);
+ if (iter == FuncOffsetTable.end())
+ continue;
+ const uint8_t *FuncProfileAddr = Start + iter->second;
+ if (std::error_code EC = readFuncProfile(FuncProfileAddr))
+ return EC;
}
}
Data = End;