[PGO] Add support for reading multiple versions of indexed profile format profile data

Profile readers using incompatible on-disk hash table format can now share the same 
implementation and interfaces. 

Differential Revision: http://reviews.llvm.org/D15100


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254458 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 27 insertions, 22 deletions

diff --git a/lib/ProfileData/InstrProfReader.cpp b/lib/ProfileData/InstrProfReader.cpp
index e4348b19ac0..cfc96873980 100644
--- a/lib/ProfileData/InstrProfReader.cpp
+++ b/lib/ProfileData/InstrProfReader.cpp
@@ -441,11 +441,11 @@ data_type InstrProfLookupTrait::ReadData(StringRef K, const unsigned char *D,
   return DataBuffer;
 }
 
-std::error_code
-InstrProfReaderIndex::getRecords(StringRef FuncName,
-                                 ArrayRef<InstrProfRecord> &Data) {
-  auto Iter = Index->find(FuncName);
-  if (Iter == Index->end())
+template <typename HashTableImpl>
+std::error_code InstrProfReaderIndex<HashTableImpl>::getRecords(
+    StringRef FuncName, ArrayRef<InstrProfRecord> &Data) {
+  auto Iter = HashTable->find(FuncName);
+  if (Iter == HashTable->end())
     return instrprof_error::unknown_function;
 
   Data = (*Iter);
@@ -455,9 +455,11 @@ InstrProfReaderIndex::getRecords(StringRef FuncName,
   return instrprof_error::success;
 }
 
-std::error_code InstrProfReaderIndex::getRecords(
+template <typename HashTableImpl>
+std::error_code InstrProfReaderIndex<HashTableImpl>::getRecords(
     ArrayRef<InstrProfRecord> &Data) {
-  if (atEnd()) return instrprof_error::eof;
+  if (atEnd())
+    return instrprof_error::eof;
 
   Data = *RecordIterator;
 
@@ -466,25 +468,26 @@ std::error_code InstrProfReaderIndex::getRecords(
   return instrprof_error::success;
 }
 
-void InstrProfReaderIndex::Init(const unsigned char *Buckets,
-                                const unsigned char *const Payload,
-                                const unsigned char *const Base,
-                                IndexedInstrProf::HashT HashType,
-                                uint64_t Version) {
+template <typename HashTableImpl>
+InstrProfReaderIndex<HashTableImpl>::InstrProfReaderIndex(
+    const unsigned char *Buckets, const unsigned char *const Payload,
+    const unsigned char *const Base, IndexedInstrProf::HashT HashType,
+    uint64_t Version) {
   FormatVersion = Version;
-  Index.reset(IndexType::Create(Buckets, Payload, Base,
-                                InstrProfLookupTrait(HashType, Version)));
+  HashTable.reset(HashTableImpl::Create(
+      Buckets, Payload, Base,
+      typename HashTableImpl::InfoType(HashType, Version)));
   // Form the map of hash values to const char* keys in profiling data.
   std::vector<std::pair<uint64_t, const char *>> HashKeys;
-  for (auto Key : Index->keys()) {
+  for (auto Key : HashTable->keys()) {
     const char *KeyTableRef = StringTable.insertString(Key);
     HashKeys.push_back(std::make_pair(ComputeHash(HashType, Key), KeyTableRef));
   }
   std::sort(HashKeys.begin(), HashKeys.end(), less_first());
   HashKeys.erase(std::unique(HashKeys.begin(), HashKeys.end()), HashKeys.end());
   // Set the hash key map for the InstrLookupTrait
-  Index->getInfoObj().setHashKeys(std::move(HashKeys));
-  RecordIterator = Index->data_begin();
+  HashTable->getInfoObj().setHashKeys(std::move(HashKeys));
+  RecordIterator = HashTable->data_begin();
 }
 
 bool IndexedInstrProfReader::hasFormat(const MemoryBuffer &DataBuffer) {
@@ -532,8 +535,10 @@ std::error_code IndexedInstrProfReader::readHeader() {
   uint64_t HashOffset = endian::byte_swap<uint64_t, little>(Header->HashOffset);
 
   // The rest of the file is an on disk hash table.
-  Index.Init(Start + HashOffset, Cur, Start, HashType, FormatVersion);
-
+  InstrProfReaderIndexBase *IndexPtr = nullptr;
+  IndexPtr = new InstrProfReaderIndex<OnDiskHashTableImplV3>(
+      Start + HashOffset, Cur, Start, HashType, FormatVersion);
+  Index.reset(IndexPtr);
   return success();
 }
 
@@ -541,7 +546,7 @@ ErrorOr<InstrProfRecord>
 IndexedInstrProfReader::getInstrProfRecord(StringRef FuncName,
                                            uint64_t FuncHash) {
   ArrayRef<InstrProfRecord> Data;
-  std::error_code EC = Index.getRecords(FuncName, Data);
+  std::error_code EC = Index->getRecords(FuncName, Data);
   if (EC != instrprof_error::success)
     return EC;
   // Found it. Look for counters with the right hash.
@@ -571,13 +576,13 @@ std::error_code IndexedInstrProfReader::readNextRecord(
 
   ArrayRef<InstrProfRecord> Data;
 
-  std::error_code EC = Index.getRecords(Data);
+  std::error_code EC = Index->getRecords(Data);
   if (EC != instrprof_error::success)
     return error(EC);
 
   Record = Data[RecordIndex++];
   if (RecordIndex >= Data.size()) {
-    Index.advanceToNextKey();
+    Index->advanceToNextKey();
     RecordIndex = 0;
   }
   return success();