[nfc][InstrFDO] Add Header::getIndexedProfileVersion and use it to decide profile version. (#93613)

This is a split of #93346 as
discussed.

Author: mingmingl-llvm

llvm/include/llvm/ProfileData/InstrProf.h

@@ -1211,6 +1211,10 @@ struct Header {
   // Returns the size of the header in bytes for all valid fields based on the
   // version. I.e a older version header will return a smaller size.
   size_t size() const;
+
+  // Return the indexed profile version, i.e., the least significant 32 bits
+  // in Header.Version.
+  uint64_t getIndexedProfileVersion() const;
 };
 
 // Profile summary data recorded in the profile data file in indexed

llvm/lib/ProfileData/InstrProf.cpp

@@ -1656,10 +1656,11 @@ Expected<Header> Header::readFromBuffer(const unsigned char *Buffer) {
 
   // Read the version.
   H.Version = read(Buffer, offsetOf(&Header::Version));
-  if (GET_VERSION(H.Version) > IndexedInstrProf::ProfVersion::CurrentVersion)
+  if (H.getIndexedProfileVersion() >
+      IndexedInstrProf::ProfVersion::CurrentVersion)
     return make_error<InstrProfError>(instrprof_error::unsupported_version);
 
-  switch (GET_VERSION(H.Version)) {
+  switch (H.getIndexedProfileVersion()) {
     // When a new field is added in the header add a case statement here to
     // populate it.
     static_assert(
@@ -1689,8 +1690,12 @@ Expected<Header> Header::readFromBuffer(const unsigned char *Buffer) {
   return H;
 }
 
+uint64_t Header::getIndexedProfileVersion() const {
+  return GET_VERSION(Version);
+}
+
 size_t Header::size() const {
-  switch (GET_VERSION(Version)) {
+  switch (getIndexedProfileVersion()) {
     // When a new field is added to the header add a case statement here to
     // compute the size as offset of the new field + size of the new field. This
     // relies on the field being added to the end of the list.

llvm/lib/ProfileData/InstrProfReader.cpp

@@ -1328,15 +1328,15 @@ Error IndexedInstrProfReader::readHeader() {
 
   // The MemProfOffset field in the header is only valid when the format
   // version is higher than 8 (when it was introduced).
-  if (GET_VERSION(Header->Version) >= 8 &&
+  if (Header->getIndexedProfileVersion() >= 8 &&
       Header->Version & VARIANT_MASK_MEMPROF) {
     if (Error E = MemProfReader.deserialize(Start, Header->MemProfOffset))
       return E;
   }
 
   // BinaryIdOffset field in the header is only valid when the format version
   // is higher than 9 (when it was introduced).
-  if (GET_VERSION(Header->Version) >= 9) {
+  if (Header->getIndexedProfileVersion() >= 9) {
     const unsigned char *Ptr = Start + Header->BinaryIdOffset;
     // Read binary ids size.
     BinaryIdsSize =
@@ -1350,7 +1350,7 @@ Error IndexedInstrProfReader::readHeader() {
                                         "corrupted binary ids");
   }
 
-  if (GET_VERSION(Header->Version) >= 12) {
+  if (Header->getIndexedProfileVersion() >= 12) {
     const unsigned char *Ptr = Start + Header->VTableNamesOffset;
 
     CompressedVTableNamesLen =
@@ -1363,7 +1363,7 @@ Error IndexedInstrProfReader::readHeader() {
       return make_error<InstrProfError>(instrprof_error::truncated);
   }
 
-  if (GET_VERSION(Header->Version) >= 10 &&
+  if (Header->getIndexedProfileVersion() >= 10 &&
       Header->Version & VARIANT_MASK_TEMPORAL_PROF) {
     const unsigned char *Ptr = Start + Header->TemporalProfTracesOffset;
     const auto *PtrEnd = (const unsigned char *)DataBuffer->getBufferEnd();