[PGO] Differentiate Clang instrumentation and IR level instrumentation profiles

This patch uses one bit in profile version to differentiate Clang
instrumentation and IR level instrumentation profiles.

PGOInstrumenation generates a COMDAT variable __llvm_profile_raw_version so
that the compiler runtime can set the right profile kind.
PGOInstrumenation now checks this bit to make sure it's an IR level
instrumentation profile.

Differential Revision: http://reviews.llvm.org/D15540

llvm-svn: 260146

1 files changed, 5 insertions, 1 deletions

diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
index a486d4e..3e32571 100644
--- a/llvm/lib/ProfileData/InstrProfWriter.cpp
+++ b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -142,7 +142,7 @@ public:
 }
 
 InstrProfWriter::InstrProfWriter(bool Sparse)
-    : Sparse(Sparse), FunctionData(),
+    : Sparse(Sparse), FunctionData(), ProfileKind(PF_Unknown),
       InfoObj(new InstrProfRecordWriterTrait()) {}
 
 InstrProfWriter::~InstrProfWriter() { delete InfoObj; }
@@ -230,6 +230,8 @@ void InstrProfWriter::writeImpl(ProfOStream &OS) {
   IndexedInstrProf::Header Header;
   Header.Magic = IndexedInstrProf::Magic;
   Header.Version = IndexedInstrProf::ProfVersion::CurrentVersion;
+  if (ProfileKind == PF_IRLevel)
+    Header.Version |= VARIANT_MASK_IR_PROF;
   Header.Unused = 0;
   Header.HashType = static_cast<uint64_t>(IndexedInstrProf::HashType);
   Header.HashOffset = 0;
@@ -336,6 +338,8 @@ void InstrProfWriter::writeRecordInText(const InstrProfRecord &Func,
 }
 
 void InstrProfWriter::writeText(raw_fd_ostream &OS) {
+  if (ProfileKind == PF_IRLevel)
+    OS << "# IR level Instrumentation Flag\n:ir\n";
   InstrProfSymtab Symtab;
   for (const auto &I : FunctionData)
     if (shouldEncodeData(I.getValue()))