Refine the PGOOpt and SamplePGOSupport handling.

Summary:
Now that SamplePGOSupport is part of PGOOpt, there are several places that need tweaking:
1. AddDiscriminator pass should *not* be invoked at ThinLTOBackend (as it's already invoked in the PreLink phase)
2. addPGOInstrPasses should only be invoked when either ProfileGenFile or ProfileUseFile is non-empty.
3. SampleProfileLoaderPass should only be invoked when SampleProfileFile is non-empty.
4. PGOIndirectCallPromotion should only be invoked in ProfileUse phase, or in ThinLTOBackend of SamplePGO.

Reviewers: chandlerc, tejohnson, davidxl

Reviewed By: chandlerc

Subscribers: sanjoy, mehdi_amini, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D36040

llvm-svn: 309478

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/include/llvm/Passes/PassBuilder.h b/llvm/include/llvm/Passes/PassBuilder.h
index 5756f49752b..0502913e7fb 100644
--- a/llvm/include/llvm/Passes/PassBuilder.h
+++ b/llvm/include/llvm/Passes/PassBuilder.h
@@ -34,7 +34,12 @@ struct PGOOptions {
              bool SamplePGOSupport = false)
       : ProfileGenFile(ProfileGenFile), ProfileUseFile(ProfileUseFile),
         SampleProfileFile(SampleProfileFile), RunProfileGen(RunProfileGen),
-        SamplePGOSupport(SamplePGOSupport || !SampleProfileFile.empty()) {}
+        SamplePGOSupport(SamplePGOSupport || !SampleProfileFile.empty()) {
+    assert((RunProfileGen ||
+            !SampleProfileFile.empty() ||
+            !ProfileUseFile.empty() ||
+            SamplePGOSupport) && "Illegal PGOOptions.");
+  }
   std::string ProfileGenFile;
   std::string ProfileUseFile;
   std::string SampleProfileFile;