Clang change: Do not inline hot callsites for samplepgo in thinlto compile phase.
Summary:
Because SamplePGO passes will be invoked twice in ThinLTO build: once at compile phase, the other at backend. We want to make sure the IR at the 2nd phase matches the hot part in pro
file, thus we do not want to inline hot callsites in the first phase.
Reviewers: tejohnson, eraman
Reviewed By: tejohnson
Subscribers: mehdi_amini, cfe-commits, Prazek
Differential Revision: https://reviews.llvm.org/D31202
llvm-svn: 298429
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 73730e0..d1aae08 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -318,8 +318,13 @@
!CodeGenOpts.DisableLifetimeMarkers);
PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
} else {
+ // We do not want to inline hot callsites for SamplePGO module-summary build
+ // because profile annotation will happen again in ThinLTO backend, and we
+ // want the IR of the hot path to match the profile.
PMBuilder.Inliner = createFunctionInliningPass(
- CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize);
+ CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
+ (!CodeGenOpts.SampleProfileFile.empty() &&
+ CodeGenOpts.EmitSummaryIndex));
}
PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;