[llvm] 299b5d4 - [CSSPGO] Enable pseudo probe instrumentation in O0 mode.

[Hongtao Yu via llvm-commits]

Author: Hongtao Yu
Date: 2021-09-14T18:13:29-07:00
New Revision: 299b5d420df15fafc9936bc24995f6cd6ad325be

URL: https://github.com/llvm/llvm-project/commit/299b5d420df15fafc9936bc24995f6cd6ad325be
DIFF: https://github.com/llvm/llvm-project/commit/299b5d420df15fafc9936bc24995f6cd6ad325be.diff

LOG: [CSSPGO] Enable pseudo probe instrumentation in O0 mode.

Pseudo probe instrumentation was missing from O0 build. It is needed in cases where some source files are built in O0 while the others are built in optimize mode.

Reviewed By: wenlei, wlei, wmi

Differential Revision: https://reviews.llvm.org/D109531

Added: 
    

Modified: 
    clang/test/CodeGen/pseudo-probe-emit.c
    llvm/lib/Passes/PassBuilder.cpp

Removed: 
    


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diff  --git a/clang/test/CodeGen/pseudo-probe-emit.c b/clang/test/CodeGen/pseudo-probe-emit.c
index 5fe1d23846763..b4e6a014d474b 100644
--- a/clang/test/CodeGen/pseudo-probe-emit.c
+++ b/clang/test/CodeGen/pseudo-probe-emit.c
@@ -1,3 +1,4 @@
+// RUN: %clang_cc1 -O0 -fno-legacy-pass-manager -fpseudo-probe-for-profiling -debug-info-kind=limited -emit-llvm -o - %s | FileCheck %s
 // RUN: %clang_cc1 -O2 -fno-legacy-pass-manager -fpseudo-probe-for-profiling -debug-info-kind=limited -emit-llvm -o - %s | FileCheck %s
 
 // Check the generation of pseudoprobe intrinsic call

diff  --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 6c3241ba3e52c..076ff95cb8d21 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -1924,6 +1924,13 @@ ModulePassManager PassBuilder::buildO0DefaultPipeline(OptimizationLevel Level,
 
   ModulePassManager MPM;
 
+  // Perform pseudo probe instrumentation in O0 mode. This is for the
+  // consistency between 
diff erent build modes. For example, a LTO build can be
+  // mixed with an O0 prelink and an O2 postlink. Loading a sample profile in
+  // the postlink will require pseudo probe instrumentation in the prelink.
+  if (PGOOpt && PGOOpt->PseudoProbeForProfiling)
+    MPM.addPass(SampleProfileProbePass(TM));
+
   if (PGOOpt && (PGOOpt->Action == PGOOptions::IRInstr ||
                  PGOOpt->Action == PGOOptions::IRUse))
     addPGOInstrPassesForO0(