[PATCH] D96811: [CSSPGO][llvm-profgen] Change sample count of dangling probe in llvm-profgen

[Lei Wang via Phabricator via llvm-commits]

wlei updated this revision to Diff 328224.
wlei added a comment.

use merge function to update body samples for probe


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D96811/new/

https://reviews.llvm.org/D96811

Files:
  llvm/include/llvm/ProfileData/SampleProf.h
  llvm/test/tools/llvm-profgen/inline-cs-pseudoprobe.test
  llvm/test/tools/llvm-profgen/noinline-cs-pseudoprobe.test
  llvm/tools/llvm-profgen/ProfileGenerator.cpp


Index: llvm/tools/llvm-profgen/ProfileGenerator.cpp
===================================================================
--- llvm/tools/llvm-profgen/ProfileGenerator.cpp
+++ llvm/tools/llvm-profgen/ProfileGenerator.cpp
@@ -492,7 +492,17 @@
     FunctionSamples &FunctionProfile =
         getFunctionProfileForLeafProbe(ContextStrStack, Probe, Binary);
 
-    FunctionProfile.addBodySamples(Probe->Index, 0, Count);
+    // Use InvalidProbeCount(UINT64_MAX) to mark sample count for a dangling
+    // probe. Dangling probes are the probes associated to an empty block. With
+    // this place holder, sample count on dangling probe will not be trusted by
+    // the compiler and it will rely on the counts inference algorithm to get
+    // the probe a reasonable count.
+    if (Probe->isDangling()) {
+      FunctionProfile.addBodySamplesForProbe(
+          Probe->Index, FunctionSamples::InvalidProbeCount);
+      continue;
+    }
+    FunctionProfile.addBodySamplesForProbe(Probe->Index, Count);
     FunctionProfile.addTotalSamples(Count);
     if (Probe->isEntry()) {
       FunctionProfile.addHeadSamples(Count);
Index: llvm/test/tools/llvm-profgen/noinline-cs-pseudoprobe.test
===================================================================
--- llvm/test/tools/llvm-profgen/noinline-cs-pseudoprobe.test
+++ llvm/test/tools/llvm-profgen/noinline-cs-pseudoprobe.test
@@ -8,10 +8,10 @@
 ; CHECK-NEXT: 6: 15
 ; CHECK-NEXT: 8: 15 bar:15
 ; CHECK-NEXT: !CFGChecksum: 138950591924
-; CHECK-NEXT:[main:2 @ foo:8 @ bar]:60:15
+; CHECK-NEXT:[main:2 @ foo:8 @ bar]:30:15
 ; CHECK-NEXT: 1: 15
-; CHECK-NEXT: 2: 15
-; CHECK-NEXT: 3: 15
+; CHECK-NEXT: 2: 18446744073709551615
+; CHECK-NEXT: 3: 18446744073709551615
 ; CHECK-NEXT: 4: 15
 ; CHECK-NEXT: !CFGChecksum: 72617220756
 
Index: llvm/test/tools/llvm-profgen/inline-cs-pseudoprobe.test
===================================================================
--- llvm/test/tools/llvm-profgen/inline-cs-pseudoprobe.test
+++ llvm/test/tools/llvm-profgen/inline-cs-pseudoprobe.test
@@ -9,10 +9,10 @@
 ; CHECK-NEXT: 6: 15
 ; CHECK-NEXT: 8: 14 bar:14
 ; CHECK-NEXT: !CFGChecksum: 138950591924
-; CHECK-NEXT:[main:2 @ foo:8 @ bar]:56:14
+; CHECK-NEXT:[main:2 @ foo:8 @ bar]:28:14
 ; CHECK-NEXT: 1: 14
-; CHECK-NEXT: 2: 14
-; CHECK-NEXT: 3: 14
+; CHECK-NEXT: 2: 18446744073709551615
+; CHECK-NEXT: 3: 18446744073709551615
 ; CHECK-NEXT: 4: 14
 ; CHECK-NEXT: !CFGChecksum: 72617220756
 
Index: llvm/include/llvm/ProfileData/SampleProf.h
===================================================================
--- llvm/include/llvm/ProfileData/SampleProf.h
+++ llvm/include/llvm/ProfileData/SampleProf.h
@@ -559,6 +559,13 @@
         FName, Num, Weight);
   }
 
+  sampleprof_error addBodySamplesForProbe(uint32_t Index, uint64_t Num,
+                                          uint64_t Weight = 1) {
+    SampleRecord S;
+    S.addSamples(Num, Weight);
+    return BodySamples[LineLocation(Index, 0)].merge(S, Weight);
+  }
+
   /// Return the number of samples collected at the given location.
   /// Each location is specified by \p LineOffset and \p Discriminator.
   /// If the location is not found in profile, return error.


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