[PATCH] D112042: [llvm-profgen] Skip duplication factor outside of body sample computation

[Wenlei He via Phabricator via llvm-commits]

wenlei created this revision.
wenlei added reviewers: hoy, wlei.
Herald added subscribers: modimo, lxfind.
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We incorrectly use duplication factor for total samples even though we already accumulate samples instead of taking MAX. It causes profile to have bloated total samples for functions with loop unrolled or vectorized. The change fix the issue for total sample, head sample and call target samples.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D112042

Files:
  llvm/test/tools/llvm-profgen/inline-noprobe2.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
@@ -274,6 +274,12 @@
     uint64_t Count) {
   // Use the maximum count of samples with same line location
   uint32_t Discriminator = getBaseDiscriminator(LeafLoc.Location.Discriminator);
+
+  // Use duplication factor to compensated for loop unroll/vectorization.
+  // Note that this is only needed when we're taking MAX of the counts at
+  // the location instead of SUM.
+  Count *= getDuplicationFactor(LeafLoc.Location.Discriminator);
+
   ErrorOr<uint64_t> R =
       FunctionProfile.findSamplesAt(LeafLoc.Location.LineOffset, Discriminator);
 
@@ -384,12 +390,10 @@
       const SampleContextFrameVector &FrameVec =
           Binary->getFrameLocationStack(Offset);
       if (!FrameVec.empty()) {
-        uint64_t DC = Count * getDuplicationFactor(
-                                  FrameVec.back().Location.Discriminator);
         FunctionSamples &FunctionProfile =
-            getLeafProfileAndAddTotalSamples(FrameVec, DC);
+            getLeafProfileAndAddTotalSamples(FrameVec, Count);
         updateBodySamplesforFunctionProfile(FunctionProfile, FrameVec.back(),
-                                            DC);
+                                            Count);
       }
       // Move to next IP within the range.
       IP.advance();
@@ -430,7 +434,6 @@
     const SampleContextFrameVector &FrameVec =
         Binary->getFrameLocationStack(SourceOffset);
     if (!FrameVec.empty()) {
-      Count *= getDuplicationFactor(FrameVec.back().Location.Discriminator);
       FunctionSamples &FunctionProfile =
           getLeafProfileAndAddTotalSamples(FrameVec, Count);
       FunctionProfile.addCalledTargetSamples(
@@ -545,10 +548,8 @@
       auto LeafLoc = Binary->getInlineLeafFrameLoc(Offset);
       if (LeafLoc.hasValue()) {
         // Recording body sample for this specific context
-        uint64_t DC =
-            Count * getDuplicationFactor(LeafLoc->Location.Discriminator);
-        updateBodySamplesforFunctionProfile(FunctionProfile, *LeafLoc, DC);
-        FunctionProfile.addTotalSamples(DC);
+        updateBodySamplesforFunctionProfile(FunctionProfile, *LeafLoc, Count);
+        FunctionProfile.addTotalSamples(Count);
       }
 
       // Move to next IP within the range
@@ -575,7 +576,6 @@
     auto LeafLoc = Binary->getInlineLeafFrameLoc(SourceOffset);
     if (!LeafLoc.hasValue())
       continue;
-    Count *= getDuplicationFactor(LeafLoc->Location.Discriminator);
     FunctionProfile.addCalledTargetSamples(
         LeafLoc->Location.LineOffset,
         getBaseDiscriminator(LeafLoc->Location.Discriminator), CalleeName,
Index: llvm/test/tools/llvm-profgen/inline-noprobe2.test
===================================================================
--- llvm/test/tools/llvm-profgen/inline-noprobe2.test
+++ llvm/test/tools/llvm-profgen/inline-noprobe2.test
@@ -46,7 +46,7 @@
 ;CHECK-NEXT:   1: 6
 ;CHECK-NEXT:   2: 6
 ;CHECK-NEXT:   3: 6
-;CHECK-NEXT: partition_pivot_last:647:7
+;CHECK-NEXT: partition_pivot_last:389:7
 ;CHECK-NEXT:  1: 6
 ;CHECK-NEXT:  2: 6
 ;CHECK-NEXT:  3: 6
@@ -62,7 +62,7 @@
 
 ;CHECK-NEXT:  6: 5
 ;CHECK-NEXT:  7: 5
-;CHECK-NEXT:  5: swap:116
+;CHECK-NEXT:  5: swap:61
 
 ;w/o duplication factor :  1: 9
 ;w/o duplication factor :  2: 9


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