[llvm] 81c2497 - [llvm-profgen] Use hot threshold for context merging and trimming

[Wenlei He via llvm-commits]

Author: Wenlei He
Date: 2021-09-22T15:01:51-07:00
New Revision: 81c249784f424f8b7bd04dcbeaf0594d9b529696

URL: https://github.com/llvm/llvm-project/commit/81c249784f424f8b7bd04dcbeaf0594d9b529696
DIFF: https://github.com/llvm/llvm-project/commit/81c249784f424f8b7bd04dcbeaf0594d9b529696.diff

LOG: [llvm-profgen] Use hot threshold for context merging and trimming

Without preinliner, we need to tune down the cold count cutoff to merge/trim more context to limit profile size for large components. However it doesn't make sense for cold threshold to be higher than hot threshold, so we now change to use hot threshold as merging/trimming cut off instead.

Differential Revision: https://reviews.llvm.org/D110212

Added: 
    

Modified: 
    llvm/test/tools/llvm-profgen/merge-cold-profile.test
    llvm/tools/llvm-profgen/ProfileGenerator.cpp

Removed: 
    


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diff  --git a/llvm/test/tools/llvm-profgen/merge-cold-profile.test b/llvm/test/tools/llvm-profgen/merge-cold-profile.test
index 538d5568ba0f2..a012ead9ac57b 100644
--- a/llvm/test/tools/llvm-profgen/merge-cold-profile.test
+++ b/llvm/test/tools/llvm-profgen/merge-cold-profile.test
@@ -1,17 +1,17 @@
 ; Used the data from recursion-compression.test, refer it for the unmerged output
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t1 --compress-recursion=-1 --profile-summary-cold-count=8
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t1 --compress-recursion=-1 --profile-summary-hot-count=8
 ; RUN: FileCheck %s --input-file %t1
 
 ; Test --csprof-trim-cold-context=0
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t2 --compress-recursion=-1 --profile-summary-cold-count=100 --csprof-trim-cold-context=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t2 --compress-recursion=-1 --profile-summary-hot-count=100 --csprof-trim-cold-context=0
 ; RUN: FileCheck %s --input-file %t2 --check-prefix=CHECK-KEEP-COLD
 
 ; Test --csprof-merge-cold-context=0
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t3 --compress-recursion=-1 --profile-summary-cold-count=10 --csprof-merge-cold-context=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t3 --compress-recursion=-1 --profile-summary-hot-count=10 --csprof-merge-cold-context=0
 ; RUN: FileCheck %s --input-file %t3 --check-prefix=CHECK-UNMERGED
 
 ; Test --csprof-frame-depth-for-cold-context
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t2 --compress-recursion=-1 --profile-summary-cold-count=100 --csprof-trim-cold-context=0 --csprof-max-cold-context-depth=2
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t2 --compress-recursion=-1 --profile-summary-hot-count=100 --csprof-trim-cold-context=0 --csprof-max-cold-context-depth=2
 ; RUN: FileCheck %s --input-file %t2 --check-prefix=CHECK-COLD-CONTEXT-LENGTH
 
 ; CHECK:     [fa]:14:4

diff  --git a/llvm/tools/llvm-profgen/ProfileGenerator.cpp b/llvm/tools/llvm-profgen/ProfileGenerator.cpp
index 5251e3f187c70..32641328f649b 100644
--- a/llvm/tools/llvm-profgen/ProfileGenerator.cpp
+++ b/llvm/tools/llvm-profgen/ProfileGenerator.cpp
@@ -418,18 +418,12 @@ void CSProfileGenerator::postProcessProfiles() {
       CSProfMergeColdContext.getNumOccurrences()) {
     SampleContextTrimmer(ProfileMap)
         .trimAndMergeColdContextProfiles(
-            ColdCountThreshold, CSProfTrimColdContext, CSProfMergeColdContext,
+            HotCountThreshold, CSProfTrimColdContext, CSProfMergeColdContext,
             CSProfMaxColdContextDepth);
   }
 }
 
 void CSProfileGenerator::computeSummaryAndThreshold() {
-  // Update the default value of cold cutoff for llvm-profgen.
-  // Do it here because we don't want to change the global default,
-  // which would lead CS profile size too large.
-  if (!ProfileSummaryCutoffCold.getNumOccurrences())
-    ProfileSummaryCutoffCold = 999000;
-
   SampleProfileSummaryBuilder Builder(ProfileSummaryBuilder::DefaultCutoffs);
   auto Summary = Builder.computeSummaryForProfiles(ProfileMap);
   HotCountThreshold = ProfileSummaryBuilder::getHotCountThreshold(