[PATCH] D113785: [llvm-profgen] Trim cold function profiles for non-CS mode

[Lei Wang via Phabricator via llvm-commits]

wlei created this revision.
Herald added subscribers: hoy, wenlei, lxfind.
wlei requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D113785

Files:
  llvm/test/tools/llvm-profgen/inline-noprobe2.test
  llvm/tools/llvm-profgen/ProfileGenerator.cpp
  llvm/tools/llvm-profgen/ProfileGenerator.h


Index: llvm/tools/llvm-profgen/ProfileGenerator.h
===================================================================
--- llvm/tools/llvm-profgen/ProfileGenerator.h
+++ llvm/tools/llvm-profgen/ProfileGenerator.h
@@ -122,6 +122,8 @@
   void
   populateBoundarySamplesForAllFunctions(const BranchSample &BranchCounters);
   void postProcessProfiles();
+  void trimColdProfiles(const SampleProfileMap &Profiles,
+                        uint64_t ColdCntThreshold);
   void calculateAndShowDensity(const SampleProfileMap &Profiles) override;
 };
 
Index: llvm/tools/llvm-profgen/ProfileGenerator.cpp
===================================================================
--- llvm/tools/llvm-profgen/ProfileGenerator.cpp
+++ llvm/tools/llvm-profgen/ProfileGenerator.cpp
@@ -49,6 +49,11 @@
     cl::Hidden,
     cl::location(llvm::sampleprof::CSProfileGenerator::MaxCompressionSize));
 
+static cl::opt<bool>
+    TrimColdProfile("trim-cold-profile", cl::init(false), cl::ZeroOrMore,
+                    cl::desc("If the total count of the profile is smaller "
+                             "than threshold, it will be trimmed."));
+
 static cl::opt<bool> CSProfMergeColdContext(
     "csprof-merge-cold-context", cl::init(true), cl::ZeroOrMore,
     cl::desc("If the total count of context profile is smaller than "
@@ -371,9 +376,27 @@
 
 void ProfileGenerator::postProcessProfiles() {
   computeSummaryAndThreshold();
+  trimColdProfiles(ProfileMap, ColdCountThreshold);
   calculateAndShowDensity(ProfileMap);
 }
 
+void ProfileGenerator::trimColdProfiles(const SampleProfileMap &Profiles,
+                                        uint64_t ColdCntThreshold) {
+  if (!TrimColdProfile)
+    return;
+
+  // Move cold profiles into a tmp container.
+  std::vector<SampleContext> ColdProfiles;
+  for (const auto &I : ProfileMap) {
+    if (I.second.getTotalSamples() < ColdCntThreshold)
+      ColdProfiles.emplace_back(I.first);
+  }
+
+  // Remove the cold profile from ProfileMap.
+  for (const auto &I : ColdProfiles)
+    ProfileMap.erase(I);
+}
+
 void ProfileGenerator::generateLineNumBasedProfile() {
   assert(SampleCounters.size() == 1 &&
          "Must have one entry for profile generation.");
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
@@ -6,6 +6,9 @@
 ; RUN: FileCheck %s --input-file %t1 --check-prefix=CHECK
 ; RUN: FileCheck %s --input-file %t2 --check-prefix=CHECK-DENSITY
 
+; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%S/Inputs/inline-noprobe2.perfbin --output=%t1 --use-offset=0 --trim-cold-profile --profile-summary-cold-count=100
+; RUN: FileCheck %s --input-file %t1 --check-prefix=CHECK-TRIM-COLD
+
 ; RUN: llvm-profgen --format=extbinary --perfscript=%S/Inputs/inline-noprobe2.perfscript --binary=%S/Inputs/inline-noprobe2.perfbin --output=%t --populate-profile-symbol-list=1
 ; RUN: llvm-profdata show -show-prof-sym-list -sample %t | FileCheck %s --check-prefix=CHECK-SYM-LIST
 
@@ -102,6 +105,11 @@
 ;CHECK-DENSITY: AutoFDO is estimated to optimize better with 4.9x more samples. Please consider increasing sampling rate or profiling for longer duration to get more samples.
 ;CHECK-DENSITY: Minimum profile density for hot functions with top 99.00% total samples: 0.2
 
+;CHECK-TRIM-COLD: partition_pivot_first:367:5
+;CHECK-TRIM-COLD: partition_pivot_last:225:7
+;CHECK-TRIM-COLD-NOT: quick_sort:83:25
+;CHECK-TRIM-COLD-NOT: main:52:0
+
 ; original code:
 ; clang -O3 -g -fno-optimize-sibling-calls -fdebug-info-for-profiling qsort.c -o a.out
 #include <stdio.h>


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