[llvm] [HWASAN][UBSAN] Don't use default `profile-summary-cutoff-hot` (PR #87691)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Vitaly Buka (vitalybuka)

<details>
<summary>Changes</summary>

Default cutoff is not usefull here. Decision to
enable or not sanitizer causes more significant
performance impact, than a typical optimizations
which rely on `profile-summary-cutoff-hot`.


---
Full diff: https://github.com/llvm/llvm-project/pull/87691.diff


4 Files Affected:

- (modified) llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp (+4-10) 
- (modified) llvm/lib/Transforms/Instrumentation/RemoveTrapsPass.cpp (+3-10) 
- (modified) llvm/test/Instrumentation/HWAddressSanitizer/pgo-opt-out.ll (+1-1) 
- (modified) llvm/test/Transforms/RemoveTraps/remove-traps.ll (+1-1) 


``````````diff
diff --git a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
index 88e84ed7be8e6a..8562e2efd33e10 100644
--- a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
@@ -187,10 +187,8 @@ static cl::opt<bool>
                               cl::desc("Use selective instrumentation"),
                               cl::Hidden, cl::init(false));
 
-static cl::opt<int> ClHotPercentileCutoff(
-    "hwasan-percentile-cutoff-hot", cl::init(0),
-    cl::desc("Alternative hot percentile cuttoff."
-             "By default `-profile-summary-cutoff-hot` is used."));
+static cl::opt<int> ClHotPercentileCutoff("hwasan-percentile-cutoff-hot",
+                                          cl::desc("Hot percentile cuttoff."));
 
 static cl::opt<float>
     ClRandomSkipRate("hwasan-random-skip-rate", cl::init(0),
@@ -1512,12 +1510,8 @@ bool HWAddressSanitizer::selectiveInstrumentationShouldSkip(
     ++NumNoProfileSummaryFuncs;
     return false;
   }
-  auto &BFI = FAM.getResult<BlockFrequencyAnalysis>(F);
-  return (
-      (ClHotPercentileCutoff.getNumOccurrences() && ClHotPercentileCutoff >= 0)
-          ? PSI->isFunctionHotInCallGraphNthPercentile(ClHotPercentileCutoff,
-                                                       &F, BFI)
-          : PSI->isFunctionHotInCallGraph(&F, BFI));
+  return PSI->isFunctionHotInCallGraphNthPercentile(
+      ClHotPercentileCutoff, &F, FAM.getResult<BlockFrequencyAnalysis>(F));
 }
 
 void HWAddressSanitizer::sanitizeFunction(Function &F,
diff --git a/llvm/lib/Transforms/Instrumentation/RemoveTrapsPass.cpp b/llvm/lib/Transforms/Instrumentation/RemoveTrapsPass.cpp
index d87f7482a21d25..6bcbccda031cec 100644
--- a/llvm/lib/Transforms/Instrumentation/RemoveTrapsPass.cpp
+++ b/llvm/lib/Transforms/Instrumentation/RemoveTrapsPass.cpp
@@ -22,10 +22,8 @@ using namespace llvm;
 
 #define DEBUG_TYPE "remove-traps"
 
-static cl::opt<int> HotPercentileCutoff(
-    "remove-traps-percentile-cutoff-hot", cl::init(0),
-    cl::desc("Alternative hot percentile cuttoff. By default "
-             "`-profile-summary-cutoff-hot` is used."));
+static cl::opt<int> HotPercentileCutoff("remove-traps-percentile-cutoff-hot",
+                                        cl::desc("Hot percentile cuttoff."));
 
 static cl::opt<float>
     RandomRate("remove-traps-random-rate", cl::init(0.0),
@@ -64,12 +62,7 @@ static bool removeUbsanTraps(Function &F, const BlockFrequencyInfo &BFI,
           uint64_t Count = 0;
           for (const auto *PR : predecessors(&BB))
             Count += BFI.getBlockProfileCount(PR).value_or(0);
-
-          IsHot =
-              HotPercentileCutoff.getNumOccurrences()
-                  ? (HotPercentileCutoff > 0 &&
-                     PSI->isHotCountNthPercentile(HotPercentileCutoff, Count))
-                  : PSI->isHotCount(Count);
+          IsHot = PSI->isHotCountNthPercentile(HotPercentileCutoff, Count);
         }
 
         if (ShouldRemove(IsHot)) {
diff --git a/llvm/test/Instrumentation/HWAddressSanitizer/pgo-opt-out.ll b/llvm/test/Instrumentation/HWAddressSanitizer/pgo-opt-out.ll
index e568f5b88dc145..da9bff8c048cc6 100644
--- a/llvm/test/Instrumentation/HWAddressSanitizer/pgo-opt-out.ll
+++ b/llvm/test/Instrumentation/HWAddressSanitizer/pgo-opt-out.ll
@@ -1,7 +1,7 @@
 ; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-selective-instrumentation=1 \
 ; RUN:    -hwasan-percentile-cutoff-hot=700000 | FileCheck %s --check-prefix=HOT70
 ; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-selective-instrumentation=1 \
-; RUN:                                 | FileCheck %s --check-prefix=HOT99
+; RUN:    -hwasan-percentile-cutoff-hot=990000 | FileCheck %s --check-prefix=HOT99
 ; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-selective-instrumentation=1 \
 ; RUN:    -hwasan-random-skip-rate=0.0 | FileCheck %s --check-prefix=RANDOM0
 ; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-selective-instrumentation=1 \
diff --git a/llvm/test/Transforms/RemoveTraps/remove-traps.ll b/llvm/test/Transforms/RemoveTraps/remove-traps.ll
index e3cca83884a8e1..4853149f955b09 100644
--- a/llvm/test/Transforms/RemoveTraps/remove-traps.ll
+++ b/llvm/test/Transforms/RemoveTraps/remove-traps.ll
@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
 ; RUN: opt < %s -passes='function(remove-traps)' -S | FileCheck %s --check-prefixes=NOPROFILE
 ; RUN: opt < %s -passes='function(remove-traps)' -remove-traps-random-rate=1 -S | FileCheck %s --check-prefixes=ALL
-; RUN: opt < %s -passes='require<profile-summary>,function(remove-traps)' -S | FileCheck %s --check-prefixes=HOT99
+; RUN: opt < %s -passes='require<profile-summary>,function(remove-traps)' -remove-traps-percentile-cutoff-hot=990000 -S | FileCheck %s --check-prefixes=HOT99
 ; RUN: opt < %s -passes='require<profile-summary>,function(remove-traps)' -remove-traps-percentile-cutoff-hot=700000 -S | FileCheck %s --check-prefixes=HOT70
 
 target triple = "x86_64-pc-linux-gnu"

``````````

</details>


https://github.com/llvm/llvm-project/pull/87691