[llvm] bbc629e - [CallPrinter] Fix maxFreq = 0 case

[Kirill Bobyrev via llvm-commits]

Author: Kirill Bobyrev
Date: 2020-06-17T10:44:28+02:00
New Revision: bbc629ebd6429d43cfd72d9a0e2b5ca8a4083b54

URL: https://github.com/llvm/llvm-project/commit/bbc629ebd6429d43cfd72d9a0e2b5ca8a4083b54
DIFF: https://github.com/llvm/llvm-project/commit/bbc629ebd6429d43cfd72d9a0e2b5ca8a4083b54.diff

LOG: [CallPrinter] Fix maxFreq = 0 case

llvm::getHeatColor becomes a problem when maxFreq = 0 -> freq = 0 =>
log2(double(freq)) / log2(maxFreq) -> log2(0.) / log2(0.) which
results in illegal instruction on some architectures.

Problematic revision: https://reviews.llvm.org/D77172

Added: 
    

Modified: 
    llvm/lib/Analysis/HeatUtils.cpp

Removed: 
    


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diff  --git a/llvm/lib/Analysis/HeatUtils.cpp b/llvm/lib/Analysis/HeatUtils.cpp
index 99d39d8bbe9e..15d672ffbf9a 100644
--- a/llvm/lib/Analysis/HeatUtils.cpp
+++ b/llvm/lib/Analysis/HeatUtils.cpp
@@ -62,7 +62,7 @@ uint64_t getMaxFreq(const Function &F, const BlockFrequencyInfo *BFI) {
 std::string getHeatColor(uint64_t freq, uint64_t maxFreq) {
   if (freq > maxFreq)
     freq = maxFreq;
-  double percent = log2(double(freq)) / log2(maxFreq);
+  double percent = (maxFreq > 0) ? log2(double(freq)) / log2(maxFreq) : 0;
   return getHeatColor(percent);
 }