vendor/llvm-project/llvmorg-10-init-17466-ge26a78e7085

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
index 55c64fa4b727b..d35abb92dd086 100644
--- a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
@@ -27,7 +27,9 @@
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/MDBuilder.h"
+#include "llvm/InitializePasses.h"
 #include "llvm/Support/BranchProbability.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Transforms/Utils.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
@@ -623,6 +625,10 @@ static bool checkMDProf(MDNode *MD, BranchProbability &TrueProb,
   assert(SumWt >= TrueWt && SumWt >= FalseWt &&
          "Overflow calculating branch probabilities.");
 
+  // Guard against 0-to-0 branch weights to avoid a division-by-zero crash.
+  if (SumWt == 0)
+    return false;
+
   TrueProb = BranchProbability::getBranchProbability(TrueWt, SumWt);
   FalseProb = BranchProbability::getBranchProbability(FalseWt, SumWt);
   return true;
@@ -1061,6 +1067,7 @@ static bool shouldSplit(Instruction *InsertPoint,
                         DenseSet<Value *> &ConditionValues,
                         DominatorTree &DT,
                         DenseSet<Instruction *> &Unhoistables) {
+  assert(InsertPoint && "Null InsertPoint");
   CHR_DEBUG(
       dbgs() << "shouldSplit " << *InsertPoint << " PrevConditionValues ";
       for (Value *V : PrevConditionValues) {
@@ -1071,7 +1078,6 @@ static bool shouldSplit(Instruction *InsertPoint,
         dbgs() << *V << ", ";
       }
       dbgs() << "\n");
-  assert(InsertPoint && "Null InsertPoint");
   // If any of Bases isn't hoistable to the hoist point, split.
   for (Value *V : ConditionValues) {
     DenseMap<Instruction *, bool> Visited;