diff --git a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
--- a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -245,6 +245,10 @@
                                        FunctionAnalysisManager &AM) {
   auto &TTI = AM.getResult<TargetIRAnalysis>(F);
   Options.AC = &AM.getResult<AssumptionAnalysis>(F);
+  if (F.hasFnAttribute(Attribute::OptForFuzzing))
+    Options.setSimplifyCondBranch(false).setFoldTwoEntryPHINode(false);
+  else
+    Options.setSimplifyCondBranch(true).setFoldTwoEntryPHINode(true);
   if (!simplifyFunctionCFG(F, TTI, Options))
     return PreservedAnalyses::all();
   PreservedAnalyses PA;