Index: lib/Transforms/Instrumentation/SanitizerCoverage.cpp
===================================================================
--- lib/Transforms/Instrumentation/SanitizerCoverage.cpp
+++ lib/Transforms/Instrumentation/SanitizerCoverage.cpp
@@ -520,7 +520,7 @@
   ArrayType *ArrayOfInt32Ty = ArrayType::get(Int32Ty, NumGuards);
   FunctionGuardArray = new GlobalVariable(
       *CurModule, ArrayOfInt32Ty, false, GlobalVariable::PrivateLinkage,
-      Constant::getNullValue(ArrayOfInt32Ty), "__sancov_gen_");
+      Constant::getAllOnesValue(ArrayOfInt32Ty), "__sancov_gen_");
   if (auto Comdat = F.getComdat())
     FunctionGuardArray->setComdat(Comdat);
   FunctionGuardArray->setSection(getSanCovTracePCGuardSection());