diff --git a/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp b/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
--- a/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
@@ -1373,12 +1373,16 @@
 
   BasicBlock *Entry = BasicBlock::Create(*Ctx, "entry", ResetF);
   IRBuilder<> Builder(Entry);
+  LLVMContext &C = Entry->getContext();
 
   // Zero out the counters.
   for (const auto &I : CountersBySP) {
     GlobalVariable *GV = I.first;
-    Constant *Null = Constant::getNullValue(GV->getValueType());
-    Builder.CreateStore(Null, GV);
+    auto *GVTy = cast<ArrayType>(GV->getValueType());
+    Builder.CreateMemSet(GV, Constant::getNullValue(Type::getInt8Ty(C)),
+                         GVTy->getNumElements() *
+                             GVTy->getPrimitiveSizeInBits(),
+                         GV->getAlign());
   }
 
   Type *RetTy = ResetF->getReturnType();
diff --git a/llvm/test/Transforms/GCOVProfiling/module-flags.ll b/llvm/test/Transforms/GCOVProfiling/module-flags.ll
--- a/llvm/test/Transforms/GCOVProfiling/module-flags.ll
+++ b/llvm/test/Transforms/GCOVProfiling/module-flags.ll
@@ -30,5 +30,7 @@
 ;; Infer uwtable and "frame-pointer" from the module flags.
 ; CHECK: define internal void @__llvm_gcov_writeout() unnamed_addr #[[#ATTR:]]
 ; CHECK: define internal void @__llvm_gcov_reset() unnamed_addr #[[#ATTR]]
+; CHECK-NEXT: entry:
+; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* bitcast ([1 x i64]* @__llvm_gcov_ctr to i8*), i8 0, i64 0, i1 false)
 ; CHECK: define internal void @__llvm_gcov_init() unnamed_addr #[[#ATTR]]
 ; CHECK: attributes #[[#ATTR]] = { noinline nounwind uwtable "frame-pointer"="all" }