diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -1020,12 +1020,10 @@
   case LibFunc_memset_pattern4:
   case LibFunc_memset_pattern8:
   case LibFunc_memset_pattern16:
-    Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotCapture(F, 0);
-    Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
-    return Changed;
+    LLVM_FALLTHROUGH;
   case LibFunc_memset:
     Changed |= setWillReturn(F);
     LLVM_FALLTHROUGH;
diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -1012,11 +1012,11 @@
 
 
 ; memset_pattern{4,8,16} isn't available everywhere.
-; CHECK-DARWIN: declare void @memset_pattern4(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE:#[0-9]+]]
+; CHECK-DARWIN: declare void @memset_pattern4(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare void @memset_pattern4(i8*, i8*, i64)
-; CHECK-DARWIN: declare void @memset_pattern8(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE]]
+; CHECK-DARWIN: declare void @memset_pattern8(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare void @memset_pattern8(i8*, i8*, i64)
-; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE]]
+; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare void @memset_pattern16(i8*, i8*, i64)
 
 
@@ -1034,5 +1034,4 @@
 ; CHECK-DAG: attributes [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN]]  = { inaccessiblemem_or_argmemonly mustprogress nofree nounwind willreturn }
 ; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND]] = { argmemonly nofree nounwind }
 
-; CHECK-DARWIN-DAG: attributes [[ARGMEMONLY_NOFREE]] = { argmemonly nofree }
 ; CHECK-NVPTX-DAG: attributes [[NOFREE_NOUNWIND_READNONE]] = { nofree nosync nounwind readnone }