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
@@ -1017,9 +1017,8 @@
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setDoesNotCapture(F, 1);
     return Changed;
-  // TODO: add LibFunc entries for:
-  // case LibFunc_memset_pattern4:
-  // case LibFunc_memset_pattern8:
+  case LibFunc_memset_pattern4:
+  case LibFunc_memset_pattern8:
   case LibFunc_memset_pattern16:
     Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotCapture(F, 0);
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
@@ -1011,8 +1011,13 @@
 declare i64 @write(i32, i8*, i64)
 
 
+; 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]+]]
+declare void @memset_pattern4(i8*, i8*, i64)
+; CHECK-DARWIN: declare void @memset_pattern8(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE]]
+declare void @memset_pattern8(i8*, i8*, i64)
 ; memset_pattern16 isn't available everywhere.
-; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE:#[0-9]+]]
+; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture writeonly, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE]]
 declare void @memset_pattern16(i8*, i8*, i64)