diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index e8ce3f927493..71316ce8f758 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -306,12 +306,21 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
   case LibFunc_memcpy:
     Changed |= setDoesNotAlias(F, 0);
     Changed |= setDoesNotAlias(F, 1);
-    LLVM_FALLTHROUGH;
+    Changed |= setReturnedArg(F, 0);
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
   case LibFunc_memmove:
     Changed |= setReturnedArg(F, 0);
-    LLVM_FALLTHROUGH;
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
   case LibFunc_mempcpy:
   case LibFunc_memccpy:
+    Changed |= setDoesNotAlias(F, 0);
+    Changed |= setDoesNotAlias(F, 1);
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
index f3b0cd436404..8054802ff021 100644
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -619,7 +619,7 @@ declare i8* @malloc(i64)
 ; CHECK-LINUX: declare noalias i8* @memalign(i64, i64) [[G0]]
 declare i8* @memalign(i64, i64)
 
-; CHECK: declare i8* @memccpy(i8*, i8* nocapture readonly, i32, i64) [[G1]]
+; CHECK: declare i8* @memccpy(i8* noalias, i8* noalias nocapture readonly, i32, i64) [[G1]]
 declare i8* @memccpy(i8*, i8*, i32, i64)
 
 ; CHECK: declare i8* @memchr(i8*, i32, i64) [[G2]]
@@ -631,7 +631,7 @@ declare i32 @memcmp(i8*, i8*, i64)
 ; CHECK: declare i8* @memcpy(i8* noalias returned, i8* noalias nocapture readonly, i64) [[G1]]
 declare i8* @memcpy(i8*, i8*, i64)
 
-; CHECK: declare i8* @mempcpy(i8*, i8* nocapture readonly, i64) [[G1]]
+; CHECK: declare i8* @mempcpy(i8* noalias, i8* noalias nocapture readonly, i64) [[G1]]
 declare i8* @mempcpy(i8*, i8*, i64)
 
 ; CHECK: declare i8* @memmove(i8* returned, i8* nocapture readonly, i64) [[G1]]