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
@@ -186,6 +186,7 @@
     return Changed;
   case LibFunc_strchr:
   case LibFunc_strrchr:
+    Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setOnlyReadsMemory(F);
     Changed |= setDoesNotThrow(F);
     return Changed;
@@ -225,9 +226,17 @@
   case LibFunc_strspn:      // 0,1
   case LibFunc_strncmp:     // 0,1
   case LibFunc_strcspn:     // 0,1
-  case LibFunc_strcoll:     // 0,1
+    Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyAccessesArgMemory(F);
+    Changed |= setOnlyReadsMemory(F);
+    Changed |= setDoesNotCapture(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    return Changed;
+  case LibFunc_strcoll:
   case LibFunc_strcasecmp:  // 0,1
   case LibFunc_strncasecmp: //
+    // Those functions may depend on the locale, which may be accessed through
+    // global memory.
     Changed |= setOnlyReadsMemory(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
@@ -310,6 +319,7 @@
     Changed |= setRetDoesNotAlias(F);
     return Changed;
   case LibFunc_memcmp:
+    Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setOnlyReadsMemory(F);
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
@@ -317,8 +327,9 @@
     return Changed;
   case LibFunc_memchr:
   case LibFunc_memrchr:
-    Changed |= setOnlyReadsMemory(F);
     Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyAccessesArgMemory(F);
+    Changed |= setOnlyReadsMemory(F);
     return Changed;
   case LibFunc_modf:
   case LibFunc_modff:
@@ -327,24 +338,27 @@
     Changed |= setDoesNotCapture(F, 1);
     return Changed;
   case LibFunc_memcpy:
+    Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotAlias(F, 0);
-    Changed |= setDoesNotAlias(F, 1);
     Changed |= setReturnedArg(F, 0);
-    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotAlias(F, 1);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;
   case LibFunc_memmove:
-    Changed |= setReturnedArg(F, 0);
     Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyAccessesArgMemory(F);
+    Changed |= setReturnedArg(F, 0);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;
   case LibFunc_mempcpy:
   case LibFunc_memccpy:
+    Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setDoesNotAlias(F, 0);
     Changed |= setDoesNotAlias(F, 1);
-    Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;
@@ -416,6 +430,7 @@
     return Changed;
   case LibFunc_bcmp:
     Changed |= setDoesNotThrow(F);
+    Changed |= setOnlyAccessesArgMemory(F);
     Changed |= setOnlyReadsMemory(F);
     Changed |= setDoesNotCapture(F, 0);
     Changed |= setDoesNotCapture(F, 1);
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
@@ -241,7 +241,7 @@
 ; CHECK: declare i64 @atoll(i8* nocapture) [[G2]]
 declare i64 @atoll(i8*)
 
-; CHECK-LINUX: declare i32 @bcmp(i8* nocapture, i8* nocapture, i64) [[G2]]
+; CHECK-LINUX: declare i32 @bcmp(i8* nocapture, i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY:#[0-9]+]]
 ; CHECK-DARWIN-NOT: declare i32 @bcmp(i8* nocapture, i8* nocapture, i64) [[G2]]
 ; CHECK-UNKNOWN-NOT: declare i32 @bcmp(i8* nocapture, i8* nocapture, i64) [[G2]]
 ; CHECK-NVPTX-NOT: declare i32 @bcmp(i8* nocapture, i8* nocapture, i64) [[G2]]
@@ -619,22 +619,24 @@
 ; CHECK-LINUX: declare noalias i8* @memalign(i64, i64) [[G0]]
 declare i8* @memalign(i64, i64)
 
-; CHECK: declare i8* @memccpy(i8* noalias, i8* noalias nocapture readonly, i32, i64) [[G1]]
+; CHECK: declare i8* @memccpy(i8* noalias, i8* noalias nocapture readonly, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
 declare i8* @memccpy(i8*, i8*, i32, i64)
 
-; CHECK: declare i8* @memchr(i8*, i32, i64) [[G2]]
+; CHECK-LINUX:   declare i8* @memchr(i8*, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
+; CHECK-DARWIN:  declare i8* @memchr(i8*, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY:#[0-9]+]]
+; CHECK-UNKNOWN: declare i8* @memchr(i8*, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY:#[0-9]+]]
 declare i8* @memchr(i8*, i32, i64)
 
-; CHECK: declare i32 @memcmp(i8* nocapture, i8* nocapture, i64) [[G2]]
+; CHECK: declare i32 @memcmp(i8* nocapture, i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i32 @memcmp(i8*, i8*, i64)
 
-; CHECK: declare i8* @memcpy(i8* noalias returned, i8* noalias nocapture readonly, i64) [[G1]]
+; CHECK: declare i8* @memcpy(i8* noalias returned, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @memcpy(i8*, i8*, i64)
 
-; CHECK: declare i8* @mempcpy(i8* noalias, i8* noalias nocapture readonly, i64) [[G1]]
+; CHECK: declare i8* @mempcpy(i8* noalias, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @mempcpy(i8*, i8*, i64)
 
-; CHECK: declare i8* @memmove(i8* returned, i8* nocapture readonly, i64) [[G1]]
+; CHECK: declare i8* @memmove(i8* returned, i8* nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @memmove(i8*, i8*, i64)
 
 ; CHECK: declare i8* @memset(i8*, i32, i64) [[G0]]
@@ -835,10 +837,10 @@
 ; CHECK: declare i8* @strcat(i8* returned, i8* nocapture readonly) [[G1]]
 declare i8* @strcat(i8*, i8*)
 
-; CHECK: declare i8* @strchr(i8*, i32) [[G2]]
+; CHECK: declare i8* @strchr(i8*, i32) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i8* @strchr(i8*, i32)
 
-; CHECK: declare i32 @strcmp(i8* nocapture, i8* nocapture) [[G2]]
+; CHECK: declare i32 @strcmp(i8* nocapture, i8* nocapture) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i32 @strcmp(i8*, i8*)
 
 ; CHECK: declare i32 @strcoll(i8* nocapture, i8* nocapture) [[G2]]
@@ -847,13 +849,13 @@
 ; CHECK: declare i8* @strcpy(i8* noalias returned, i8* noalias nocapture readonly) [[G1]]
 declare i8* @strcpy(i8*, i8*)
 
-; CHECK: declare i64 @strcspn(i8* nocapture, i8* nocapture) [[G2]]
+; CHECK: declare i64 @strcspn(i8* nocapture, i8* nocapture) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i64 @strcspn(i8*, i8*)
 
 ; CHECK: declare noalias i8* @strdup(i8* nocapture readonly) [[G1]]
 declare i8* @strdup(i8*)
 
-; CHECK: declare i64 @strlen(i8* nocapture) [[G4:#[0-9]+]]
+; CHECK: declare i64 @strlen(i8* nocapture) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i64 @strlen(i8*)
 
 ; CHECK: declare i32 @strncasecmp(i8* nocapture, i8* nocapture, i64) [[G2]]
@@ -862,7 +864,7 @@
 ; CHECK: declare i8* @strncat(i8* returned, i8* nocapture readonly, i64) [[G1]]
 declare i8* @strncat(i8*, i8*, i64)
 
-; CHECK: declare i32 @strncmp(i8* nocapture, i8* nocapture, i64) [[G2]]
+; CHECK: declare i32 @strncmp(i8* nocapture, i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i32 @strncmp(i8*, i8*, i64)
 
 ; CHECK: declare i8* @strncpy(i8* noalias returned, i8* noalias nocapture readonly, i64) [[G1]]
@@ -877,10 +879,10 @@
 ; CHECK: declare i8* @strpbrk(i8*, i8* nocapture) [[G2]]
 declare i8* @strpbrk(i8*, i8*)
 
-; CHECK: declare i8* @strrchr(i8*, i32) [[G2]]
+; CHECK: declare i8* @strrchr(i8*, i32) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i8* @strrchr(i8*, i32)
 
-; CHECK: declare i64 @strspn(i8* nocapture, i8* nocapture) [[G2]]
+; CHECK: declare i64 @strspn(i8* nocapture, i8* nocapture) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]
 declare i64 @strspn(i8*, i8*)
 
 ; CHECK: declare i8* @strstr(i8*, i8* nocapture) [[G2]]
@@ -1005,12 +1007,13 @@
 
 
 ; memset_pattern16 isn't available everywhere.
-; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture, i8* nocapture readonly, i64) [[G5:#[0-9]+]]
+; CHECK-DARWIN: declare void @memset_pattern16(i8* nocapture, i8* nocapture readonly, i64) [[G6:#[0-9]+]]
 declare void @memset_pattern16(i8*, i8*, i64)
 
 ; CHECK: attributes [[G0]] = { nofree }
 ; CHECK: attributes [[G1]] = { nofree nounwind }
-; CHECK: attributes [[G2]] = { nofree nounwind readonly }
-; CHECK: attributes [[G3]] = { nounwind }
-; CHECK: attributes [[G4]] = { argmemonly nofree nounwind readonly }
-; CHECK-DARWIN: attributes [[G5]] = { argmemonly nofree }
+; CHECK-DAG: attributes [[G2]] = { nofree nounwind readonly }
+; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]] = { argmemonly nofree nounwind readonly }
+; CHECK-DAG: attributes [[G3]] = { nounwind }
+; CHECK-DAG: attributes [[ARGMEMONLY_NOFREE_NOUNWIND]] = { argmemonly nofree nounwind }
+; CHECK-DARWIN: attributes [[G6]] = { argmemonly nofree }