diff --git a/llvm/include/llvm/Analysis/TargetLibraryInfo.def b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
--- a/llvm/include/llvm/Analysis/TargetLibraryInfo.def
+++ b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
@@ -1048,6 +1048,12 @@
 /// void memset_pattern16(void *b, const void *pattern16, size_t len);
 TLI_DEFINE_ENUM_INTERNAL(memset_pattern16)
 TLI_DEFINE_STRING_INTERNAL("memset_pattern16")
+/// void memset_pattern4(void *b, const void *pattern4, size_t len);
+TLI_DEFINE_ENUM_INTERNAL(memset_pattern4)
+TLI_DEFINE_STRING_INTERNAL("memset_pattern4")
+/// void memset_pattern8(void *b, const void *pattern8, size_t len);
+TLI_DEFINE_ENUM_INTERNAL(memset_pattern8)
+TLI_DEFINE_STRING_INTERNAL("memset_pattern8")
 /// int mkdir(const char *path, mode_t mode);
 TLI_DEFINE_ENUM_INTERNAL(mkdir)
 TLI_DEFINE_STRING_INTERNAL("mkdir")
diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
--- a/llvm/lib/Analysis/TargetLibraryInfo.cpp
+++ b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -166,8 +166,8 @@
     return;
   }
 
-  // memset_pattern16 is only available on iOS 3.0 and Mac OS X 10.5 and later.
-  // All versions of watchOS support it.
+  // memset_pattern{4,8,16} is only available on iOS 3.0 and Mac OS X 10.5 and
+  // later. All versions of watchOS support it.
   if (T.isMacOSX()) {
     // available IO unlocked variants on Mac OS X
     TLI.setAvailable(LibFunc_getc_unlocked);
@@ -175,12 +175,20 @@
     TLI.setAvailable(LibFunc_putc_unlocked);
     TLI.setAvailable(LibFunc_putchar_unlocked);
 
-    if (T.isMacOSXVersionLT(10, 5))
+    if (T.isMacOSXVersionLT(10, 5)) {
+      TLI.setUnavailable(LibFunc_memset_pattern4);
+      TLI.setUnavailable(LibFunc_memset_pattern8);
       TLI.setUnavailable(LibFunc_memset_pattern16);
+    }
   } else if (T.isiOS()) {
-    if (T.isOSVersionLT(3, 0))
+    if (T.isOSVersionLT(3, 0)) {
+      TLI.setUnavailable(LibFunc_memset_pattern4);
+      TLI.setUnavailable(LibFunc_memset_pattern8);
       TLI.setUnavailable(LibFunc_memset_pattern16);
+    }
   } else if (!T.isWatchOS()) {
+    TLI.setUnavailable(LibFunc_memset_pattern4);
+    TLI.setUnavailable(LibFunc_memset_pattern8);
     TLI.setUnavailable(LibFunc_memset_pattern16);
   }
 
@@ -1522,6 +1530,8 @@
             FTy.getParamType(2)->isPointerTy() &&
             FTy.getParamType(3)->isIntegerTy());
 
+  case LibFunc_memset_pattern4:
+  case LibFunc_memset_pattern8:
   case LibFunc_memset_pattern16:
     return (!FTy.isVarArg() && NumParams == 3 &&
             FTy.getParamType(0)->isPointerTy() &&
diff --git a/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml b/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml
--- a/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml
+++ b/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml
@@ -37,7 +37,7 @@
 #
 ## The -COUNT suffix doesn't care if there are too many matches, so check
 ## the exact count first; the two directives should add up to that.
-# AVAIL: TLI knows 466 symbols, 235 available
+# AVAIL: TLI knows 468 symbols, 235 available
 # AVAIL-COUNT-235: {{^}} available
 # UNAVAIL-COUNT-231: not available
 
diff --git a/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp b/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
--- a/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
+++ b/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
@@ -240,6 +240,8 @@
       "declare i8* @memmove(i8*, i8*, i64)\n"
       "declare i8* @memset(i8*, i32, i64)\n"
       "declare void @memset_pattern16(i8*, i8*, i64)\n"
+      "declare void @memset_pattern4(i8*, i8*, i64)\n"
+      "declare void @memset_pattern8(i8*, i8*, i64)\n"
       "declare i32 @mkdir(i8*, i16)\n"
       "declare double @modf(double, double*)\n"
       "declare float @modff(float, float*)\n"
@@ -521,7 +523,8 @@
       "declare i32 @iprintf(i8*, ...)\n"
       "declare i32 @siprintf(i8*, i8*, ...)\n"
 
-      // __small_printf variants have the same prototype as the non-'i' versions.
+      // __small_printf variants have the same prototype as the non-'i'
+      // versions.
       "declare i32 @__small_fprintf(%struct*, i8*, ...)\n"
       "declare i32 @__small_printf(i8*, ...)\n"
       "declare i32 @__small_sprintf(i8*, i8*, ...)\n"
@@ -589,8 +592,7 @@
 
       // These functions are OpenMP Offloading allocation / free routines
       "declare i8* @__kmpc_alloc_shared(i64)\n"
-      "declare void @__kmpc_free_shared(i8*, i64)\n"
-      );
+      "declare void @__kmpc_free_shared(i8*, i64)\n");
 
   for (unsigned FI = 0; FI != LibFunc::NumLibFuncs; ++FI) {
     LibFunc LF = (LibFunc)FI;