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
@@ -637,11 +637,20 @@
                                                    LibFunc F,
                                                    const DataLayout *DL) const {
   LLVMContext &Ctx = FTy.getContext();
-  Type *PCharTy = Type::getInt8PtrTy(Ctx);
   Type *SizeTTy = DL ? DL->getIntPtrType(Ctx, /*AddressSpace=*/0) : nullptr;
   auto IsSizeTTy = [SizeTTy](Type *Ty) {
     return SizeTTy ? Ty == SizeTTy : Ty->isIntegerTy();
   };
+  auto IsCharPtrTy = [DL](Type *Ty) {
+    if (auto PTy = dyn_cast<PointerType>(Ty)) {
+      // XXX: should we restrict this to i8* in the default globals AS?
+      if (DL &&
+          PTy->getPointerAddressSpace() != DL->getDefaultGlobalsAddressSpace())
+        return false;
+      return PTy->getPointerElementType()->isIntegerTy(8);
+    }
+    return false;
+  };
   unsigned NumParams = FTy.getNumParams();
 
   switch (F) {
@@ -719,7 +728,7 @@
   case LibFunc_stpcpy:
     return (NumParams == 2 && FTy.getReturnType() == FTy.getParamType(0) &&
             FTy.getParamType(0) == FTy.getParamType(1) &&
-            FTy.getParamType(0) == PCharTy);
+            IsCharPtrTy(FTy.getParamType(0)));
 
   case LibFunc_strlcat_chk:
   case LibFunc_strlcpy_chk:
@@ -744,8 +753,7 @@
   case LibFunc_stpncpy:
     return (NumParams == 3 && FTy.getReturnType() == FTy.getParamType(0) &&
             FTy.getParamType(0) == FTy.getParamType(1) &&
-            FTy.getParamType(0) == PCharTy &&
-            IsSizeTTy(FTy.getParamType(2)));
+            IsCharPtrTy(FTy.getParamType(0)) && IsSizeTTy(FTy.getParamType(2)));
 
   case LibFunc_strxfrm:
     return (NumParams == 3 && FTy.getParamType(0)->isPointerTy() &&
@@ -885,7 +893,7 @@
     return (FTy.getReturnType()->isPointerTy());
   case LibFunc_realloc:
   case LibFunc_reallocf:
-    return (NumParams == 2 && FTy.getReturnType() == PCharTy &&
+    return (NumParams == 2 && IsCharPtrTy(FTy.getReturnType()) &&
             FTy.getParamType(0) == FTy.getReturnType() &&
             IsSizeTTy(FTy.getParamType(1)));
   case LibFunc_read:
@@ -1014,7 +1022,7 @@
   case LibFunc_getchar_unlocked:
     return (NumParams == 0 && FTy.getReturnType()->isIntegerTy());
   case LibFunc_gets:
-    return (NumParams == 1 && FTy.getParamType(0) == PCharTy);
+    return (NumParams == 1 && IsCharPtrTy(FTy.getParamType(0)));
   case LibFunc_getitimer:
     return (NumParams == 2 && FTy.getParamType(1)->isPointerTy());
   case LibFunc_ungetc:
@@ -1470,13 +1478,12 @@
 
   case LibFunc_strnlen:
     return (NumParams == 2 && FTy.getReturnType() == FTy.getParamType(1) &&
-            FTy.getParamType(0) == PCharTy &&
-            FTy.getParamType(1) == SizeTTy);
+            IsCharPtrTy(FTy.getParamType(0)) && IsSizeTTy(FTy.getParamType(1)));
 
   case LibFunc_posix_memalign:
     return (NumParams == 3 && FTy.getReturnType()->isIntegerTy(32) &&
             FTy.getParamType(0)->isPointerTy() &&
-            FTy.getParamType(1) == SizeTTy && FTy.getParamType(2) == SizeTTy);
+            IsSizeTTy(FTy.getParamType(1)) && IsSizeTTy(FTy.getParamType(2)));
 
   case LibFunc_wcslen:
     return (NumParams == 1 && FTy.getParamType(0)->isPointerTy() &&
diff --git a/llvm/test/Transforms/InstCombine/strcpy-nonzero-as.ll b/llvm/test/Transforms/InstCombine/strcpy-nonzero-as.ll
--- a/llvm/test/Transforms/InstCombine/strcpy-nonzero-as.ll
+++ b/llvm/test/Transforms/InstCombine/strcpy-nonzero-as.ll
@@ -23,7 +23,7 @@
 ; CHECK-AS200-LABEL: define {{[^@]+}}@test_strcpy_to_memcpy
 ; CHECK-AS200-SAME: (i8 addrspace(200)* [[DST:%.*]]) addrspace(200) [[ATTR0:#.*]] {
 ; CHECK-AS200-NEXT:  entry:
-; CHECK-AS200-NEXT:    [[CALL:%.*]] = call addrspace(200) i8 addrspace(200)* @strcpy(i8 addrspace(200)* [[DST]], i8 addrspace(200)* getelementptr inbounds ([17 x i8], [17 x i8] addrspace(200)* @str, i64 0, i64 0))
+; CHECK-AS200-NEXT:    call addrspace(200) void @llvm.memcpy.p200i8.p200i8.i64(i8 addrspace(200)* align 1 dereferenceable(17) [[DST]], i8 addrspace(200)* align 1 dereferenceable(17) getelementptr inbounds ([17 x i8], [17 x i8] addrspace(200)* @str, i64 0, i64 0), i64 17, i1 false)
 ; CHECK-AS200-NEXT:    ret void
 ;
 entry:
@@ -41,7 +41,7 @@
 ; CHECK-AS200-LABEL: define {{[^@]+}}@test_stpcpy_to_memcpy
 ; CHECK-AS200-SAME: (i8 addrspace(200)* [[DST:%.*]]) addrspace(200) [[ATTR0]] {
 ; CHECK-AS200-NEXT:  entry:
-; CHECK-AS200-NEXT:    [[CALL:%.*]] = call addrspace(200) i8 addrspace(200)* @stpcpy(i8 addrspace(200)* [[DST]], i8 addrspace(200)* getelementptr inbounds ([17 x i8], [17 x i8] addrspace(200)* @str, i64 0, i64 0))
+; CHECK-AS200-NEXT:    call addrspace(200) void @llvm.memcpy.p200i8.p200i8.i128(i8 addrspace(200)* align 1 dereferenceable(17) [[DST]], i8 addrspace(200)* align 1 dereferenceable(17) getelementptr inbounds ([17 x i8], [17 x i8] addrspace(200)* @str, i64 0, i64 0), i128 17, i1 false)
 ; CHECK-AS200-NEXT:    ret void
 ;
 entry:
@@ -59,7 +59,7 @@
 ; CHECK-AS200-LABEL: define {{[^@]+}}@test_strncpy_to_memcpy
 ; CHECK-AS200-SAME: (i8 addrspace(200)* [[DST:%.*]]) addrspace(200) [[ATTR0]] {
 ; CHECK-AS200-NEXT:  entry:
-; CHECK-AS200-NEXT:    [[CALL:%.*]] = call addrspace(200) i8 addrspace(200)* @strncpy(i8 addrspace(200)* [[DST]], i8 addrspace(200)* getelementptr inbounds ([17 x i8], [17 x i8] addrspace(200)* @str, i64 0, i64 0), i64 17)
+; CHECK-AS200-NEXT:    call addrspace(200) void @llvm.memcpy.p200i8.p200i8.i128(i8 addrspace(200)* align 1 dereferenceable(17) [[DST]], i8 addrspace(200)* align 1 dereferenceable(17) getelementptr inbounds ([17 x i8], [17 x i8] addrspace(200)* @str, i64 0, i64 0), i128 17, i1 false)
 ; CHECK-AS200-NEXT:    ret void
 ;
 entry: