diff --git a/llvm/include/llvm/MC/MCParser/MCAsmParser.h b/llvm/include/llvm/MC/MCParser/MCAsmParser.h
--- a/llvm/include/llvm/MC/MCParser/MCAsmParser.h
+++ b/llvm/include/llvm/MC/MCParser/MCAsmParser.h
@@ -260,6 +260,8 @@
 
   bool parseMany(function_ref<bool()> parseOne, bool hasComma = true);
 
+  bool parseManyWithOptionalComma(function_ref<bool()> parseOne);
+
   bool parseIntToken(int64_t &V, const Twine &ErrMsg);
 
   bool check(bool P, const Twine &Msg);
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -3014,7 +3014,7 @@
     return false;
   };
 
-  if (parseMany(parseOp))
+  if (parseManyWithOptionalComma(parseOp))
     return addErrorSuffix(" in '" + Twine(IDVal) + "' directive");
   return false;
 }
diff --git a/llvm/lib/MC/MCParser/MCAsmParser.cpp b/llvm/lib/MC/MCParser/MCAsmParser.cpp
--- a/llvm/lib/MC/MCParser/MCAsmParser.cpp
+++ b/llvm/lib/MC/MCParser/MCAsmParser.cpp
@@ -128,6 +128,21 @@
   return false;
 }
 
+bool MCAsmParser::parseManyWithOptionalComma(function_ref<bool()> parseOne) {
+  if (parseOptionalToken(AsmToken::EndOfStatement))
+    return false;
+  while (true) {
+    if (parseOne())
+      return true;
+    if (parseOptionalToken(AsmToken::EndOfStatement))
+      return false;
+    if (parseOptionalToken(AsmToken::Comma) &&
+        check(getTok().isNot(AsmToken::String), "expected string"))
+      return true;
+  }
+  return false;
+}
+
 bool MCAsmParser::parseExpression(const MCExpr *&Res) {
   SMLoc L;
   return parseExpression(Res, L);
diff --git a/llvm/test/MC/AsmParser/AArch64/directive-parse-err.s b/llvm/test/MC/AsmParser/AArch64/directive-parse-err.s
--- a/llvm/test/MC/AsmParser/AArch64/directive-parse-err.s
+++ b/llvm/test/MC/AsmParser/AArch64/directive-parse-err.s
@@ -13,15 +13,15 @@
 	.set   ident3, 0 $
 	// CHECK-NOT: [[@LINE+1]]:{{[0-9]+}}: error:
 	.set   ident3, 0 // EOL COMMENT
-	// CHECK: [[@LINE+1]]:20: error: unexpected token in '.ascii' directive
+	// CHECK: [[@LINE+1]]:20: error: expected string in '.ascii' directive
 	.ascii  "string1" $
 	// CHECK-NOT: [[@LINE+1]]:{{[0-9]+}}: error:
 	.ascii  "string1" // EOL COMMENT
-	// CHECK: [[@LINE+1]]:20: error: unexpected token in '.asciz' directive
+	// CHECK: [[@LINE+1]]:20: error: expected string in '.asciz' directive
 	.asciz  "string2" $
 	// CHECK-NOT: [[@LINE+1]]:{{[0-9]+}}: error:
 	.asciz  "string2" // EOL COMMENT
-	// CHECK: [[@LINE+1]]:20: error: unexpected token in '.string' directive
+	// CHECK: [[@LINE+1]]:20: error: expected string in '.string' directive
 	.string "string3" $	
 	// CHECK-NOT: [[@LINE+1]]:{{[0-9]+}}: error:
 	.string "string3" // EOL COMMENT	
diff --git a/llvm/test/MC/AsmParser/directive_ascii.s b/llvm/test/MC/AsmParser/directive_ascii.s
--- a/llvm/test/MC/AsmParser/directive_ascii.s
+++ b/llvm/test/MC/AsmParser/directive_ascii.s
@@ -15,36 +15,64 @@
         .ascii "A"
 
 # CHECK: TEST3:
-# CHECK: .byte 66
-# CHECK: .byte 0
-# CHECK: .byte 67
-# CHECK: .byte 0
-TEST3:  
-        .asciz "B", "C"
-        
-# CHECK: TEST4:
 # CHECK: .asciz "\001\001\007\0008\001\0001\200"
-TEST4:  
+TEST3:  
         .ascii "\1\01\07\08\001\0001\200\0"
         
-# CHECK: TEST5:
+# CHECK: TEST4:
 # CHECK: .ascii "\b\f\n\r\t\\\""
-TEST5:
+TEST4:
         .ascii "\b\f\n\r\t\\\""
         
+# CHECK: TEST5:
+# CHECK: .ascii "dk"
+#  0xFACE & 0xFF == 0xCE == 0o316
+#  0x0FE  & 0xFF == 0xFE == 0o376
+# CHECK: .ascii "\316\376"
+TEST5:
+        .ascii "\x64\Xa6B"
+        .ascii "\xface\x0Fe"
+
 # CHECK: TEST6:
+# CHECK: .byte 65
 # CHECK: .byte 66
-# CHECK: .byte 0
 # CHECK: .byte 67
-# CHECK: .byte 0
 TEST6:
-        .string "B", "C"
+        .ascii "A", "B" "C"
 
 # CHECK: TEST7:
-# CHECK: .ascii "dk"
-#  0xFACE & 0xFF == 0xCE == 0o316
-#  0x0FE  & 0xFF == 0xFE == 0o376
-# CHECK: .ascii "\316\376"
+# CHECK: .ascii "ABC"
 TEST7:
-        .ascii "\x64\Xa6B"
-        .ascii "\xface\x0Fe"
+        .ascii "ABC"
+
+# CHECK: TEST8:
+# CHECK: .byte 65
+# CHECK: .byte 0
+# CHECK: .byte 66
+# CHECK: .byte 0
+# CHECK: .byte 67
+# CHECK: .byte 0
+TEST8:
+        .asciz "A", "B" "C"
+
+# CHECK: TEST9:
+# CHECK: .ascii "A\000B\000C"
+# CHECK: .byte 0
+TEST9:
+        .asciz "A\0B\0C"
+
+# CHECK: TEST10:
+# CHECK: .byte 65
+# CHECK: .byte 0
+# CHECK: .byte 66
+# CHECK: .byte 0
+# CHECK: .byte 67
+# CHECK: .byte 0
+TEST10:
+        .string "A", "B" "C"
+
+# CHECK: TEST11:
+# CHECK: .ascii "A\000B\000C"
+# CHECK: .byte 0
+TEST11:
+        .string "A\0B\0C"
diff --git a/llvm/test/MC/Mips/asciiz-directive-bad.s b/llvm/test/MC/Mips/asciiz-directive-bad.s
--- a/llvm/test/MC/Mips/asciiz-directive-bad.s
+++ b/llvm/test/MC/Mips/asciiz-directive-bad.s
@@ -3,6 +3,6 @@
   .asciiz 12
 # CHECK: :[[@LINE-1]]:11: error: expected string in '.asciiz' directive
   .asciiz "a"3
-# CHECK: :[[@LINE-1]]:14: error: unexpected token in '.asciiz' directive
+# CHECK: :[[@LINE-1]]:14: error: expected string in '.asciiz' directive
   .asciiz "a",
 # CHECK: :[[@LINE-1]]:15: error: expected string in '.asciiz' directive