diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index c9fa5c137bb..85881307f88 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -1049,8 +1049,8 @@ static unsigned getIntelMemOperandSize(StringRef OpStr) {
     .Cases("WORD", "word", 16)
     .Cases("DWORD", "dword", 32)
     .Cases("QWORD", "qword", 64)
+    .Cases("MMWORD","mmword", 64)
     .Cases("XWORD", "xword", 80)
-    //
     .Cases("TBYTE", "tbyte", 80)
     .Cases("XMMWORD", "xmmword", 128)
     .Cases("YMMWORD", "ymmword", 256)
diff --git a/test/MC/X86/intel-syntax.s b/test/MC/X86/intel-syntax.s
index 95527b0eff2..002a6f81dcf 100644
--- a/test/MC/X86/intel-syntax.s
+++ b/test/MC/X86/intel-syntax.s
@@ -705,6 +705,9 @@ repnz cmpsb
 sal eax, 123
 // CHECK: shll	$123, %eax
 
+psignw    mm0, MMWORD PTR t2
+// CHECK: psignw t2, %mm0
+
 comisd xmm0, QWORD PTR [eax]
 comiss xmm0, DWORD PTR [eax]
 vcomisd xmm0, QWORD PTR [eax]