Index: lib/Target/X86/AsmParser/X86AsmParser.cpp
===================================================================
--- lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -1028,6 +1028,7 @@
     .Cases("DWORD", "dword", 32)
     .Cases("QWORD", "qword", 64)
     .Cases("XWORD", "xword", 80)
+    .Cases("TBYTE", "tbyte", 80)
     .Cases("XMMWORD", "xmmword", 128)
     .Cases("YMMWORD", "ymmword", 256)
     .Cases("ZMMWORD", "zmmword", 512)
Index: test/MC/X86/intel-syntax.s
===================================================================
--- test/MC/X86/intel-syntax.s
+++ test/MC/X86/intel-syntax.s
@@ -635,10 +635,12 @@
 // CHECK: addw $1, (%rax)
 // CHECK: addb $1, (%rax)
 
+fstp tbyte ptr [rax]
 fstp xword ptr [rax]
 fstp qword ptr [rax]
 fstp dword ptr [rax]
 // CHECK: fstpt (%rax)
+// CHECK: fstpt (%rax)
 // CHECK: fstpl (%rax)
 // CHECK: fstps (%rax)