Tweaks to X86 instructions to allow the 'w' suffix in places it makes

sense, when the instruction takes the 16-bit ax register or m16 memory
location.  These changes to llvm-mc matches what the darwin assembler
allows for these instructions.  Done differently than in r117031 that
caused a valgrind error which was later reverted.

llvm-svn: 117433

llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp

@@ -705,6 +705,12 @@ ParseInstruction(StringRef Name, SMLoc NameLoc,
     .Case("fildq", "fildll")
     .Case("fcompi", "fcomip")
     .Case("fucompi", "fucomip")
+    .Case("fldcww", "fldcw")
+    .Case("fnstcww", "fnstcw")
+    .Case("fstcww", "fstcw")
+    .Case("fnstsww", "fnstsw")
+    .Case("fstsww", "fstsw")
+    .Case("verrw", "verr")
     .Default(Name);
 
   // FIXME: Hack to recognize cmp<comparison code>{ss,sd,ps,pd}.

llvm/test/MC/X86/x86-32.s

@@ -726,3 +726,51 @@ pshufw $90, %mm4, %mm0
 // CHECK: fucomip	%st(1), %st(0)
 // CHECK:  encoding: [0xdf,0xe9]
         	fucompi
+
+// CHECK: fldcw	32493
+// CHECK:  encoding: [0xd9,0x2d,0xed,0x7e,0x00,0x00]
+        	fldcww	0x7eed
+
+// CHECK: fldcw	32493
+// CHECK:  encoding: [0xd9,0x2d,0xed,0x7e,0x00,0x00]
+        	fldcw	0x7eed
+
+// CHECK: fnstcw	32493
+// CHECK:  encoding: [0xd9,0x3d,0xed,0x7e,0x00,0x00]
+        	fnstcww	0x7eed
+
+// CHECK: fnstcw	32493
+// CHECK:  encoding: [0xd9,0x3d,0xed,0x7e,0x00,0x00]
+        	fnstcw	0x7eed
+
+// CHECK: wait
+// CHECK:  encoding: [0x9b]
+        	fstcww	0x7eed
+
+// CHECK: wait
+// CHECK:  encoding: [0x9b]
+        	fstcw	0x7eed
+
+// CHECK: fnstsw	32493
+// CHECK:  encoding: [0xdd,0x3d,0xed,0x7e,0x00,0x00]
+        	fnstsww	0x7eed
+
+// CHECK: fnstsw	32493
+// CHECK:  encoding: [0xdd,0x3d,0xed,0x7e,0x00,0x00]
+        	fnstsw	0x7eed
+
+// CHECK: wait
+// CHECK:  encoding: [0x9b]
+        	fstsww	0x7eed
+
+// CHECK: wait
+// CHECK:  encoding: [0x9b]
+        	fstsw	0x7eed
+
+// CHECK: verr	32493
+// CHECK:  encoding: [0x0f,0x00,0x25,0xed,0x7e,0x00,0x00]
+        	verrw	0x7eed
+
+// CHECK: verr	32493
+// CHECK:  encoding: [0x0f,0x00,0x25,0xed,0x7e,0x00,0x00]
+        	verr	0x7eed