MIPS16/GAS: Fix forced size suffixes with argumentless instructions

Correct the handling of `.e' and `.t' instruction size suffixes with
instruction mnemonics which are not followed by any text on the same
line, such as arguments or white space, e.g.:

$ cat test.s
	.set	mips16
foo:
	entry.t		# comment
	entry.t
	exit.t		# comment
	exit.t
	nop.t		# comment
	nop.t
$ as -32 -o test.o test.s
test.s: Assembler messages:
test.s:4: Error: unrecognized opcode `entry.t'
test.s:6: Error: unrecognized opcode `exit.t'
test.s:8: Error: unrecognized opcode `nop.t'
$

	gas/
	* config/tc-mips.c (mips16_ip): Handle `.e' and `.t' instruction
	suffixes followed by a null character rather than a space too.
	* testsuite/gas/mips/mips16-insn-length-noargs.d: New test.
	* testsuite/gas/mips/mips16-insn-length-noargs.s: New test
	source.
	* testsuite/gas/mips/mips.exp: Run the new test.

gas/ChangeLog

@@ -1,3 +1,12 @@
+2016-12-23  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* config/tc-mips.c (mips16_ip): Handle `.e' and `.t' instruction
+	suffixes followed by a null character rather than a space too.
+	* testsuite/gas/mips/mips16-insn-length-noargs.d: New test.
+	* testsuite/gas/mips/mips16-insn-length-noargs.s: New test
+	source.
+	* testsuite/gas/mips/mips.exp: Run the new test.
+
 2016-12-23  Maciej W. Rozycki  <macro@imgtec.com>
 
 	* testsuite/gas/mips/mips16-extend-swap.d: New test.

gas/config/tc-mips.c

@@ -13857,13 +13857,14 @@ mips16_ip (char *str, struct mips_cl_insn *insn)
   char *end, *s, c;
   struct mips_opcode *first;
   struct mips_operand_token *tokens;
-
-  forced_insn_length = 0;
+  unsigned int l;
 
   for (s = str; ISLOWER (*s); ++s)
     ;
   end = s;
   c = *end;
+
+  l = 0;
   switch (c)
     {
     case '\0':
@@ -13874,23 +13875,27 @@ mips16_ip (char *str, struct mips_cl_insn *insn)
       break;
 
     case '.':
-      if (s[1] == 't' && s[2] == ' ')
+      s++;
+      if (*s == 't')
 	{
-	  forced_insn_length = 2;
-	  s += 3;
-	  break;
+	  l = 2;
+	  s++;
 	}
-      else if (s[1] == 'e' && s[2] == ' ')
+      else if (*s == 'e')
 	{
-	  forced_insn_length = 4;
-	  s += 3;
-	  break;
+	  l = 4;
+	  s++;
 	}
+      if (*s == '\0')
+	break;
+      else if (*s++ == ' ')
+	break;
       /* Fall through.  */
     default:
       set_insn_error (0, _("unrecognized opcode"));
       return;
     }
+  forced_insn_length = l;
 
   *end = 0;
   first = (struct mips_opcode *) hash_find (mips16_op_hash, str);

gas/testsuite/gas/mips/mips.exp

@@ -1344,6 +1344,7 @@ if { [istarget mips*-*-vxworks*] } {
     run_dump_test "mips16-extend-swap"
     run_dump_test "mips16-sprel-swap"
     run_dump_test "mips16-sdrasp"
+    run_dump_test "mips16-insn-length-noargs"
 
     run_dump_test "mips16-branch-unextended-1"
     run_dump_test "mips16-branch-unextended-2"

gas/testsuite/gas/mips/mips16-insn-length-noargs.d

@@ -0,0 +1,14 @@
+#objdump: -d --prefix-addresses --show-raw-insn
+#name: MIPS16 argumentless instruction size override
+#as: -32
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+[0-9a-f]+ <[^>]*> e809      	entry
+[0-9a-f]+ <[^>]*> e809      	entry
+[0-9a-f]+ <[^>]*> ef09      	exit
+[0-9a-f]+ <[^>]*> ef09      	exit
+[0-9a-f]+ <[^>]*> 6500      	nop
+[0-9a-f]+ <[^>]*> 6500      	nop
+	\.\.\.

gas/testsuite/gas/mips/mips16-insn-length-noargs.s

@@ -0,0 +1,12 @@
+	.set	mips16
+foo:
+	entry.t		# comment
+	entry.t
+	exit.t		# comment
+	exit.t
+	nop.t		# comment
+	nop.t
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16