[AArch64] Simplify ashl<mode>3 expander for SHORT modes

	* config/aarch64/aarch64.md (ashl<mode>3, SHORT modes):
	Use const_int_operand for operand 2 predicate.  Simplify expand code
	as a result.

From-SVN: r236812

gcc/ChangeLog

+2016-05-27  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* config/aarch64/aarch64.md (ashl<mode>3, SHORT modes):
+	Use const_int_operand for operand 2 predicate.  Simplify expand code
+	as a result.
+
 2016-05-27  Ilya Enkovich  <ilya.enkovich@intel.com>
 
 	PR middle-end/71279

gcc/config/aarch64/aarch64.md

@@ -3880,13 +3880,10 @@
 (define_expand "ashl<mode>3"
   [(set (match_operand:SHORT 0 "register_operand")
 	(ashift:SHORT (match_operand:SHORT 1 "register_operand")
-		      (match_operand:QI 2 "nonmemory_operand")))]
+		      (match_operand:QI 2 "const_int_operand")))]
   ""
   {
-    if (CONST_INT_P (operands[2]))
-      {
-        operands[2] = GEN_INT (INTVAL (operands[2])
-                               & (GET_MODE_BITSIZE (<MODE>mode) - 1));
+    operands[2] = GEN_INT (INTVAL (operands[2]) & GET_MODE_MASK (<MODE>mode));
 
     if (operands[2] == const0_rtx)
       {
@@ -3894,9 +3891,6 @@
 	DONE;
       }
   }
-    else
-      FAIL;
-  }
 )
 
 (define_expand "rotr<mode>3"