constraints.md (Cm2): New constraint for int -2.

	* config/avr/constraints.md (Cm2): New constraint for int -2.
	* config/avr/avr.md (addqi3): Use it. New alternatives for +/-2.
	(*negqihi2): New insn.

From-SVN: r181103

gcc/ChangeLog

+2011-11-07  Georg-Johann Lay  <avr@gjlay.de>
+
+	* config/avr/constraints.md (Cm2): New constraint for int -2.
+	* config/avr/avr.md (addqi3): Use it. New alternatives for +/-2.
+	(*negqihi2): New insn.
+
 2011-11-07  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* dwarf2cfi.c (dwarf2out_frame_debug_expr): Check

gcc/config/avr/avr.md

@@ -752,17 +752,19 @@
 ; add bytes
 
 (define_insn "addqi3"
-  [(set (match_operand:QI 0 "register_operand" "=r,d,r,r")
-        (plus:QI (match_operand:QI 1 "register_operand" "%0,0,0,0")
-                 (match_operand:QI 2 "nonmemory_operand" "r,i,P,N")))]
+  [(set (match_operand:QI 0 "register_operand"          "=r,d,r,r,r,r")
+        (plus:QI (match_operand:QI 1 "register_operand" "%0,0,0,0,0,0")
+                 (match_operand:QI 2 "nonmemory_operand" "r,i,P,N,K,Cm2")))]
   ""
   "@
 	add %0,%2
 	subi %0,lo8(-(%2))
 	inc %0
-	dec %0"
-  [(set_attr "length" "1,1,1,1")
-   (set_attr "cc" "set_czn,set_czn,set_zn,set_zn")])
+	dec %0
+	inc %0\;inc %0
+	dec %0\;dec %0"
+  [(set_attr "length" "1,1,1,1,2,2")
+   (set_attr "cc" "set_czn,set_czn,set_zn,set_zn,set_zn,set_zn")])
 
 
 (define_expand "addhi3"
@@ -3386,6 +3388,14 @@
   [(set_attr "length" "1")
    (set_attr "cc" "set_zn")])
 
+(define_insn "*negqihi2"
+  [(set (match_operand:HI 0 "register_operand"                        "=r")
+        (neg:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "0"))))]
+  ""
+  "clr %B0\;neg %A0\;brge .+2\;com %B0"
+  [(set_attr "length" "4")
+   (set_attr "cc" "set_n")])
+
 (define_insn "neghi2"
   [(set (match_operand:HI 0 "register_operand"       "=!d,r,&r")
 	(neg:HI (match_operand:HI 1 "register_operand" "0,0,r")))]

gcc/config/avr/constraints.md

@@ -103,6 +103,11 @@
   (and (match_code "mem")
        (match_test "extra_constraint_Q (op)")))
 
+(define_constraint "Cm2"
+  "Constant integer @minus{}2."
+  (and (match_code "const_int")
+       (match_test "ival == -2")))
+
 (define_constraint "C03"
   "Constant integer 3."
   (and (match_code "const_int")