arm.md (smaxsi3): Make aware of smax_m1.

	* arm.md (smaxsi3): Make aware of smax_m1.
	(smax_m1): New.

From-SVN: r110443

gcc/ChangeLog

+2006-01-31  Nicolas Pitre  <nico@cam.org>
+
+	* arm.md (smaxsi3): Make aware of smax_m1.
+	(smax_m1): New.
+
 2006-01-31  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* gcc/config/m68k/lb1sf68.asm: Use moveq to load small constants.

gcc/config/arm/arm.md

@@ -2481,7 +2481,7 @@
     (clobber (reg:CC CC_REGNUM))])]
   "TARGET_ARM"
   "
-  if (operands[2] == const0_rtx)
+  if (operands[2] == const0_rtx || operands[2] == constm1_rtx)
     {
       /* No need for a clobber of the condition code register here.  */
       emit_insn (gen_rtx_SET (VOIDmode, operands[0],
@@ -2500,6 +2500,15 @@
   [(set_attr "predicable" "yes")]
 )
 
+(define_insn "*smax_m1"
+  [(set (match_operand:SI 0 "s_register_operand" "=r")
+	(smax:SI (match_operand:SI 1 "s_register_operand" "r")
+		 (const_int -1)))]
+  "TARGET_ARM"
+  "orr%?\\t%0, %1, %1, asr #31"
+  [(set_attr "predicable" "yes")]
+)
+
 (define_insn "*smax_insn"
   [(set (match_operand:SI          0 "s_register_operand" "=r,r")
 	(smax:SI (match_operand:SI 1 "s_register_operand"  "%0,?r")