* config/h8300/h8300.md (a new peephole2): New.

From-SVN: r65082

gcc/ChangeLog

+2003-03-31  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* config/h8300/h8300.md (a new peephole2): New.
+
 2003-03-31  Richard Sandiford  <rsandifo@redhat.com>
 
 	* gcse.c (simple_mem): Return false for floating-point accesses

gcc/config/h8300/h8300.md

@@ -3955,6 +3955,50 @@
   "operands[3] = gen_lowpart (HImode, operands[0]);
    operands[4] = gen_lowpart (HImode, operands[1]);")
 
+;; (compare (reg:HI) (const_int)) takes 4 bytes, so we try to achieve
+;; the equivalent with shorter sequences.  Here is the summary.  Cases
+;; are grouped for each define_peephole2.
+;;
+;; reg  const_int                   use     insn
+;; --------------------------------------------------------
+;; dead    -2                       eq/ne   inc.l
+;; dead    -1                       eq/ne   inc.l
+;; dead     1                       eq/ne   dec.l
+;; dead     2                       eq/ne   dec.l
+;;
+;; dead     1                       geu/ltu shlr.l
+;; dead     3 (H8S)                 geu/ltu shlr.l
+;;
+;; dead   255                       geu/ltu mov.b
+
+(define_peephole2
+  [(set (cc0)
+	(compare (match_operand:HI 0 "register_operand" "")
+		 (match_operand:HI 1 "const_int_operand" "")))
+   (set (pc)
+	(if_then_else (match_operator 2 "gtuleu_operator"
+			[(cc0) (const_int 0)])
+		      (label_ref (match_operand 3 "" ""))
+		      (pc)))]
+  "(TARGET_H8300H || TARGET_H8300S)
+   && peep2_reg_dead_p (1, operands[0])
+   && (INTVAL (operands[1]) == 1
+	|| (TARGET_H8300S && INTVAL (operands[1]) == 3))"
+  [(parallel [(set (match_dup 0)
+		   (lshiftrt:HI (match_dup 0)
+				(match_dup 5)))
+	      (clobber (scratch:QI))])
+   (set (cc0)
+	(match_dup 0))
+   (set (pc)
+	(if_then_else (match_dup 4)
+		      (label_ref (match_dup 3))
+		      (pc)))]
+  "operands[4] = ((GET_CODE (operands[2]) == GTU) ?
+		  gen_rtx_NE (VOIDmode, cc0_rtx, const0_rtx) :
+		  gen_rtx_EQ (VOIDmode, cc0_rtx, const0_rtx));
+   operands[5] = GEN_INT (exact_log2 (INTVAL (operands[1]) + 1));")
+
 ;; (compare (reg:SI) (const_int)) takes 6 bytes, so we try to achieve
 ;; the equivalent with shorter sequences.  Here is the summary.  Cases
 ;; are grouped for each define_peephole2.