re PR rtl-optimization/8178 (__builtin_ffs broken with -march=k6)

	PR optimization/8178
	* config/i386/i386.md (*movsi_zero): Delete.
	(*ffs_no_cmove): Use ix86_expand_clear to zero the third operand.

Co-Authored-By: Richard Henderson <rth@redhat.com>

From-SVN: r72680

gcc/ChangeLog

+2003-10-19  Eric Botcazou  <ebotcazou@libertysurf.fr>
+            Richard Henderson  <rth@redhat.com>
+
+	PR optimization/8178
+	* config/i386/i386.md (*movsi_zero): Delete.
+	(*ffs_no_cmove): Use ix86_expand_clear to zero the third operand.
+
 2003-10-19  Richard Henderson  <rth@redhat.com>
 
 	* config/alpha/alpha.c (fix_operator): New.

gcc/config/i386/i386.md

@@ -1161,15 +1161,6 @@
   [(set_attr "type" "alu1")
    (set_attr "mode" "SI")
    (set_attr "length_immediate" "0")])
-
-(define_insn "*movsi_zero"
-  [(set (match_operand:SI 0 "register_operand" "=r")
-	(match_operand:SI 1 "const0_operand" "i"))
-   (clobber (reg:CC 17))]
-  "reload_completed && (TARGET_USE_MOV0 && !optimize_size)"
-  "mov{l}\t{%1, %0|%0, %1}"
-  [(set_attr "type" "imov")
-   (set_attr "mode" "SI")])
  
 (define_insn "*movsi_or"
   [(set (match_operand:SI 0 "register_operand" "=r")
@@ -14464,9 +14455,7 @@
   ""
   "#"
   "reload_completed"
-  [(parallel [(set (match_dup 2) (const_int 0))
-	      (clobber (reg:CC 17))])
-   (parallel [(set (reg:CCZ 17) (compare:CCZ (match_dup 1) (const_int 0)))
+  [(parallel [(set (reg:CCZ 17) (compare:CCZ (match_dup 1) (const_int 0)))
 	      (set (match_dup 0) (ctz:SI (match_dup 1)))])
    (set (strict_low_part (match_dup 3))
 	(eq:QI (reg:CCZ 17) (const_int 0)))
@@ -14478,6 +14467,7 @@
 	      (clobber (reg:CC 17))])]
 {
   operands[3] = gen_lowpart (QImode, operands[2]);
+  ix86_expand_clear (operands[2]);
 })
 
 (define_insn "*ffssi_1"