(ffs): Delete pattern containing nonexistant instruction.

From-SVN: r4620

gcc/config/rs6000/rs6000.md

@@ -435,20 +435,6 @@
   ""
   "neg %0,%1\;and %0,%0,%1\;cntlz %0,%0\;sfi %0,%0,32")
 
-;; There is no need for (set (condition) (compare (ffs) 0)) because that
-;; can be simplified to an ordinary comparison.  A parallel set and compare
-;; might be used, so include it.
-
-(define_insn ""
-  [(set (match_operand:CC 2 "cc_reg_operand" "=x")
-	(compare:CC (ffs:SI (match_operand:SI 1 "register_operand" "r"))
-		    (const_int 0)))
-   (set (match_operand:SI 0 "register_operand" "=&r")
-	(ffs:SI (match_dup 1)))]
-  ""
-  "neg %0,%1\;and %0,%0,%1\;cntlz %0,%0\;sfi. %0,%0,32"
-  [(set_attr "type" "compare")])
-
 (define_insn "mulsi3"
   [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r")
 	(mult:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r")
@@ -4650,7 +4636,18 @@
   ""
   "cror 0,0,0")
 
-;; Define the subtract-one-and-jump insns. 
+;; Define the subtract-one-and-jump insns, starting with the template 
+;; so loop.c knows what to generate.
+
+(define_expand "decrement_and_branchsi"
+  [(parallel [(set (pc) (if_then_else (ne (match_operand:SI 0 "register_operand" "c")
+					  (const_int 1))
+				      (label_ref (match_operand 1 "" ""))
+				      (pc)))
+	      (set (match_dup 0) (plus:SI (match_dup 0) (const_int -1)))])]
+  ""
+  "")
+
 ;; We need to be able to do this for any operand, including MEM, or we
 ;; will cause reload to blow up since we don't allow output reloads on
 ;; JUMP_INSNs. 
@@ -4670,7 +4667,7 @@
    #
    #")
 			       
-;; Similar, but we can use GE since we have a REG_NOTES.
+;; Similar, but we can use GE since we have a REG_NONNEG.
 (define_insn ""
   [(set (pc)
 	(if_then_else (ge (match_operand:SI 1 "register_operand" "0,*r,*r")