(decrement_and_branchsi and related insns): Don't use a "2" to select a...

(decrement_and_branchsi and related insns): Don't use a "2" to select
a register preference for operand 1 if operand 2 hasn't been seen yet.
Add appropriate clobbers in decrement_and_branchsi.
Add patterns where the pc/label_ref are interchanged.

From-SVN: r10363

gcc/config/rs6000/rs6000.md

@@ -7265,25 +7265,33 @@
 ;; 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")
+  [(parallel [(set (match_operand:SI 0 "register_operand" "")
+		   (plus:SI (match_dup 0)
+			    (const_int -1)))
+	      (set (pc) (if_then_else (ne (match_dup 0)
 					  (const_int 1))
 				      (label_ref (match_operand 1 "" ""))
 				      (pc)))
-	      (set (match_dup 0) (plus:SI (match_dup 0) (const_int -1)))])]
+	      (clobber (match_scratch:CC 2 ""))
+	      (clobber (match_scratch:SI 3 ""))])]
   ""
   "")
 
 ;; 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.
+;; In order that the length attribute is calculated correctly, the
+;; label MUST be operand 0.
+
 (define_insn ""
   [(set (pc)
-	(if_then_else (ne (match_operand:SI 1 "register_operand" "2,*r,*r")
+	(if_then_else (ne (match_operand:SI 1 "register_operand" "c,*r,*r")
 			  (const_int 1))
 		      (label_ref (match_operand 0 "" ""))
 		      (pc)))
-   (set (match_operand:SI 2 "register_operand" "=c,*r,m*q*c*l")
-	(plus:SI (match_dup 1) (const_int -1)))
+   (set (match_operand:SI 2 "register_operand" "=1,*r,m*q*c*l")
+	(plus:SI (match_dup 1)
+		 (const_int -1)))
    (clobber (match_scratch:CC 3 "=X,&x,&x"))
    (clobber (match_scratch:SI 4 "=X,X,r"))]
   ""
@@ -7299,15 +7307,40 @@
   [(set_attr "type" "branch")
    (set_attr "length" "*,12,16")])
 
+(define_insn ""
+  [(set (pc)
+	(if_then_else (ne (match_operand:SI 1 "register_operand" "c,*r,*r")
+			  (const_int 1))
+		      (pc)
+		      (label_ref (match_operand 0 "" ""))))
+   (set (match_operand:SI 2 "register_operand" "=1,*r,m*q*c*l")
+	(plus:SI (match_dup 1)
+		 (const_int -1)))
+   (clobber (match_scratch:CC 3 "=X,&x,&x"))
+   (clobber (match_scratch:SI 4 "=X,X,r"))]
+  ""
+  "*
+{
+  if (which_alternative != 0)
+    return \"#\";
+  else if (get_attr_length (insn) == 8)
+    return \"bdz %l0\";
+  else
+    return \"{bdn|bdnz} $+8\;b %l0\";
+}"
+  [(set_attr "type" "branch")
+   (set_attr "length" "*,12,16")])
+
 ;; 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" "2,*r,*r")
+	(if_then_else (ge (match_operand:SI 1 "register_operand" "c,*r,*r")
 			  (const_int 0))
 		      (label_ref (match_operand 0 "" ""))
 		      (pc)))
-   (set (match_operand:SI 2 "register_operand" "=c,*r,m*q*c*l")
-	(plus:SI (match_dup 1) (const_int -1)))
+   (set (match_operand:SI 2 "register_operand" "=1,*r,m*q*c*l")
+	(plus:SI (match_dup 1)
+		 (const_int -1)))
    (clobber (match_scratch:CC 3 "=X,&x,&X"))
    (clobber (match_scratch:SI 4 "=X,X,r"))]
   "find_reg_note (insn, REG_NONNEG, 0)"
@@ -7325,12 +7358,37 @@
 
 (define_insn ""
   [(set (pc)
-	(if_then_else (eq (match_operand:SI 1 "register_operand" "2,*r,*r")
+	(if_then_else (ge (match_operand:SI 1 "register_operand" "c,*r,*r")
+			  (const_int 0))
+		      (pc)
+		      (label_ref (match_operand 0 "" ""))))
+   (set (match_operand:SI 2 "register_operand" "=1,*r,m*q*c*l")
+	(plus:SI (match_dup 1)
+		 (const_int -1)))
+   (clobber (match_scratch:CC 3 "=X,&x,&X"))
+   (clobber (match_scratch:SI 4 "=X,X,r"))]
+  "find_reg_note (insn, REG_NONNEG, 0)"
+  "*
+{
+  if (which_alternative != 0)
+    return \"#\";
+  else if (get_attr_length (insn) == 8)
+    return \"bdz %l0\";
+  else
+    return \"{bdn|bdnz} $+8\;b %l0\";
+}"
+  [(set_attr "type" "branch")
+   (set_attr "length" "*,12,16")])
+
+(define_insn ""
+  [(set (pc)
+	(if_then_else (eq (match_operand:SI 1 "register_operand" "c,*r,*r")
 			  (const_int 1))
 		      (label_ref (match_operand 0 "" ""))
 		      (pc)))
-   (set (match_operand:SI 2 "register_operand" "=c,*r,m*q*c*l")
-	(plus:SI (match_dup 1) (const_int -1)))
+   (set (match_operand:SI 2 "register_operand" "=1,*r,m*q*c*l")
+	(plus:SI (match_dup 1)
+		 (const_int -1)))
    (clobber (match_scratch:CC 3 "=X,&x,&x"))
    (clobber (match_scratch:SI 4 "=X,X,r"))]
   ""
@@ -7346,6 +7404,30 @@
   [(set_attr "type" "branch")
    (set_attr "length" "*,12,16")])
 
+(define_insn ""
+  [(set (pc)
+	(if_then_else (eq (match_operand:SI 1 "register_operand" "c,*r,*r")
+			  (const_int 1))
+		      (pc)
+		      (label_ref (match_operand 0 "" ""))))
+   (set (match_operand:SI 2 "register_operand" "=1,*r,m*q*c*l")
+	(plus:SI (match_dup 1)
+		 (const_int -1)))
+   (clobber (match_scratch:CC 3 "=X,&x,&x"))
+   (clobber (match_scratch:SI 4 "=X,X,r"))]
+  ""
+  "*
+{
+  if (which_alternative != 0)
+    return \"#\";
+  else if (get_attr_length (insn) == 8)
+    return \"{bdn|bdnz} %l0\";
+  else
+    return \"bdz $+8\;b %l0\";
+}"
+  [(set_attr "type" "branch")
+   (set_attr "length" "*,12,16")])
+
 (define_split
   [(set (pc)
 	(if_then_else (match_operator 2 "comparison_operator"
@@ -7354,15 +7436,21 @@
 		      (match_operand 5 "" "")
 		      (match_operand 6 "" "")))
    (set (match_operand:SI 0 "gpc_reg_operand" "")
-	(plus:SI (match_dup 1) (const_int -1)))
+	(plus:SI (match_dup 1)
+		 (const_int -1)))
    (clobber (match_scratch:CC 3 ""))
    (clobber (match_scratch:SI 4 ""))]
   "reload_completed"
   [(parallel [(set (match_dup 3)
-		   (compare:CC (plus:SI (match_dup 1) (const_int -1))
+		   (compare:CC (plus:SI (match_dup 1)
+					(const_int -1))
 			       (const_int 0)))
-	      (set (match_dup 0) (plus:SI (match_dup 1) (const_int -1)))])
-   (set (pc) (if_then_else (match_dup 7) (match_dup 5) (match_dup 6)))]
+	      (set (match_dup 0)
+		   (plus:SI (match_dup 1)
+			    (const_int -1)))])
+   (set (pc) (if_then_else (match_dup 7)
+			   (match_dup 5)
+			   (match_dup 6)))]
   "
 { operands[7] = gen_rtx (GET_CODE (operands[2]), VOIDmode, operands[3],
 			 const0_rtx); }")
@@ -7380,11 +7468,17 @@
    (clobber (match_scratch:SI 4 ""))]
   "reload_completed && ! gpc_reg_operand (operands[0], SImode)"
   [(parallel [(set (match_dup 3)
-		   (compare:CC (plus:SI (match_dup 1) (const_int -1))
+		   (compare:CC (plus:SI (match_dup 1)
+					(const_int -1))
 			       (const_int 0)))
-	      (set (match_dup 4) (plus:SI (match_dup 1) (const_int -1)))])
-   (set (match_dup 0) (match_dup 4))
-   (set (pc) (if_then_else (match_dup 7) (match_dup 5) (match_dup 6)))]
+	      (set (match_dup 4)
+		   (plus:SI (match_dup 1)
+			    (const_int -1)))])
+   (set (match_dup 0)
+	(match_dup 4))
+   (set (pc) (if_then_else (match_dup 7)
+			   (match_dup 5)
+			   (match_dup 6)))]
   "
 { operands[7] = gen_rtx (GET_CODE (operands[2]), VOIDmode, operands[3],
 			 const0_rtx); }")