(cmpdi): Rewrite to avoid bogus matching constraints.

From-SVN: r9880

gcc/config/m68k/m68k.md

@@ -411,23 +411,33 @@
 
 ;; compare instructions.
 
-(define_insn "cmpdi"
+(define_expand "cmpdi"
+  [(parallel
+    [(set (cc0)
+	  (compare (match_operand:DI 0 "nonimmediate_operand" "")
+		   (match_operand:DI 1 "general_operand" "")))
+     (clobber (match_dup 2))])]
+  ""
+  "
+{
+  operands[2] = gen_reg_rtx (DImode);
+}")
+
+(define_insn ""
   [(set (cc0)
-;;	(compare (match_operand:DI 0 "general_operand" "=&d*a")
-;;	(compare (match_operand:DI 0 "general_operand" "+&d*a")
-;;	(compare (match_operand:DI 0 "general_operand" "+d*a")
-	(compare (match_operand:DI 0 "general_operand" "d*a")
-		 (match_operand:DI 1 "general_operand" "d")))
-   (clobber (match_scratch:DI 2 "=0"))]
+	(compare (match_operand:DI 1 "nonimmediate_operand" "0,d")
+		 (match_operand:DI 2 "general_operand" "d,0")))
+   (clobber (match_operand:DI 0 "register_operand" "=d,d"))]
   ""
   "*
 {
-  operands[2] = gen_rtx (REG, SImode, REGNO (operands[0]) + 1);
-  operands[3] = gen_rtx (REG, SImode, REGNO (operands[1]) + 1);
-  if (DATA_REG_P (operands[0]))
-    return \"sub%.l %3,%2\;subx%.l %1,%0\";
+  if (rtx_equal_p (operands[0], operands[1]))
+    return \"sub%.l %R2,%R0\;subx%.l %2,%0\";
   else
-    return \"exg %/d0,%2\;sub%.l %3,%/d0\;exg %/d0,%0\;subx%.l %1,%/d0\;exg %/d0,%2\";
+    {
+      return \"sub%.l %R1,%R0\;subx%.l %1,%0\";
+      cc_status.flags |= CC_REVERSED;
+    }
 }")
 
 ;; This is the second "hook" for PIC code (in addition to movsi). See