regmove.c (fixup_match_1): Undo last change which removed some "useless" code...

        * regmove.c (fixup_match_1): Undo last change which removed some
        "useless" code, and add a comment explaining this.

From-SVN: r17595

gcc/ChangeLog

+1998-01-30  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>
+
+	* regmove.c (fixup_match_1): Undo last change which removed some
+	"useless" code, and add a comment explaining this.
+
 Mon Feb  2 10:47:14 1998  Gavin Koch  (gavin@cygnus.com)
 
 	* mips.c (mips_expand_prologue): Change uses of TARGET_64BIT

gcc/regmove.c

@@ -1216,7 +1216,11 @@ fixup_match_1 (insn, set, src, src_subreg, dst, backward, operand_number,
 	    }
 	}
     }
-  
+
+  /* Don't remove this seemingly useless if, it is needed to pair with the
+     else in the next two conditionally included code blocks.  */
+  if (0)
+    {;}
 #if defined (HAVE_PRE_INCREMENT) || defined (HAVE_PRE_DECREMENT)
   else if ((code == PLUS || code == MINUS) && insn_const
 	   && try_auto_increment (p, insn, 0, src, insn_const, 1))