c/2500: ide-cd.c from linux-2.4.2 does not compile correctly with -O

[scott snyder]

>No code is compiled for 2 lines in this loop:

I'm gonna take a wild shot in the dark here: this sounds at least
superfically similar to optimization/487, that i reported a while
ago.  You might see if the following patch helps.  It cures
the above-reported bug for me (but i'm not convinced that this
is really the correct way to solve it).

sss

2000-08-24  scott snyder  <snyder@fnal.gov>

        * function.c (assign_parms): Don't mark a parm as eliminable if
        its stack rtx is unchanging.

Index: function.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/function.c,v
retrieving revision 1.250.2.4
diff -u -p -c -r1.250.2.4 function.c
*** function.c	2001/03/15 19:02:00	1.250.2.4
--- function.c	2001/04/06 03:51:38
*************** assign_parms (fndecl)
*** 4911,4916 ****
--- 4911,4919 ----
  	      && stack_parm != 0
  	      && GET_CODE (stack_parm) == MEM
  	      && stack_offset.var == 0
+ #if 1 /* sss */
+               && !RTX_UNCHANGING_P (stack_parm)
+ #endif
  	      && reg_mentioned_p (virtual_incoming_args_rtx,
  				  XEXP (stack_parm, 0)))
  	    {