Re: CPROP and spec2000 slowdown in mid february

[Jan Hubicka <jh at suse dot cz>]

> I'd prefer to do this by reversing the two choices: so first try t9
> do the global replace.  Then if that fails, try the replace in the
> SET_SRC.  Can you see if that fixes the slowdown and passes tests?
Sorry, once again as I've misspeled the address

Fri May 18 10:59:21 CEST 2001  Jan Hubicka  <jh@suse.cz>

	* gcse.c (try_replace_reg): First try global replace, later try to simplify
	the expression.

Index: gcse.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/gcse.c,v
retrieving revision 1.130
diff -c -3 -p -r1.130 gcse.c
*** gcse.c	2001/05/11 22:07:58	1.130
--- gcse.c	2001/05/18 08:58:33
*************** try_replace_reg (from, to, insn)
*** 4024,4053 ****
    int success = 0;
    rtx set = single_set (insn);
  
    /* If this is a single set, try to simplify the source of the set given
       our substitution.  We could perhaps try this for multiple SETs, but
       it probably won't buy us anything.  */
!   if (set != 0)
      {
        src = simplify_replace_rtx (SET_SRC (set), from, to);
  
!       /* Try this two ways: first just replace SET_SRC.  If that doesn't
! 	 work and this is a PARALLEL, try to replace the whole pattern
! 	 with a new SET.  */
!       if (validate_change (insn, &SET_SRC (set), src, 0))
! 	success = 1;
!       else if (GET_CODE (PATTERN (insn)) == PARALLEL
! 	       && validate_change (insn, &PATTERN (insn),
! 				   gen_rtx_SET (VOIDmode, SET_DEST (set),
! 						src),
! 				   0))
  	success = 1;
      }
  
-   /* Otherwise, try to do a global replacement within the insn.  */
-   if (!success)
-     success = validate_replace_src (from, to, insn);
- 
    /* If we've failed to do replacement, have a single SET, and don't already
       have a note, add a REG_EQUAL note to not lose information.  */
    if (!success && note == 0 && set != 0)
--- 3997,4016 ----
    int success = 0;
    rtx set = single_set (insn);
  
+   success = validate_replace_src (from, to, insn);
+ 
    /* If this is a single set, try to simplify the source of the set given
       our substitution.  We could perhaps try this for multiple SETs, but
       it probably won't buy us anything.  */
!   if (!success && set != 0)
      {
        src = simplify_replace_rtx (SET_SRC (set), from, to);
  
!       if (!rtx_equal_p (src, SET_SRC (set))
! 	  && validate_change (insn, &SET_SRC (set), src, 0))
  	success = 1;
      }
  
    /* If we've failed to do replacement, have a single SET, and don't already
       have a note, add a REG_EQUAL note to not lose information.  */
    if (!success && note == 0 && set != 0)