alpha bootstrap fix

[Richard Henderson <rth at redhat dot com>]

Thu May 17 23:19:46 CEST 2001  Jan Hubicka  <jh@suse.cz>

        * combine.c (combine_simplify_rtx): Use swap_commutative_operands_p.
        (gen_binary): Likewise.
        * optabs.c (emit_cmp_and_jump_insns, emit_conditional_move): Likewise.
        * simplify-rtx.c (simplify_gen_binary,
        simplify_gen_relational): Likewise.

The change to emit_cmp_and_jump_insns, at minimum, is incorrect.
This is used e.g. by compare_from_rtx from emit_store_flag to 
generate setcc instructions.  We have no way of mentioning this
change of comparison code to upper layers, resulting in bad code.

A reduced test case is

----
static unsigned int expr_hash_table_size = 1;

int
main ()
{
  int del = 1;
  unsigned int i = 0;

  if (i < expr_hash_table_size && del)
    exit (0);
  abort ();
}
----

Fixed thus.


r~


	* optabs.c (emit_cmp_and_jump_insns): Don't swap commutative
	operands unless the operation is commutative.

Index: optabs.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/optabs.c,v
retrieving revision 1.97
diff -c -p -d -r1.97 optabs.c
*** optabs.c	2001/05/17 21:21:21	1.97
--- optabs.c	2001/05/21 01:22:23
*************** emit_cmp_and_jump_insns (x, y, compariso
*** 3289,3301 ****
  {
    rtx op0;
    rtx op1;
! 	  
!   if (swap_commutative_operands_p (x, y))
      {
        /* Swap operands and condition to ensure canonical RTL.  */
        op0 = y;
        op1 = x;
-       comparison = swap_condition (comparison);
      }
    else
      {
--- 3289,3304 ----
  {
    rtx op0;
    rtx op1;
! 
!   /* We may not swap in the general case, since this is called from 
!      compare_from_rtx, and we have no way of reporting the changed
!      comparison code.  */
!   if (comparison == swap_condition (comparison)
!       && swap_commutative_operands_p (x, y))
      {
        /* Swap operands and condition to ensure canonical RTL.  */
        op0 = y;
        op1 = x;
      }
    else
      {