Re: PPro patch for egcs

[hjl at lucon dot org (H.J. Lu)]

> 
> >	* config/i386/i386.c (output_fp_conditional_move): New function
> >	to output floating point conditional move.
> >	(output_int_conditional_move): New function to output integer
> >	conditional move.
> >
> >	* config/i386/i386.md (movsicci+5, movhicc+5, movdicc+5): Call
> >	output_int_conditional_move () to output int conditional move.
> >	(movsfcc+5, movdfcc+5, movxfcc+5): Call
> >	output_fp_conditional_move () to output floating point
> >	conditional move.
> 
> I don't understand why you are checking for which_alternative == 3
> in output_fp_conditional_move.  The define_insn for the floating
> point conditional moves should only result in which_alternative
> equaling 0, 1, or 2.  Any other value should cause an abort.

I forgot to remove 3.

> 
> The special case handling of DImode in output_int_conditional_move
> seems more complicated than the original code associated with the
> define_insn for the DImode integer conditional move.  What is the
> advantage of creating a complicated function?
> 

Ok, I simplified output_int_conditional_move. We have to handle some
special cases for integer conditional move. It is better to do it
in one place.

Here are new output_fp_conditional_move and output_int_conditional_move.

Thanks.


H.J.
------
char *
output_fp_conditional_move (which_alternative, operands)
     int which_alternative;
     rtx operands[];
{
  if (which_alternative == 0)
    {
      /* r <- cond ? arg : r */
      output_asm_insn (AS2 (fcmov%F1,%2,%0), operands);
    }
  else if (which_alternative == 1)
    {
      /* r <- cond ? r : arg */
      output_asm_insn (AS2 (fcmov%f1,%3,%0), operands);
    }
  else if (which_alternative == 2)
    {
      /* r <- cond ? r : arg */
      output_asm_insn (AS2 (fcmov%F1,%2,%0), operands);
      output_asm_insn (AS2 (fcmov%f1,%3,%0), operands);
    }
  else
    abort ();

  return "";
}

char *
output_int_conditional_move (which_alternative, operands)
     int which_alternative;
     rtx operands[];
{
  int code = GET_CODE (operands[1]);
  enum machine_mode mode;
  rtx xops[4];

  if ((code == GT || code == LE)
      && (cc_prev_status.flags & CC_NO_OVERFLOW))
    return NULL_PTR;

  mode = GET_MODE (operands [0]);
  if (mode == DImode)
    {
      xops [0] = gen_rtx_SUBREG (SImode, operands [0], 1);
      xops [1] = operands [1];
      xops [2] = gen_rtx_SUBREG (SImode, operands [2], 1);
      xops [3] = gen_rtx_SUBREG (SImode, operands [3], 1);
    }

  if (which_alternative == 0)
    {
      /* r <- cond ? arg : r */
      output_asm_insn (AS2 (cmov%C1,%2,%0), operands);
      if (mode == DImode)
	output_asm_insn (AS2 (cmov%C1,%2,%0), xops);
    }
  else if (which_alternative == 1)
    {
      /* r <- cond ? r : arg */
      output_asm_insn (AS2 (cmov%c1,%3,%0), operands);
      if (mode == DImode)
	output_asm_insn (AS2 (cmov%c1,%3,%0), xops);
    }
  else if (which_alternative == 2)
    {
      /* rm <- cond ? arg1 : arg2 */
      output_asm_insn (AS2 (cmov%C1,%2,%0), operands);
      output_asm_insn (AS2 (cmov%c1,%3,%0), operands);
      if (mode == DImode)
	{
	  output_asm_insn (AS2 (cmov%C1,%2,%0), xops);
	  output_asm_insn (AS2 (cmov%c1,%3,%0), xops);
	}
    }
  else
    abort ();

  return "";
}