Cleaning up expand optabs code

[Richard Sandiford]

Richard Sandiford <richard.sandiford@linaro.org> writes:
> Andreas Krebbel <krebbel@linux.vnet.ibm.com> writes:
>> On 03/22/2011 06:48 PM, Richard Henderson wrote:
>>
>>> Ok.  Watch out for other target problems this week.
>>
>> This unfortunately broke bootstrap on s390.
>
> This is PR 48263.  Since it seems to be affecting several targets,
> and since my bootstrap seems to be taking a looong time, I'll post
> the patch here before testing has finished.

Bootstrap & regression-test on x86_64-linux-gnu now finished.  OK to install?

>> Just copying the pre-patch behaviour fixes the problem for me:
>
> I think we need to undo more of the patch, and leave the conversion
> outside of the new interface.
>
> Sorry for the breakage.
>
> Richard
>
>
> gcc/
> 	PR rtl-optimization/48263
> 	* optabs.c (expand_binop_directly): Reinstate convert_modes code
> 	and original commutative_p handling.  Use maybe_gen_insn.
>
> Index: gcc/optabs.c
> ===================================================================
> --- gcc/optabs.c	2011-03-24 09:18:00.000000000 +0000
> +++ gcc/optabs.c	2011-03-24 09:36:46.000000000 +0000
> @@ -1269,6 +1269,38 @@ expand_binop_directly (enum machine_mode
>    if (!shift_optab_p (binoptab))
>      xop1 = avoid_expensive_constant (mode1, binoptab, xop1, unsignedp);
>  
> +  /* In case the insn wants input operands in modes different from
> +     those of the actual operands, convert the operands.  It would
> +     seem that we don't need to convert CONST_INTs, but we do, so
> +     that they're properly zero-extended, sign-extended or truncated
> +     for their mode.  */
> +
> +  if (GET_MODE (xop0) != mode0 && mode0 != VOIDmode)
> +    xop0 = convert_modes (mode0,
> +			  GET_MODE (xop0) != VOIDmode
> +			  ? GET_MODE (xop0)
> +			  : mode,
> +			  xop0, unsignedp);
> +
> +  if (GET_MODE (xop1) != mode1 && mode1 != VOIDmode)
> +    xop1 = convert_modes (mode1,
> +			  GET_MODE (xop1) != VOIDmode
> +			  ? GET_MODE (xop1)
> +			  : mode,
> +			  xop1, unsignedp);
> +
> +  /* If operation is commutative,
> +     try to make the first operand a register.
> +     Even better, try to make it the same as the target.
> +     Also try to make the last operand a constant.  */
> +  if (commutative_p
> +      && swap_commutative_operands_with_target (target, xop0, xop1))
> +    {
> +      swap = xop1;
> +      xop1 = xop0;
> +      xop0 = swap;
> +    }
> +
>    /* Now, if insn's predicates don't allow our operands, put them into
>       pseudo regs.  */
>  
> @@ -1291,41 +1323,25 @@ expand_binop_directly (enum machine_mode
>      tmp_mode = mode;
>  
>    create_output_operand (&ops[0], target, tmp_mode);
> -  create_convert_operand_from (&ops[1], xop0, mode, unsignedp);
> -  create_convert_operand_from (&ops[2], xop1, mode, unsignedp);
> -  if (maybe_legitimize_operands (icode, 0, 3, ops))
> -    {
> -      /* If operation is commutative,
> -	 try to make the first operand a register.
> -	 Even better, try to make it the same as the target.
> -	 Also try to make the last operand a constant.  */
> -      if (commutative_p
> -	  && swap_commutative_operands_with_target (ops[0].value, ops[1].value,
> -						    ops[2].value))
> -	{
> -	  swap = ops[2].value;
> -	  ops[2].value = ops[1].value;
> -	  ops[1].value = swap;
> -	}
> -
> -      pat = GEN_FCN (icode) (ops[0].value, ops[1].value, ops[2].value);
> -      if (pat)
> +  create_input_operand (&ops[1], xop0, mode0);
> +  create_input_operand (&ops[2], xop1, mode1);
> +  pat = maybe_gen_insn (icode, 3, ops);
> +  if (pat)
> +    {
> +      /* If PAT is composed of more than one insn, try to add an appropriate
> +	 REG_EQUAL note to it.  If we can't because TEMP conflicts with an
> +	 operand, call expand_binop again, this time without a target.  */
> +      if (INSN_P (pat) && NEXT_INSN (pat) != NULL_RTX
> +	  && ! add_equal_note (pat, ops[0].value, binoptab->code,
> +			       ops[1].value, ops[2].value))
>  	{
> -	  /* If PAT is composed of more than one insn, try to add an appropriate
> -	     REG_EQUAL note to it.  If we can't because TEMP conflicts with an
> -	     operand, call expand_binop again, this time without a target.  */
> -	  if (INSN_P (pat) && NEXT_INSN (pat) != NULL_RTX
> -	      && ! add_equal_note (pat, ops[0].value, binoptab->code,
> -				   ops[1].value, ops[2].value))
> -	    {
> -	      delete_insns_since (last);
> -	      return expand_binop (mode, binoptab, op0, op1, NULL_RTX,
> -				   unsignedp, methods);
> -	    }
> -
> -	  emit_insn (pat);
> -	  return ops[0].value;
> +	  delete_insns_since (last);
> +	  return expand_binop (mode, binoptab, op0, op1, NULL_RTX,
> +			       unsignedp, methods);
>  	}
> +
> +      emit_insn (pat);
> +      return ops[0].value;
>      }
>    delete_insns_since (last);
>    return NULL_RTX;