Re: PING: PATCH [4/n]: Prepare x32: Permute the conversion and addition if one operand is a constant

[Paolo Bonzini <bonzini at gnu dot org>]

Ok, you removed ignore_address_wrap_around, so we're almost there.

On 07/28/2011 07:59 PM, H.J. Lu wrote:
> @@ -712,7 +715,16 @@ convert_modes (enum machine_mode mode, enum machine_mode oldmode, rtx x, int uns
>     if (GET_CODE (x) == SUBREG&&  SUBREG_PROMOTED_VAR_P (x)
>         &&  GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))>= GET_MODE_SIZE (mode)
>         &&  SUBREG_PROMOTED_UNSIGNED_P (x) == unsignedp)
> -    x = gen_lowpart (mode, x);
> +    {
> +      temp = rtl_hooks.gen_lowpart_no_emit (mode, x);
> +      if (temp)
> +	x = temp;
> +      else
> +	{
> +	  gcc_assert (!no_emit);
> +	  x = gen_lowpart (mode, x);
> +	}
> +    }

+    {
+       /* gen_lowpart_no_emit should always succeed here.  */
+       x = rtl_hooks.gen_lowpart_no_emit (mode, x);
+    }

>     if (GET_MODE (x) != VOIDmode)
>       oldmode = GET_MODE (x);
> @@ -776,6 +788,10 @@ convert_modes (enum machine_mode mode, enum machine_mode oldmode, rtx x, int uns
>   	  return gen_int_mode (val, mode);
>   	}
>
> +      temp = rtl_hooks.gen_lowpart_no_emit (mode, x);
> +      if (temp)
> +	return temp;
> +      gcc_assert (!no_emit);
>         return gen_lowpart (mode, x);

Right now, gen_lowpart_no_emit will never return NULL, so these tests in 
convert_modes are dead.  Instead, please include in your patch mine at 
http://permalink.gmane.org/gmane.comp.gcc.patches/242085 and adjust as 
follows.

+      temp = rtl_hooks.gen_lowpart_no_emit (mode, x);
+      if (no_emit)
+	 return rtl_hooks.gen_lowpart_no_emit (mode, x);
+      else
+        return gen_lowpart (mode, x);

>       }

If it does not work, PLEASE say why instead of posting another "updated 
patch".

Paolo