public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Eric Botcazou <ebotcazou@adacore.com>
To: Richard Guenther <rguenther@suse.de>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Cleanup expand_shift
Date: Wed, 04 May 2011 15:34:00 -0000	[thread overview]
Message-ID: <201105041732.49116.ebotcazou@adacore.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1105031625230.810@zhemvz.fhfr.qr>

> 2011-05-03  Richard Guenther  <rguenther@suse.de>
>
> 	* expmed.c (expand_variable_shift): Rename to ...
> 	(expand_shift_1): ... this.  Take an expanded shift amount.
> 	For rotates recurse directly not building trees for the shift amount.
> 	(expand_variable_shift): Wrap around expand_shift_1.
> 	(expand_shift): Adjust.

Looks OK on principle, but...

> --- 2140,2161 ----
>   		 code below.  */
>
>   	      rtx subtarget = target == shifted ? 0 : target;
> ! 	      rtx new_amount, other_amount;
>   	      rtx temp1;
> !
> ! 	      new_amount = amount;
>   	      other_amount
> ! 		= simplify_gen_binary (MINUS, GET_MODE (amount),
> ! 				       GEN_INT (GET_MODE_BITSIZE (mode)),
> ! 				       amount);

... why going back to AMOUNT?  The old code uses OP1, which can be different 
from AMOUNT if SHIFT_COUNT_TRUNCATED is nonzero.

-- 
Eric Botcazou

  reply	other threads:[~2011-05-04 15:33 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-03 14:42 Richard Guenther
2011-05-04 15:34 ` Eric Botcazou [this message]
2011-05-04 15:43   ` Richard Guenther
2011-05-04 16:09     ` Eric Botcazou
2011-05-04 16:10       ` Richard Guenther
2011-05-05 12:38         ` Richard Guenther
2011-05-06  4:50           ` Hans-Peter Nilsson
2011-05-06  9:39             ` Richard Guenther
2011-05-06 21:52               ` Eric Botcazou

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=201105041732.49116.ebotcazou@adacore.com \
    --to=ebotcazou@adacore.com \
    --cc=gcc-patches@gcc.gnu.org \
    --cc=rguenther@suse.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).