public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "wf831130 at sina dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/101076] RTL Combine pass won't generate sign_extnd RTX in some senario
Date: Tue, 15 Jun 2021 06:53:40 +0000	[thread overview]
Message-ID: <bug-101076-4-fsT7Sl6sWQ@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-101076-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101076

--- Comment #4 from Coco Wang <wf831130 at sina dot com> ---
(In reply to Andrew Pinski from comment #3)
> This sounds like a rsicv backend issue really ...

I think the key is the subreg, the reason why x86_64 and aarch64 have no
problems is that subreg does not appear in RTL.

The code of this part is not right
if (!OBJECT_P (lhs)
          && ! (GET_CODE (lhs) == SUBREG
                && (OBJECT_P (SUBREG_REG (lhs))))
          && CONST_INT_P (rhs)
          && INTVAL (rhs) >= 0
          && INTVAL (rhs) < HOST_BITS_PER_WIDE_INT
          && INTVAL (rhs) < mode_width
          && (new_rtx = extract_left_shift (mode, lhs, INTVAL (rhs))) != 0)
        new_rtx = make_extraction (mode, make_compound_operation (new_rtx,
                                                                  next_code),
                                   0, NULL_RTX, mode_width - INTVAL (rhs),
                                   code == LSHIFTRT, 0, in_code == COMPARE);

  parent reply	other threads:[~2021-06-15  6:53 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-15  3:37 [Bug rtl-optimization/101076] New: " wf831130 at sina dot com
2021-06-15  6:14 ` [Bug rtl-optimization/101076] " pinskia at gcc dot gnu.org
2021-06-15  6:31 ` wf831130 at sina dot com
2021-06-15  6:41 ` pinskia at gcc dot gnu.org
2021-06-15  6:53 ` wf831130 at sina dot com [this message]
2021-06-15  7:01 ` pinskia at gcc dot gnu.org
2023-06-02  5:25 ` pinskia at gcc dot gnu.org

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=bug-101076-4-fsT7Sl6sWQ@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@gcc.gnu.org \
    /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).