public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug ipa/93385] [10 Regression] wrong code with u128 modulo at -O2 -fno-dce -fno-ipa-cp -fno-tree-dce
Date: Fri, 17 Apr 2020 12:08:44 +0000	[thread overview]
Message-ID: <bug-93385-4-t5iW77GHbS@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-93385-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93385

--- Comment #19 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Martin Jambor from comment #17)
> Created attachment 48302 [details]
> Untested fix
> 
> I'm playing with this - only very mildly tested - fix.

Ugh.

I was thinking of altering the parameter setup for cloning/inlining
so that it maps a removed parameter [SSA_NAME] not to a new
uninitialized variable/default-def but to error_mark_node and then
either scanning the function for those, propagating & DCEing on the
fly, or, during cloning/inlining seed a worklist whenever we map
something to error_mark_node.

The advantage is that we're leaving the IL in a clearly invalid state
in case one of those slips through and that the call case you handle
should handle itself by followup IPA transforms.

Another option is to track a set of removed SSA names in the original
and whenever we encounter an original stmt using that during the copying
operation elide the copy or transform it.  IIRC there's already a stmt
transform hook for IPA that could eventually be used for this approach\
(the modify_gimple_stmt hook), but it alreayd gets the copied stmts so
all defs have been cloned and the safety the error_mark_node approach
would bring is lost.

  parent reply	other threads:[~2020-04-17 12:08 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-93385-4@http.gcc.gnu.org/bugzilla/>
2020-03-15 11:58 ` jakub at gcc dot gnu.org
2020-04-09  9:25 ` rguenth at gcc dot gnu.org
2020-04-17 11:50 ` jamborm at gcc dot gnu.org
2020-04-17 12:06 ` jakub at gcc dot gnu.org
2020-04-17 12:08 ` rguenth at gcc dot gnu.org [this message]
2020-04-17 12:09 ` jakub at gcc dot gnu.org
2020-04-17 12:16 ` rguenther at suse dot de
2020-04-17 13:41 ` jamborm at gcc dot gnu.org
2020-04-17 13:53 ` jakub at gcc dot gnu.org
2020-04-17 14:00 ` rguenther at suse dot de
2020-04-17 14:00 ` jamborm at gcc dot gnu.org
2020-04-17 14:11 ` jakub at gcc dot gnu.org
2020-04-17 14:23 ` jakub at gcc dot gnu.org
2020-04-20  8:14 ` rguenther at suse dot de
2020-04-20  9:06 ` jakub at gcc dot gnu.org
2020-04-20 21:02 ` jamborm at gcc dot gnu.org
2020-04-21 10:34 ` rguenth at gcc dot gnu.org
2020-04-21 13:00 ` jakub at gcc dot gnu.org
2020-05-04 12:03 ` [Bug ipa/93385] [10/11 " cvs-commit at gcc dot gnu.org
2020-05-07 11:56 ` jakub at gcc dot gnu.org
2020-05-28 12:33 ` jamborm at gcc dot gnu.org
2020-06-08 18:18 ` jamborm at gcc dot gnu.org
2020-07-23  6:51 ` rguenth at gcc dot gnu.org
2020-07-27 15:04 ` jamborm at gcc dot gnu.org
2020-11-26 12:01 ` jamborm at gcc dot gnu.org
2021-01-21 15:18 ` jakub at gcc dot gnu.org
2021-03-12 12:51 ` jamborm at gcc dot gnu.org
2021-03-30 13:12 ` jamborm at gcc dot gnu.org
2021-04-08 12:02 ` rguenth at gcc dot gnu.org
2021-04-27 13:35 ` [Bug ipa/93385] [10/11/12 " jamborm at gcc dot gnu.org
2021-05-12 11:40 ` jamborm at gcc dot gnu.org
2021-06-28 16:28 ` cvs-commit at gcc dot gnu.org
2021-06-28 16:28 ` cvs-commit at gcc dot gnu.org
2021-06-28 17:30 ` [Bug ipa/93385] [10/11 " jamborm at gcc dot gnu.org
2021-11-04 17:09 ` cvs-commit at gcc dot gnu.org
2022-06-28 10:39 ` jakub at gcc dot gnu.org
2023-07-07 10:36 ` [Bug ipa/93385] [11 " rguenth at gcc dot gnu.org
2023-07-14 20:09 ` pinskia at gcc dot gnu.org
2023-07-29  8:07 ` pinskia at gcc dot gnu.org
2023-07-29  9:16 ` xry111 at gcc dot gnu.org
2023-07-29  9:43 ` rguenther at suse dot de

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-93385-4-t5iW77GHbS@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).