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 tree-optimization/42436] VRP should mark non-trapping integer divisions Date: Thu, 13 Jan 2022 07:13:02 +0000 [thread overview] Message-ID: <bug-42436-4-yyGWEgNByJ@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-42436-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42436 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |FIXED Status|NEW |RESOLVED --- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- I think this was trying to cover things like if (d != 0) tem = a / d; where the non-zero range of d on the division cannot be put in global ranges for its SSA name since that would be incorrect for uses not guarded by the condition. So it would ask for a new flag on GIMPLE statements to mark the division not trapping (like we have TREE_THIS_NOTRAP). Transforms like PRE or LIM that do code motion of course have to be careful to not move the stmt outside of the condition that made it not trapping - something which would be as hard to guarantee as computing the non-trappingness in the first place. So yes, the case that made me file this bug is fixed with global ranges. Let's close this bug since it's quite unspecific.
next prev parent reply other threads:[~2022-01-13 7:13 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <bug-42436-4@http.gcc.gnu.org/bugzilla/> 2022-01-12 16:14 ` amacleod at redhat dot com 2022-01-13 7:13 ` rguenth at gcc dot gnu.org [this message] 2009-12-19 19:41 [Bug tree-optimization/42436] New: " rguenth at gcc dot gnu dot org 2009-12-19 19:42 ` [Bug tree-optimization/42436] " rguenth at gcc dot gnu dot 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-42436-4-yyGWEgNByJ@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: linkBe 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).