Re: toolchain/60289 (NetBSD 11 gcc mis-optimises some NULL checks)

["Manuel Bouyer via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR toolchain/60289; it has been noted by GNATS.

From: Manuel Bouyer <manuel.bouyer%lip6.fr@localhost>
To: RVP <rvp%SDF.ORG@localhost>
Cc: gnats-bugs%netbsd.org@localhost
Subject: Re: toolchain/60289 (NetBSD 11 gcc mis-optimises some NULL checks)
Date: Sun, 24 May 2026 13:42:46 +0200

 On Sun, May 24, 2026 at 09:10:03AM +0000, RVP wrote:
 > On Sun, 24 May 2026, Manuel Bouyer wrote:
 > 
 > > A quick search showed other projects (bind, openjdk) running into this
 > > 
 > 
 > This is an old issue, and the gcc devs' response to all the howling on the
 > Linux side was "Will not fix".
 > 
 > https://lwn.net/Articles/342330/
 > https://lwn.net/Articles/342420/
 
 OK, but both articles mention -fno-delete-null-pointer-checks to deal with it.
 But in the specific case this PR is about, -fno-delete-null-pointer-checks
 doens't prevent the optimisation from removing the NULL pointer
 check. I think this is a bug in gcc, and none of the article above
 mention this issue (and I couldn't find a gcc bug report about it either).
 
 -- 
 Manuel Bouyer, LIP6, Sorbonne Université.           Manuel.Bouyer%lip6.fr@localhost
      NetBSD: 26 ans d'experience feront toujours la difference
 --