https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83252
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
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Keywords| |wrong-code
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Dmitry Babokin from comment #6)
> I'm not insisting on such functionality, as my bugs were always analysed and
> fixed in timely manner (unlike with other compilers). But I still think gcc
> would benefit from such mechanism a lot.
The problem with GCC (and sometimes other compilers) is latent bugs in passes
after where the change happened. A lot of the time for GCC, this has been
true. Especially when we are talking about GCC's RTL passes; some of which
date from the mid to late 1990s (e.g. combine). And even some of the RTL
passes don't have an option flag to enable/disable (e.g. combine).
Also there are other things like disabling the late VRP or another pass which
uses the VRP data that was not updated which causes the bug to show up.
Just a few examples of why this functionality is not very useful in GCC and
also it gets abused by some users of it to workaround a bug in one specific
version of GCC rather than reporting the bug :).
