This is the mail archive of the
mailing list for the GCC project.
Re: [PATCH] Fix DCE REG_LIBCALL note moving from noop move insns (PR rtl-optimization/33644)
- From: Eric Botcazou <ebotcazou at libertysurf dot fr>
- To: Kenneth Zadeck <zadeck at naturalbridge dot com>
- Cc: gcc-patches at gcc dot gnu dot org, Steven Bosscher <stevenb dot gcc at gmail dot com>, Daniel Berlin <dberlin at dberlin dot org>, Jakub Jelinek <jakub at redhat dot com>
- Date: Wed, 17 Oct 2007 21:17:35 +0200
- Subject: Re: [PATCH] Fix DCE REG_LIBCALL note moving from noop move insns (PR rtl-optimization/33644)
- References: <email@example.com> <4713B351.firstname.lastname@example.org>
> I think that when danny and i started this, it was not considered an
> option to remove libcall notes. I never understood the reason for them,
Libcalls notes make it possible for the optimizers to know that the libcall
sequence has no side-effects, i.e. that is only used for its return value.
See for example delete_trivially_dead_insns.