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Re: No TBAA before ptr_derefs_may_alias_p?
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Bingfeng Mei <bmei at broadcom dot com>
- Cc: Richard Biener <rguenther at suse dot de>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Mon, 3 Feb 2014 10:59:38 +0100
- Subject: Re: No TBAA before ptr_derefs_may_alias_p?
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- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Mon, Feb 03, 2014 at 09:51:01AM +0000, Bingfeng Mei wrote:
> If it is just for C++ placement new, why don't implement it as a lang_hook.
> Now other languages such as C have to be made conservative and produce worse
Even in C++ code you don't use placement new that often, so e.g. by having
the placement new explicit through some special GIMPLE statement in the IL,
you could e.g. just look if a particular function or loop contains any
placement new stmts (cached in struct function and loop?) and use TBAA if
it isn't there.