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Re: Proposal for merging scalar-storage-order branch into mainline
- From: Richard Biener <richard dot guenther at gmail dot com>
- To: Eric Botcazou <ebotcazou at adacore dot com>
- Cc: GCC Development <gcc at gcc dot gnu dot org>
- Date: Tue, 9 Jun 2015 13:53:29 +0200
- Subject: Re: Proposal for merging scalar-storage-order branch into mainline
- Authentication-results: sourceware.org; auth=none
- References: <2354857 dot 0uXrE6NL1R at polaris> <24307404 dot yEd3bIJVu1 at polaris> <CAFiYyc3UYWMKCE=qRwY=iPjtscB3o3nyQBLDBjLrnX4d5NKNvg at mail dot gmail dot com> <5929917 dot 788V8UTWHt at polaris>
On Tue, Jun 9, 2015 at 1:12 PM, Eric Botcazou <ebotcazou@adacore.com> wrote:
>> Yes, but I'd expect them to be optimized away (well, hopefully).
>
> OK, but you cannot reasonably expose everything in GENERIC/GIMPLE, for example
> the mask-and-shift operations to extract bitfields in reverse SSO, only the
> RTL expander has the (quite complex) logic and I doubt you want to teach the
> GIMPLE optimizers about this low-level mess.
Why would you want to support this on bitfields ... (/me runs away).
>> Anwyay, and I thought use of the feature would be rare so that "every load
>> and store" is still very few?
>
> Experience has shown that, when users start to use it, they use it extensively
> (too extensively if you ask me) so the implementation cannot be too dumb.
:/
> --
> Eric Botcazou