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Re: [PATCH][combine][1/2] Try to simplify before substituting
- From: Segher Boessenkool <segher at kernel dot crashing dot org>
- To: Kyrill Tkachov <kyrylo dot tkachov at arm dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, Andrew Pinski <apinski at cavium dot com>
- Date: Thu, 16 Jul 2015 13:28:01 -0500
- Subject: Re: [PATCH][combine][1/2] Try to simplify before substituting
- Authentication-results: sourceware.org; auth=none
- References: <55A7CCDA dot 8050203 at arm dot com> <20150716181306 dot GA8497 at gate dot crashing dot org> <55A7F552 dot 9030003 at arm dot com>
On Thu, Jul 16, 2015 at 07:17:54PM +0100, Kyrill Tkachov wrote:
> >If you always want to simplify first, does it work to move this whole big
> >block behind the simplify just following it? Or do you want to simplify
> >after the transform as well?
>
> You mean move this hunk outside the "if (BINARY_P (x)...)" block it's in?
> I think it would work, but I'm not sure if it would affect other cases.
> I was also conscious that simplify_rtx might not be a cheap function to call
> so frequently (or is it? I didn't profile it), so I tried to avoid calling
> it unless I need for the transformation in question here.
I mean move the whole "if (BINARY_P ..." block to after the existing
simplify calls, to just before the "First see if we can apply" comment,
and not do a new simplify_rtx call at all. Does that work?
Which brings the question why it wasn't there in the first place, hrm.
Segher