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Re: [RFC] Fix PR tree-optimization/34036

From: Eric Botcazou <ebotcazou at libertysurf dot fr>
To: "Richard Guenther" <richard dot guenther at gmail dot com>
Cc: gcc-patches at gcc dot gnu dot org, "Hans-Peter Nilsson" <hans-peter dot nilsson at axis dot com>, "Mark Mitchell" <mark at codesourcery dot com>
Date: Mon, 19 Nov 2007 12:17:17 +0100
Subject: Re: [RFC] Fix PR tree-optimization/34036
References: <200711190912.lAJ9CCfg025667@ignucius.se.axis.com> <200711191107.47229.ebotcazou@libertysurf.fr> <84fc9c000711190224v452773aag3a1ceb49ad37e52a@mail.gmail.com>

> So in fact we now changed the semantics of -funsafe-math-optimizations.

Sort of.  You said that re-association may introduce or remove traps so 
-fu-m-o has never enforced trapping arithmetics, eventhough -ftrapping-math 
was enabled.

> W/o -fassociative-math all its optimizations were in unsafe-math, so I think
> we should retain them there. 

Could you clarify a little? :-)

> So, apart from adjusting the testcases (I think it's enough to fix those
> that we run into problems with - but if you have time to audit the rest,
> that would be great), this change (enabling -fno-trapping-math for -fu-m-o)
> deserves a changes.html entry.  Can you please add one?

OK, will do.

-- 
Eric Botcazou

Follow-Ups:
- Re: [RFC] Fix PR tree-optimization/34036
  - From: Richard Guenther

References:
- Re: [RFC] Fix PR tree-optimization/34036
  - From: Hans-Peter Nilsson
- Re: [RFC] Fix PR tree-optimization/34036
  - From: Eric Botcazou
- Re: [RFC] Fix PR tree-optimization/34036
  - From: Richard Guenther

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