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[RFC] Use simpler math functions when user selects -ffast-math
- From: OndÅej BÃlka <neleai at seznam dot cz>
- To: andrew dot n dot senkevich at gmail dot com
- Cc: libc-alpha at sourceware dot org
- Date: Wed, 12 Aug 2015 00:30:07 +0200
- Subject: [RFC] Use simpler math functions when user selects -ffast-math
- Authentication-results: sourceware.org; auth=none
Hi Andrew,
When I checked isfinite performance I noticed that for most math
functions wrapper is unnecessary when -ffinite-math-only is set from
-ffast-math as they evaluate to constant.
So if you are still interested at improving math library you could in
similar way as vector math add calls to say fast_sin, fast_cos... I don't
know how to make vectorizer also recognize these so I ask you.
Adding new symbols would allow to fix bug that due accuracy math
functions need to be very slow on some inputs. As with -ffast-math you
don't have to worry much about accuracy we could finally fix these bugs.
So what do you say?