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| From | christian.bau@cbau.wanadoo.co.uk |
| Newsgroups | comp.compilers |
| Subject | Re: Compiler optimization and floating point operations |
| Date | Mon, 28 Oct 2013 15:50:07 -0700 (PDT) |
| Organization | Compilers Central |
| Lines | 8 |
| Sender | johnl@iecc.com |
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| Keywords | arithmetic, optimize |
| Posted-Date | 28 Oct 2013 18:51:53 EDT |
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> [I think you mean they're not associative. I don't know any situations > where a+b != b+a, but lots where a+(b+c) != (a+b)+c -John] Take fused multiply-add, and the expression a*b + c*d. It can be evaluated either as fma (a, b, c*d) or fma (c, d, a*b). It would seem natural that the code for a*b + c*d and for c*d + a*b would be different, with different results.
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Compiler optimization and floating point operations Abid <abidmuslim@gmail.com> - 2013-10-23 13:47 -0700
Re: Compiler optimization and floating point operations Cameron McInally <cameron.mcinally@nyu.edu> - 2013-10-23 22:55 -0400
Re: Compiler optimization and floating point operations glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-10-24 02:56 +0000
Re: Compiler optimization and floating point operations George Neuner <gneuner2@comcast.net> - 2013-10-24 07:41 -0400
Re: Compiler optimization and floating point operations Jean-Marc Bourguet <jm@bourguet.org> - 2013-10-24 15:51 +0200
Re: Compiler optimization and floating point operations "Steven G. Kargl" <sgk@troutmask.apl.washington.edu> - 2013-10-24 16:38 +0000
Re: Compiler optimization and floating point operations christian.bau@cbau.wanadoo.co.uk - 2013-10-28 15:54 -0700
Re: Compiler optimization and floating point operations George Neuner <gneuner2@comcast.net> - 2013-10-24 15:51 -0400
Re: Compiler optimization and floating point operations glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-10-24 20:21 +0000
Re: Compiler optimization and floating point operations christian.bau@cbau.wanadoo.co.uk - 2013-10-28 15:50 -0700
Re: Compiler optimization and floating point operations Cameron McInally <cameron.mcinally@nyu.edu> - 2013-10-28 20:41 -0400
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