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| Message-ID | <4F342DBE.9030600@loria.fr> (permalink) |
|---|---|
| Date | 2012-02-09 21:34 +0100 |
| From | Jens Gustedt <jens.gustedt@loria.fr> |
| Newsgroups | comp.lang.c |
| Subject | Re: a = b or memset/cpy? |
| References | <abb85a15-f68c-4e2f-8985-fe8b4945aca0@t8g2000yqg.googlegroups.com> <jgsdla$ol5$1@dont-email.me> |
| Organization | Guest of ProXad - France |
Am 02/08/2012 12:58 AM, schrieb Shao Miller:
> On 2/7/2012 12:02, nroberts wrote:
> I'm not sure how you could gain anything unless the call to 'memset'
> actually translates differently than a '= { 0 };'-style initializer.
The gain is in the knowledge of the optimizer. If you have a memset
initialization it is difficult (but not impossible) for the optimizer
to keep track of initializations. If it knows of initializations and
it encounters an assignment of a field of the struct before it is ever
read, the optimizer is allowed to omit the initialization. Modern
optimizers can be quite good in tracking individual struct or array
members.
Jens
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a = b or memset/cpy? nroberts <roberts.noah@gmail.com> - 2012-02-07 09:02 -0800
Re: a = b or memset/cpy? Jens Gustedt <jens.gustedt@loria.fr> - 2012-02-07 18:41 +0100
Re: a = b or memset/cpy? James Kuyper <jameskuyper@verizon.net> - 2012-02-07 13:40 -0500
Re: a = b or memset/cpy? Jens Gustedt <jens.gustedt@loria.fr> - 2012-02-07 20:09 +0100
Re: a = b or memset/cpy? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-02-07 11:37 -0800
Re: a = b or memset/cpy? Shao Miller <sha0.miller@gmail.com> - 2012-02-07 18:35 -0500
Re: a = b or memset/cpy? nroberts <roberts.noah@gmail.com> - 2012-02-07 11:07 -0800
Re: a = b or memset/cpy? blp@cs.stanford.edu (Ben Pfaff) - 2012-02-07 11:14 -0800
Re: a = b or memset/cpy? nroberts <roberts.noah@gmail.com> - 2012-02-07 11:41 -0800
Re: a = b or memset/cpy? Shao Miller <sha0.miller@gmail.com> - 2012-02-07 18:39 -0500
Re: a = b or memset/cpy? "Scott Fluhrer" <sfluhrer@ix.netcom.com> - 2012-02-07 14:14 -0500
Re: a = b or memset/cpy? Shao Miller <sha0.miller@gmail.com> - 2012-02-07 18:58 -0500
Re: a = b or memset/cpy? Shao Miller <sha0.miller@gmail.com> - 2012-02-07 21:58 -0500
Re: a = b or memset/cpy? Jens Gustedt <jens.gustedt@loria.fr> - 2012-02-09 21:34 +0100
Re: a = b or memset/cpy? Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-07 20:34 -0500
Re: a = b or memset/cpy? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-02-08 18:43 +0000
Re: a = b or memset/cpy? jgk@panix.com (Joe keane) - 2012-02-08 20:05 +0000
Re: a = b or memset/cpy? Ian Collins <ian-news@hotmail.com> - 2012-02-09 09:18 +1300
Re: a = b or memset/cpy? Tim Prince <tim@nospamcomputer.org> - 2012-02-14 08:30 -0500
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