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Mail Archives: djgpp/1998/03/28/13:40:35

Date: Sat, 28 Mar 1998 10:39:17 -0800 (PST)
Message-Id: <199803281839.KAA16466@adit.ap.net>
Mime-Version: 1.0
To: waldroni AT lr DOT net, djgpp AT delorie DOT com
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: 16 or 32 bit transfers

At 02:51  3/27/1998 -0500, Isaac Waldron wrote:
>Is it possible to transfer data from a drawbuffer to video memory
>without using memcpy, which uses 8 bit transfers?  I would like to
>transfer it in 16 or even 32 bit chunks if possible.  Also, can I fill a
>drawbuffer using 16 or 32 bit fills instead of the 8 bits that memset
>uses?

`memcpy' does NOT use 8 bit transfers. It's automagically inlined by GCC,
and expands mainly to a `rep; movsl' (32-bit transfers). `memset' is not
inlined, but also uses 32-bit transfers as much as possible. (See the source
if you don't believe me; `src/libc/ansi/string/memset.S'.)

Nate Eldredge
eldredge AT ap DOT net



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