[ECOS] Enabling -O2 option of GCC]

Jonathan Larmour jlarmour@redhat.com
Thu Dec 13 06:02:00 GMT 2001


David Webster wrote:
> 
> An efficient memcpy is something that is processor specific (sometimes
> even target specific depending on memory widths etc) - so it's most
> sensible for eCos infra to supply a generic memcpy that's adequate and
> let the compiler/processor/target override it with its own if necessary.

Yes it should, and there's no good reason it hasn't except for lack of
time, and in the past a certain amount of disagreement about where such
optimized standard functions should live. The latter problem is greatly
helped now that the isoinfra package exists.

You can get an efficient hand-written assembler memcpy for ARM from newlib
for example. The same is true for most other architectures. We can use
these versions freely in eCos.

http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/newlib/libc/machine/xscale/memcpy.c?rev=1.1&content-type=text/x-cvsweb-markup&cvsroot=src

( yes I know it says xscale, but it's ARM too really - it's just that
xscale.h defines away PRELOADSTR).

Jifl
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