memcpy performance
Jonathan Larmour
jlarmour@cygnus.co.uk
Tue Dec 9 08:48:00 GMT 1997
Joel Sherrill wrote:
>
> An RTEMS user has noticed that the performance of the RTEMS message
> queue routines is bound by our use of newlib's memcpy routine. The
> current implementation uses a byte-by-byte copy.
>
> What would it take to get a better generic implementation? Is there one
> laying around which could be used instead? I remember the old GNU/960
> version did some alignment and then copied 16-bytes at a time.
The current newlib implementation has this already in
libc/string/memcpy.c
et al. There is a #define PREFER_SIZE_OVER_SPEED which will use the
byte-by-byte copy if it is defined, otherwise it will use the 16-byte at
a time one.
Perhaps he has PREFER_SIZE_OVER_SPEED set?
Jonathan L.
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