cases: small copies of up to 16 bytes, medium copies of 17..96 bytes which are
fully unrolled. Large copies of more than 96 bytes align the destination and
use an unrolled loop processing 64 bytes per iteration. In order to share code
with memmove, small and medium copies read all data before writing, allowing
any kind of overlap. All memmoves except for the large backwards case fall
into memcpy for optimal performance. On a random copy test memcpy/memmove are
40% faster on Cortex-A57 and 28% on Cortex-A53.
* sysdeps/aarch64/memcpy.S (memcpy):
Rewrite of optimized memcpy and memmove.
* sysdeps/aarch64/memmove.S (memmove): Remove
memmove code (merged into memcpy.S).
This patch moves the AArch64 port to the main sysdeps hierarchy. The
move is essentially:
git mv ports/sysdeps/aarch64 sysdeps/aarch64
git mv ports/sysdeps/unix/sysv/linux/aarch64 sysdeps/unix/sysv/linux/aarch64
The README is updated and I've updated ChangeLog.aarch64 along the
lines of the ARM move. The AArch64 build has been tested to confirm
that there were no changes in objdump -dr output or the shared
objects.
Wilco Dijkstra
Joseph Myers
Marcus Shawcroft