On Sat, 2 Mar 2024 21:40:03 -0800
Stephen Hemminger <step...@networkplumber.org> wrote:
> On Sun, 3 Mar 2024 00:48:12 +0100
> Morten Brørup <m...@smartsharesystems.com> wrote:
>
> > When the rte_memcpy() size is 16, the same 16 bytes are copied twice.
> > In the case where the size is knownto be 16 at build tine, omit the
> > duplicate copy.
> >
> > Reduced the amount of effectively copy-pasted code by using #ifdef
> > inside functions instead of outside functions.
> >
> > Suggested-by: Stephen Hemminger <step...@networkplumber.org>
> > Signed-off-by: Morten Brørup <m...@smartsharesystems.com>
> > ---
>
> Looks good, let me see how it looks in goldbolt vs Gcc.
>
> One other issue is that for the non-constant case, rte_memcpy has an
> excessively
> large inline code footprint. That is one of the reasons Gcc doesn't always
> inline. For > 128 bytes, it really should be a function.
For size of 4,6,8,16, 32, 64, up to 128 Gcc inline and rte_memcpy match.
For size 128. It looks gcc is simpler.
rte_copy_addr:
vmovdqu ymm0, YMMWORD PTR [rsi]
vextracti128 XMMWORD PTR [rdi+16], ymm0, 0x1
vmovdqu XMMWORD PTR [rdi], xmm0
vmovdqu ymm0, YMMWORD PTR [rsi+32]
vextracti128 XMMWORD PTR [rdi+48], ymm0, 0x1
vmovdqu XMMWORD PTR [rdi+32], xmm0
vmovdqu ymm0, YMMWORD PTR [rsi+64]
vextracti128 XMMWORD PTR [rdi+80], ymm0, 0x1
vmovdqu XMMWORD PTR [rdi+64], xmm0
vmovdqu ymm0, YMMWORD PTR [rsi+96]
vextracti128 XMMWORD PTR [rdi+112], ymm0, 0x1
vmovdqu XMMWORD PTR [rdi+96], xmm0
vzeroupper
ret
copy_addr:
vmovdqu ymm0, YMMWORD PTR [rsi]
vmovdqu YMMWORD PTR [rdi], ymm0
vmovdqu ymm1, YMMWORD PTR [rsi+32]
vmovdqu YMMWORD PTR [rdi+32], ymm1
vmovdqu ymm2, YMMWORD PTR [rsi+64]
vmovdqu YMMWORD PTR [rdi+64], ymm2
vmovdqu ymm3, YMMWORD PTR [rsi+96]
vmovdqu YMMWORD PTR [rdi+96], ymm3
vzeroupper
ret
