Marvell EBU 32-bit performance benchmarks (VFPv3-D16 vs NEON builds, Turris Omnia).

[Rui Salvaterra]

Hi, guys,

So, last meeting I proposed splitting the 32-bit mvebu target in
vfpv3-d16 and neon subtargets. It seems this subject comes up every
couple of years, or so. This time I hope to show solid evidence on why
it would be an exercise in futility, closing the matter once and for
all. In order to do so, I tested the performance of openssl speed (10
seconds time limit), cryptsetup benchmark and iperf3 over WireGuard.
Here are the results for each build:

VFPv3-D16:
https://paste.debian.net/1216262/

NEON:
https://paste.debian.net/1216261/

These are master builds from my stmvebu branch, running Linux 5.10.75.
The configuration is custom, but each build differs only in the
CPU_SUBTYPE (vfpv3-d16 vs neon).

Cheers,
Rui