tree 8402d3170fe39d5e0b0a2ae0e62c30eb58981739
parent 1e5987635cc8bf99e8a20d240da80bd6f0f793f7
author Archana R <aravind5@in.ibm.com> 1636528722 -0600
committer Lynn Boger <laboger@linux.vnet.ibm.com> 1650629558 +0000

internal/bytealg: optimize cmpbody for ppc64le/ppc64

Vectorize the cmpbody loop for bytes of size greater than or equal
to 32 on both POWER8(LE and BE) and POWER9(LE and BE) and improve
performance of smaller size compares

Performance improves for most sizes with this change on POWER8, 9
and POWER10. For the very small sizes (upto 8) the overhead of
calling function starts to impact performance.

POWER9:
name               old time/op  new time/op  delta
BytesCompare/1     4.60ns ± 0%  5.49ns ± 0%  +19.27%
BytesCompare/2     4.68ns ± 0%  5.46ns ± 0%  +16.71%
BytesCompare/4     6.58ns ± 0%  5.49ns ± 0%  -16.58%
BytesCompare/8     4.89ns ± 0%  5.46ns ± 0%  +11.64%
BytesCompare/16    5.21ns ± 0%  4.96ns ± 0%   -4.70%
BytesCompare/32    5.09ns ± 0%  4.98ns ± 0%   -2.14%
BytesCompare/64    6.40ns ± 0%  5.96ns ± 0%   -6.84%
BytesCompare/128   11.3ns ± 0%   8.1ns ± 0%  -28.09%
BytesCompare/256   15.1ns ± 0%  12.8ns ± 0%  -15.16%
BytesCompare/512   26.5ns ± 0%  23.3ns ± 5%  -12.03%
BytesCompare/1024  50.2ns ± 0%  41.6ns ± 2%  -17.01%
BytesCompare/2048  99.3ns ± 0%  86.5ns ± 0%  -12.88%

Change-Id: I24f93b2910591e6829ddd8509aa6eeaa6355c609
Reviewed-on: https://go-review.googlesource.com/c/go/+/362797
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Run-TryBot: Archana Ravindar <aravind5@in.ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>