internal/bytealg: optimize indexbyte function for ppc64le/power9
Added specific code For POWER9 that does not need prealignment prior
to load vector. Optimized vector loop to jump out as soon as there is
a match instead of accumulating matches for 4 indices and then processing
the same. For small input size 10, the caller function dominates
performance.
name old time/op new time/op delta
IndexByte/10 9.20ns ± 0% 10.40ns ± 0% +13.08%
IndexByte/32 9.77ns ± 0% 9.20ns ± 0% -5.84%
IndexByte/4K 171ns ± 0% 136ns ± 0% -20.51%
IndexByte/4M 154µs ± 0% 126µs ± 0% -17.92%
IndexByte/64M 2.48ms ± 0% 2.03ms ± 0% -18.27%
IndexAnyASCII/1:32 10.2ns ± 1% 9.2ns ± 0% -9.19%
IndexAnyASCII/1:64 11.3ns ± 0% 10.1ns ± 0% -11.29%
IndexAnyUTF8/1:64 11.4ns ± 0% 9.8ns ± 0% -13.73%
IndexAnyUTF8/16:64 156ns ± 1% 131ns ± 0% -16.23%
IndexAnyUTF8/256:64 2.27µs ± 0% 1.86µs ± 0% -18.03%
LastIndexAnyUTF8/1:64 11.8ns ± 0% 10.5ns ± 0% -10.81%
LastIndexAnyUTF8/16:64 165ns ±11% 132ns ± 0% -19.75%
LastIndexAnyUTF8/256:2 1.68µs ± 0% 1.44µs ± 0% -14.33%
LastIndexAnyUTF8/256:4 1.68µs ± 0% 1.49µs ± 0% -11.10%
LastIndexAnyUTF8/256:8 1.68µs ± 0% 1.50µs ± 0% -11.05%
LastIndexAnyUTF8/256:64 2.30µs ± 0% 1.90µs ± 0% -17.56%
Change-Id: I3d2550bdfdea38fece2da9960bbe62fe6cb1840c
Reviewed-on: https://go-review.googlesource.com/c/go/+/397614
Reviewed-by: Paul Murphy <murp@ibm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Archana Ravindar <aravind5@in.ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>