erifan01 de28555c0b internal/bytealg: optimize Equal on arm64 ... Currently the 16-byte loop chunk16_loop is implemented with NEON instructions LD1, VMOV and VCMEQ. Using scalar instructions LDP and CMP to achieve this loop can reduce the number of clock cycles. For cases where the length of strings are between 4 to 15 bytes, loading the last 8 or 4 bytes at a time to reduce the number of comparisons. Benchmarks: name old time/op new time/op delta Equal/0-8 5.51ns ± 0% 5.84ns ±14% ~ (p=0.246 n=7+8) Equal/1-8 10.5ns ± 0% 10.5ns ± 0% ~ (all equal) Equal/6-8 14.0ns ± 0% 12.5ns ± 0% -10.71% (p=0.000 n=8+8) Equal/9-8 13.5ns ± 0% 12.5ns ± 0% -7.41% (p=0.000 n=8+8) Equal/15-8 15.5ns ± 0% 12.5ns ± 0% -19.35% (p=0.000 n=8+8) Equal/16-8 14.0ns ± 0% 13.0ns ± 0% -7.14% (p=0.000 n=8+8) Equal/20-8 16.5ns ± 0% 16.0ns ± 0% -3.03% (p=0.000 n=8+8) Equal/32-8 16.5ns ± 0% 15.3ns ± 0% -7.27% (p=0.000 n=8+8) Equal/4K-8 552ns ± 0% 553ns ± 0% ~ (p=0.315 n=8+8) Equal/4M-8 1.13ms ±23% 1.20ms ±27% ~ (p=0.442 n=8+8) Equal/64M-8 32.9ms ± 0% 32.6ms ± 0% -1.15% (p=0.000 n=8+8) CompareBytesEqual-8 12.0ns ± 0% 12.0ns ± 0% ~ (all equal) Change-Id: If317ecdcc98e31883d37fd7d42b113b548c5bd2a Reviewed-on: https://go-review.googlesource.com/112496 Reviewed-by: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com>		2018-09-12 19:56:55 +00:00
..
bytealg	internal/bytealg: optimize Equal on arm64	2018-09-12 19:56:55 +00:00
cpu	runtime: replace sys.CacheLineSize by corresponding internal/cpu const and vars	2018-08-24 18:28:25 +00:00
nettrace
poll	internal/poll: handle zero-byte write in FD.WriteTo	2018-09-09 04:42:15 +00:00
race
singleflight	net: don't let cancelation of a DNS lookup affect another lookup	2018-03-16 13:39:38 +00:00
syscall	internal/syscall/unix: remove unnecessary empty.s	2018-08-28 14:05:21 +00:00
testenv	all: skip unsupported tests for js/wasm	2018-04-30 19:39:18 +00:00
testlog
trace	all: fix typos detected by github.com/client9/misspell	2018-08-23 15:54:07 +00:00