| commit | ecc3f5112ebaf23c4b1ac4c5eedfa406d82ecc9a | [log] [tgz] |
|---|---|---|
| author | Jonathan Swinney <jswinney@amazon.com> | Wed Nov 04 16:18:23 2020 +0000 |
| committer | Cherry Zhang <cherryyz@google.com> | Thu Nov 05 23:21:33 2020 +0000 |
| tree | f73baf58f3df5fcdcec20b65e3223260f14472ea | |
| parent | 8e5778ed70ec3d371615a663520a586745fb7bee [diff] |
cmd/compile: improve atomic swap intrinsics on arm64 ARMv8.1 has added new instructions for atomic memory operations. This change builds on the previous change which added support for atomic add, 0a7ac93c27c9ade79fe0f66ae0bb81484c241ae5, to include similar support for atomic-compare-and-swap, atomic-swap, atomic-or, and atomic-and intrinsics. Since the new instructions are not guaranteed to be present, we guard their usages with a branch on a CPU feature. Peformance on an ARMv8.1 machine: name old time/op new time/op delta CompareAndSwap-16 37.9ns ±16% 24.1ns ± 4% -36.44% (p=0.000 n=10+9) CompareAndSwap64-16 38.6ns ±15% 24.1ns ± 3% -37.47% (p=0.000 n=10+10) name old time/op new time/op delta Swap-16 46.9ns ±32% 12.5ns ± 6% -73.40% (p=0.000 n=10+10) Swap64-16 53.4ns ± 1% 12.5ns ± 6% -76.56% (p=0.000 n=10+10) name old time/op new time/op delta Or8-16 8.81ns ± 0% 5.61ns ± 0% -36.32% (p=0.000 n=10+10) Or-16 7.21ns ± 0% 5.61ns ± 0% -22.19% (p=0.000 n=10+10) Or8Parallel-16 59.8ns ± 3% 12.5ns ± 2% -79.10% (p=0.000 n=10+10) OrParallel-16 51.7ns ± 3% 12.5ns ± 2% -75.84% (p=0.000 n=10+10) name old time/op new time/op delta And8-16 8.81ns ± 0% 5.61ns ± 0% -36.32% (p=0.000 n=10+10) And-16 7.21ns ± 0% 5.61ns ± 0% -22.19% (p=0.000 n=10+10) And8Parallel-16 59.1ns ± 6% 12.8ns ± 3% -78.33% (p=0.000 n=10+10) AndParallel-16 51.4ns ± 7% 12.8ns ± 3% -75.03% (p=0.000 n=10+10) Performance on an ARMv8.0 machine (no atomics instructions): name old time/op new time/op delta CompareAndSwap-16 61.3ns ± 0% 62.4ns ± 0% +1.70% (p=0.000 n=8+9) CompareAndSwap64-16 62.0ns ± 3% 61.3ns ± 2% ~ (p=0.093 n=10+10) name old time/op new time/op delta Swap-16 127ns ± 2% 131ns ± 2% +2.91% (p=0.001 n=10+10) Swap64-16 128ns ± 1% 131ns ± 2% +2.43% (p=0.001 n=10+10) name old time/op new time/op delta Or8-16 14.9ns ± 0% 15.3ns ± 0% +2.68% (p=0.000 n=10+10) Or-16 11.8ns ± 0% 12.3ns ± 0% +4.24% (p=0.000 n=10+10) Or8Parallel-16 137ns ± 1% 144ns ± 1% +4.97% (p=0.000 n=10+10) OrParallel-16 128ns ± 1% 136ns ± 1% +6.34% (p=0.000 n=10+10) name old time/op new time/op delta And8-16 14.9ns ± 0% 15.3ns ± 0% +2.68% (p=0.000 n=10+10) And-16 11.8ns ± 0% 12.3ns ± 0% +4.24% (p=0.000 n=10+10) And8Parallel-16 134ns ± 2% 141ns ± 1% +5.29% (p=0.000 n=10+10) AndParallel-16 125ns ± 2% 134ns ± 1% +7.10% (p=0.000 n=10+10) Fixes #39304 Change-Id: Idaca68701d4751650be6b4bedca3d57f51571712 Reviewed-on: https://go-review.googlesource.com/c/go/+/234217 Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Trust: fannie zhang <Fannie.Zhang@arm.com>
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