This requires changes to the Go toolchain.
The changes are upstream at https://golang.org/cl/320929.
They haven't been pulled into our fork yet.
No need to allocate new iteration scratch values for every map.
name old time/op new time/op delta
Hash-8 13.6µs ± 0% 13.5µs ± 0% -1.01% (p=0.008 n=5+5)
HashMapAcyclic-8 21.2µs ± 1% 21.1µs ± 2% ~ (p=0.310 n=5+5)
name old alloc/op new alloc/op delta
Hash-8 1.58kB ± 0% 1.46kB ± 0% -7.60% (p=0.008 n=5+5)
HashMapAcyclic-8 152B ± 0% 128B ± 0% -15.79% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
Hash-8 49.0 ± 0% 43.0 ± 0% -12.24% (p=0.008 n=5+5)
HashMapAcyclic-8 4.00 ± 0% 2.00 ± 0% -50.00% (p=0.008 n=5+5)
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
09afb8e35b