internal/runtime/maps: return after fatal to help register allocator
Seems simple, but putting the return after fatal ensures that at the
point of the small group loop, no call has happened so the key is
still in a register. This ensures that we don't have to restore the
key from the stack before the comparison on each iteration. That gets
rid of a load from the inner loop.
name old time/op new time/op delta
MapAccessHit/Key=int64/Elem=int64/len=6-8 4.01ns ± 6% 3.85ns ± 3% -3.92% (p=0.001 n=10+10)
Change-Id: Ia23ac48e6c5522be88f7d9be0ff3489b2dfc52fc
Reviewed-on: https://go-review.googlesource.com/c/go/+/624255 Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@google.com>