tree c9f70493d6bdb44a11231b92e9b06fc08b8db82d
parent 8729675da7e470dd015dd541f25ee77a9884f210
author Damien Neil <dneil@google.com> 1579910420 -0800
committer Damien Neil <dneil@google.com> 1580077385 +0000

internal/impl: inline small tag decoding

Inline varint decoding of small (1- and 2-byte) field tags in the
fast-path unmarshaler.

name                             old time/op  new time/op  delta
EmptyMessage/Wire/Unmarshal      40.6ns ± 1%  40.2ns ± 1%   -1.02%  (p=0.000 n=37+35)
EmptyMessage/Wire/Unmarshal-12   6.77ns ± 2%  7.13ns ± 5%   +5.32%  (p=0.000 n=37+37)
RepeatedInt32/Wire/Unmarshal     9.46µs ± 1%  6.57µs ± 1%  -30.56%  (p=0.000 n=38+39)
RepeatedInt32/Wire/Unmarshal-12  1.50µs ± 2%  1.05µs ± 2%  -30.00%  (p=0.000 n=39+37)
Required/Wire/Unmarshal           371ns ± 1%   258ns ± 1%  -30.44%  (p=0.000 n=38+32)
Required/Wire/Unmarshal-12       60.3ns ± 1%  44.3ns ± 2%  -26.45%  (p=0.000 n=38+36)

Change-Id: Ie80415dea8cb6b840eafa52f0572046a1910a9b1
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/216419
Reviewed-by: Joe Tsai <joetsai@google.com>