Hi, I can not really reproduce your results. I rewrote your code to use the builtin benchmarking: http://sprunge.us/IfQc Giving, on my laptop:
BenchmarkAssertion-4 1000000000 2.89 ns/op BenchmarkAssertionOK-4 500000000 2.66 ns/op BenchmarkBare-4 1000000000 2.22 ns/op BenchmarkIface-4 50000000 30.0 ns/op BenchmarkReflect-4 200000000 9.74 ns/op Note, that a) yes, there is an overhead of the type-assertion, but b) it's pretty small, especially compared to the other things you're trying and c) it can be further reduced by using the two-value form (so that there is never a need to consider stack-unwinding). Overall, this smells like a micro-benchmark. I wouldn't worry too much about it until you have specific evidence that it's slowing down a real program. On Thu, Feb 2, 2017 at 9:40 AM, T L <tapir....@gmail.com> wrote: > Type assertion is even slower than reflect: https://play.golang.org/p/ > zvUTEKDfiL > > assert: count=33554432 time taken=499.061188ms > direct: count=33554432 time taken=14.981847ms > method: count=33554432 time taken=176.977503ms > reflect: count=33554432 time taken=383.905004ms > > On Thursday, February 2, 2017 at 4:25:05 PM UTC+8, T L wrote: > >> >> >> On Thursday, February 2, 2017 at 2:04:23 PM UTC+8, ChrisLu wrote: >>> >>> Go's type assertion seems quite slow. The added cost is too much if it >>> has to be in a tight loop. Here are the time taken on my laptop for the >>> following code. >>> >>> https://play.golang.org/p/cA96miTkx_ >>> >>> >>> chris$ time ./p >>> count=1073741824 time taken=7.899207181s >>> count=1073741824 time taken=300.601453ms >>> >>> real 0m8.205s >>> user 0m8.163s >>> sys 0m0.029s >>> >>> chris$ time luajit -e "count = 0 >>> > for i=1, 1024*1024*1024, 1 do count = count + 1 end >>> > print(count)" >>> 1073741824 >>> >>> real 0m0.900s >>> user 0m0.891s >>> sys 0m0.005s >>> >>> >>> >> Type assertion is even slower than call dynamic method: >> https://play.golang.org/p/jUrazcbB9h >> Some surprised. >> >> > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
