Hi, On Tue, Oct 29, 2024 at 11:39:03AM +0200, Heikki Linnakangas wrote: > On 29/10/2024 09:54, Bertrand Drouvot wrote: > > > https://godbolt.org/z/x9hPWjheq. > > > > Yeah, I also think that's fine. Peter Smith did some testing in [1] > > comparing > > memcmp and simple loop checking (thanks Peter for the testing!): > > > > " > > Iterate 1000000 times... > > check zeros using loop -- elapsed=0.041196s > > check zeros using memcmp -- elapsed=0.016407s > > " > > > > So, in this test, the loop is 0.024789s longer means 0.024789s/1000000=24 > > Nanosecond > > slower per comparison (If my math is correct). > > I believe that test program is bogus. Look at the assembly code; the > compiler optimized away the loops.
Oh right. It looks like that moving the "scanf" within each loop "helps" and that both give pretty comparable results. Regards, -- Bertrand Drouvot PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com
