[Bug target/88271] Omit test instruction after add

[bugzilla@poradnik-webmastera.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88271

--- Comment #5 from Daniel Fruzynski <bugzilla@poradnik-webmastera.com> ---
How to use perf? I did not have change to use it yet, I usually use time
command or callgrind.

I have run my app compiled with AVX2 instructions on Xeon E5-2683 v3, CentOS
7.6, on idle CPU. I run it 3 times for both versions (w/ and w/o test
instructions). Here are results:

With test: Average 246,3 ms, StdDev 0,198
W/o test: Average 244,013ms, StdDev 0,043

Version with test is 0,94% slower - this is result which I expected.