https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71741
--- Comment #2 from Alex <cranon at yandex dot ru> --- At attachment There is no all sources of my program, you can find it here: https://github.com/mediev/inclined_well/tree/gcc_bug But, instead of my program, I ask you to try reproduce the simple example of code here: http://stackoverflow.com/questions/38172066/the-program-works-3-times-slower-compiled-with-g-5-3-1-than-the-same-program-c where just calculates sum(sin(x)/x) at cycle for. This sample are processed 2.5 time slower (at average) under libc-2.23, gcc 5.3.1 compared to under libc-2.19, gcc 4.8.4 on my computer. I am not sure, it might be a problem with Ubuntu packages of gcc, libc, or it might be a proble with gcc, libс directly. I've created a bug report at Launchpad: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1598618
