On my system, I can clearly see it selecting the sse2 implementation (there is no AVX implementation of strstr)
$ gdb ./strstr (gdb) break strstr Breakpoint 1 at 0x1040 (gdb) run aa Starting program: /home/adconrad/Downloads/strstr aa Breakpoint 1, __strstr_sse2_unaligned () at ../sysdeps/x86_64/multiarch /strstr-sse2-unaligned.S -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1797335 Title: strstr() on ubuntu18.04 8 times slower than on ubuntu16 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1797335/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
