https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94406
--- Comment #1 from Martin Jambor <jamborm at gcc dot gnu.org> --- For the record, the collected profiles both for the traditional "cycles:u" event and (originally unintended) "ls_stlf:u" event are below: -Ofast -march=native -mtune=native # Samples: 894K of event 'cycles:u' # Event count (approx.): 735979402525 # # Overhead Samples Command Shared Object Symbol # ........ ............ ............... ............................ ................................. # 67.18% 599542 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] mat_times_vec_ 11.40% 102686 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] shell_ 11.37% 101388 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] bi_cgstab_block_ 6.95% 62694 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] jacobian_ 1.88% 16957 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] flux_ 1.01% 9023 bwaves_r_peak.e libc-2.31.so [.] __memset_avx2_unaligned # Samples: 769K of event 'ls_stlf:u' # Event count (approx.): 154704730574 # # Overhead Samples Command Shared Object Symbol # ........ ............ ............... ............................ .................................... # 94.59% 612921 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] mat_times_vec_ 1.83% 88259 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] shell_ 1.12% 13615 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] flux_ 1.11% 43093 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] jacobian_ 1.05% 8746 bwaves_r_peak.e libc-2.31.so [.] __memset_avx2_unaligned -Ofast -march=native -mtune=native --param vect-epilogues-nomask=0 # Samples: 816K of event 'cycles:u' # Event count (approx.): 671104061807 # # Overhead Samples Command Shared Object Symbol # ........ ............ ............... ............................ ................................. # 64.07% 521532 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] mat_times_vec_ 12.50% 102670 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] shell_ 12.39% 100777 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] bi_cgstab_block_ 7.60% 62641 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] jacobian_ 2.06% 16925 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] flux_ 1.17% 9531 bwaves_r_peak.e libc-2.31.so [.] __memset_avx2_unaligned # Samples: 705K of event 'ls_stlf:u' # Event count (approx.): 55009340780 # # Overhead Samples Command Shared Object Symbol # ........ ............ ............... ............................ .............................. # 86.26% 532930 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] mat_times_vec_ 5.15% 88270 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] shell_ 3.17% 13696 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] flux_ 3.06% 57149 bwaves_r_peak.e bwaves_r_peak.experiment-m64 [.] jacobian_ 1.59% 9226 bwaves_r_peak.e libc-2.31.so [.] __memset_avx2_unaligned