Bastiaan Braams via Gcc-bugs <gcc-bugs@gcc.gnu.org> writes: > Dear bug-gcc Group, > > This concerns gcc (gfortran) 14.2.1 on an x86_64 Red Hat Linux > system. I am using the ieee_next_after function from the (intrinsic) > ieee_arithmetic module in an inner loop and I noticed that it takes > very much CPU time. It seems unreasonable to me and so I am reporting > it as a bug.
Please file a bug in https://gcc.gnu.org/bugzilla Taking a look at your test case nearly all the time seems to be spent in changing the FPU state through ieee_procedure_entry/exit. The call to do unfortunately is not moved out of your loop. The actual next_after function is fairly cheap (< 2%) 30.04% a.out libgfortran.so.5.0.0 [.] 0x0000000000009623 | |--15.11%--_gfortran_ieee_procedure_entry@plt | MAIN__ | --14.93%--_gfortran_ieee_procedure_exit@plt MAIN__ 17.08% a.out libgfortran.so.5.0.0 [.] 0x0000000000009616 | |--8.76%--_gfortran_ieee_procedure_entry@plt | MAIN__ | --8.32%--_gfortran_ieee_procedure_exit@plt MAIN__ 13.92% a.out libgfortran.so.5.0.0 [.] 0x0000000000009764 | ---0x7f1929809760 _gfortran_ieee_procedure_exit MAIN__ 8.90% a.out libgfortran.so.5.0.0 [.] 0x0000000000009754 | ---0x7f1929809750 _gfortran_ieee_procedure_entry MAIN__ 5.61% a.out libgfortran.so.5.0.0 [.] 0x0000000000009627 | |--2.86%--_gfortran_ieee_procedure_exit@plt | MAIN__ | --2.75%--_gfortran_ieee_procedure_entry@plt MAIN__ ... 1.14% a.out libm.so.6 [.] nextafterf32x | ---nextafter@plt MAIN__ -Andi
