Hi All, I am awaiting a green light to commit this patch.... or not.
Cheers Paul On Fri, 10 Mar 2023 at 16:49, Paul Richard Thomas < paul.richard.tho...@gmail.com> wrote: > Hi Thomas, > > Before answering that, I thought that I had better try the polyhedron > suite with -fwrapv and -std=legacy together. As far as I can see, all is > well and so, yes, I think that is a good idea. > > Cheers > > Paul > > > ================================================================================ > Date & Time : 9 Mar 2023 18:13:04 > Test Name : gfor_13 > Compile Command : gfc13 -ffast-math -funroll-loops -O3 -fwrapv -std=legacy > %n.f90 -o %n > Benchmarks : ac aermod air capacita channel2 doduc gas_dyn2 fatigue2 > induct2 linpk mp_prop_design nf protein rnflow test_fpu2 tfft2 > Maximum Times : 10000.0 > Target Error % : 0.100 > Minimum Repeats : 1 > Maximum Repeats : 2 > > Benchmark Compile Executable Ave Run Number Estim > Name (secs) (bytes) (secs) Repeats Err % > --------- ------- ---------- ------- ------- ------ > ac 0.00 55904 7.17 2 0.0628 > aermod 0.00 1280104 10.77 2 1.2769 > air 0.00 136392 4.09 2 0.4276 > capacita 0.00 102680 23.79 2 0.7587 > channel2 0.00 43928 108.59 2 0.5834 > doduc 0.00 194224 13.98 2 0.2468 > gas_dyn2 0.00 104080 105.46 2 0.1659 > fatigue2 0.00 90752 62.86 2 1.3092 > induct2 0.00 224920 58.08 2 0.6594 > linpk 0.00 51768 7.15 2 0.4892 > mp_prop_desi 0.00 48432 94.28 2 0.0164 > nf 0.00 64480 11.16 2 0.0134 > protein 0.00 140592 24.22 2 10.0347 > rnflow 0.00 197704 20.74 2 0.1904 > test_fpu2 0.00 147232 53.54 2 0.1093 > tfft2 0.00 43896 55.09 2 3.8688 > > Geometric Mean Execution Time = 26.19 seconds > > > ================================================================================ > > On Thu, 9 Mar 2023 at 17:30, Thomas Koenig <tkoe...@netcologne.de> wrote: > >> Hi Paul, >> >> >> > -fdefault-integer-8 does indeed fix the problem with >> > rnflow.f90 but breaks tfft2.f90, with a type mismatch at lines 36 and >> 44. >> > >> > integer(8), parameter :: jmul = 843314861 ! multiplicateur >> > integer(8), parameter :: jadd = 453816693 ! constante >> additive >> > Does the job and is portable. >> > >> >> I think -frwapv (as suggested by Jakub) would be the better choice. >> The problem is the linear congruential pseudo-random number generators >> which were much used in earlier times (and are still present in >> legacy code), which violate the Fortran standards by assuming silent >> truncation. >> >> If a new optimization breaks this (widespread, but illegal) idiom, >> maybe the best way to deal with it is to add -frwapv to -std=legacy. >> >> What do you think? >> >> Best regards >> >> Thomas >> > > > -- > "If you can't explain it simply, you don't understand it well enough" - > Albert Einstein > -- "If you can't explain it simply, you don't understand it well enough" - Albert Einstein
