Thank you Tim As you said with -ffast-math option it works but others lines that seems to be parallelizable doesn´t e.g. Look at the two contiguous lines: INGTAR(HI,1:NETP)= ZERO !Compiller says : not vectorized: complicated access pattern. VAEMB(1:NEMB,HI,1:NETP)= ZERO ! Compiler says: note: LOOP VECTORIZED. The code I am working is quit old (and big) and I am only researching the (easy) ways to do it faster in actual computers Regards Wilfredo 2011/1/28 Tim Prince <n8tm@xxxxxxx>: > On 1/28/2011 11:03 AM, Wilfredo Sifuentes wrote: >> >> Dear all, >> In spite that some information on the WWW says that the SUM intrinsic >> function of Fortran 90 can be parallelizable, I found that gfortran >> 4.5 do not parallelize the following line (even if I fix or change >> “AHID” variable to “1” ): >> >> temporal= SUM(PERLIN(1:NLIN,AHID,1:NETP,1:NBLO)) >> >> Where PERLIN is defined as: REAL*8 PERLIN(MAXLIN,0:1,MAXETP,MAXBLO). >> The compiler report: “note: not vectorized: unsupported use in stmt.” >> Am I missing something? >> >> Regards >> Wilfredo > > I don't remember the diagnostic, but SUM vectorization would never occur > without options implying -fassociative-math (unfortunately, specifying that > one by itself doesn't help; -ffast-math does, but is too big a hammer). > Even beyond that, more information from you may be useful. > > -- > Tim Prince > >