Re: [OMPI users] MPI_SUM and MPI_REAL16 with MPI_ALLREDUCE in fortran90
Something odd is definitely going on here. I'm able to replicate your problem with the intel compiler suite, but I can't quite figure out why -- it all works properly if I convert the app to C (and still use the MPI_REAL16 datatype with long double data). George and I are investigating; I've opened a ticket on this: https://svn.open-mpi.org/trac/ompi/ticket/1603 On Oct 28, 2008, at 6:35 AM, Julien Devriendt wrote: Yes point to point communication is OK with quad prec. and one-way reductions as well. I also tried my sample code on another platform (which sports AMD opterons instead of Intel CPUs) with the same compilers, and get the same *wrong* results with the call to MPI_ALLREDUCE in quad prec, so it does not seem to be a machine bug. Also altering a bit my sample code so as to replace MPI_SUM by MPI_MAX in the call to MPI_ALLREDUCE works perfectly well in quad prec !!! On Tue, 28 Oct 2008, Terry Frankcombe wrote: I assume you've confirmed that point to point communication works happily with quad prec on your machine? How about one-way reductions? On Tue, 2008-10-28 at 08:47 +, Julien Devriendt wrote: Thanks for your suggestions. I tried them all (declaring my variables as REAL*16 or REAL(16)) to no avail. I still get the wrong answer with my call to MPI_ALLREDUCE. I think the KINDs are compiler dependent. For Sun Studio Fortran, REAL*16 and REAL(16) are the same thing. For Intel, maybe it's different. I don't know. Try running this program: double precision xDP real(16) x16 real*16 xSTAR16 write(6,*) kind(xDP), kind(x16), kind(xSTAR16), kind(1.0_16) end and checking if the output matches your expectations. Jeff Squyres wrote: I dabble in Fortran but am not an expert -- is REAL(kind=16) the same as REAL*16? MPI_REAL16 should be a 16 byte REAL; I'm not 100% sure that REAL(kind=16) is the same thing...? On Oct 23, 2008, at 7:37 AM, Julien Devriendt wrote: Hi, I'm trying to do an MPI_ALLREDUCE with quadruple precision real and MPI_SUM and open mpi does not give me the correct answer (vartemp is equal to vartored instead of 2*vartored). Switching to double precision real works fine. My version of openmpi is 1.2.7 and it has been compiled with ifort v10.1 and icc/icpc at installation Here's the simple f90 code which fails: program test_quad implicit none include "mpif.h" real(kind=16) :: vartored(8),vartemp(8) integer :: nn,nslaves,my_index integer :: mpierror call MPI_INIT(mpierror) call MPI_COMM_SIZE(MPI_COMM_WORLD,nslaves,mpierror) call MPI_COMM_RANK(MPI_COMM_WORLD,my_index,mpierror) nn = 8 vartored = 1.0_16 vartemp = 0.0_16 print*,"P1 ",my_index,vartored call MPI_ALLREDUCE (vartored,vartemp,nn,MPI_REAL16,MPI_SUM,MPI_COMM_WORLD,mpierror) print*,"P2 ",my_index,vartemp stop end program test_quad Any idea why this happens? ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres Cisco Systems
Re: [OMPI users] MPI_SUM and MPI_REAL16 with MPI_ALLREDUCE in fortran90
Yes point to point communication is OK with quad prec. and one-way reductions as well. I also tried my sample code on another platform (which sports AMD opterons instead of Intel CPUs) with the same compilers, and get the same *wrong* results with the call to MPI_ALLREDUCE in quad prec, so it does not seem to be a machine bug. Also altering a bit my sample code so as to replace MPI_SUM by MPI_MAX in the call to MPI_ALLREDUCE works perfectly well in quad prec !!! On Tue, 28 Oct 2008, Terry Frankcombe wrote: I assume you've confirmed that point to point communication works happily with quad prec on your machine? How about one-way reductions? On Tue, 2008-10-28 at 08:47 +, Julien Devriendt wrote: Thanks for your suggestions. I tried them all (declaring my variables as REAL*16 or REAL(16)) to no avail. I still get the wrong answer with my call to MPI_ALLREDUCE. I think the KINDs are compiler dependent. For Sun Studio Fortran, REAL*16 and REAL(16) are the same thing. For Intel, maybe it's different. I don't know. Try running this program: double precision xDP real(16) x16 real*16 xSTAR16 write(6,*) kind(xDP), kind(x16), kind(xSTAR16), kind(1.0_16) end and checking if the output matches your expectations. Jeff Squyres wrote: I dabble in Fortran but am not an expert -- is REAL(kind=16) the same as REAL*16? MPI_REAL16 should be a 16 byte REAL; I'm not 100% sure that REAL(kind=16) is the same thing...? On Oct 23, 2008, at 7:37 AM, Julien Devriendt wrote: Hi, I'm trying to do an MPI_ALLREDUCE with quadruple precision real and MPI_SUM and open mpi does not give me the correct answer (vartemp is equal to vartored instead of 2*vartored). Switching to double precision real works fine. My version of openmpi is 1.2.7 and it has been compiled with ifort v10.1 and icc/icpc at installation Here's the simple f90 code which fails: program test_quad implicit none include "mpif.h" real(kind=16) :: vartored(8),vartemp(8) integer :: nn,nslaves,my_index integer :: mpierror call MPI_INIT(mpierror) call MPI_COMM_SIZE(MPI_COMM_WORLD,nslaves,mpierror) call MPI_COMM_RANK(MPI_COMM_WORLD,my_index,mpierror) nn = 8 vartored = 1.0_16 vartemp = 0.0_16 print*,"P1 ",my_index,vartored call MPI_ALLREDUCE (vartored,vartemp,nn,MPI_REAL16,MPI_SUM,MPI_COMM_WORLD,mpierror) print*,"P2 ",my_index,vartemp stop end program test_quad Any idea why this happens? ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users
Re: [OMPI users] MPI_SUM and MPI_REAL16 with MPI_ALLREDUCE in fortran90
I assume you've confirmed that point to point communication works happily with quad prec on your machine? How about one-way reductions? On Tue, 2008-10-28 at 08:47 +, Julien Devriendt wrote: > Thanks for your suggestions. > I tried them all (declaring my variables as REAL*16 or REAL(16)) to no > avail. I still get the wrong answer with my call to MPI_ALLREDUCE. > > > I think the KINDs are compiler dependent. For Sun Studio Fortran, REAL*16 > > and REAL(16) are the same thing. For Intel, maybe it's different. I don't > > know. Try running this program: > > > > double precision xDP > > real(16) x16 > > real*16 xSTAR16 > > write(6,*) kind(xDP), kind(x16), kind(xSTAR16), kind(1.0_16) > > end > > > > and checking if the output matches your expectations. > > > > Jeff Squyres wrote: > > > >> I dabble in Fortran but am not an expert -- is REAL(kind=16) the same as > >> REAL*16? MPI_REAL16 should be a 16 byte REAL; I'm not 100% sure that > >> REAL(kind=16) is the same thing...? > >> > >> On Oct 23, 2008, at 7:37 AM, Julien Devriendt wrote: > >> > >>> Hi, > >>> > >>> I'm trying to do an MPI_ALLREDUCE with quadruple precision real and > >>> MPI_SUM and open mpi does not give me the correct answer (vartemp > >>> is equal to vartored instead of 2*vartored). Switching to double > >>> precision > >>> real works fine. > >>> My version of openmpi is 1.2.7 and it has been compiled with ifort v10.1 > >>> and icc/icpc at installation > >>> > >>> Here's the simple f90 code which fails: > >>> > >>> program test_quad > >>> > >>>implicit none > >>> > >>>include "mpif.h" > >>> > >>>real(kind=16) :: vartored(8),vartemp(8) > >>>integer :: nn,nslaves,my_index > >>>integer :: mpierror > >>> > >>>call MPI_INIT(mpierror) > >>>call MPI_COMM_SIZE(MPI_COMM_WORLD,nslaves,mpierror) > >>>call MPI_COMM_RANK(MPI_COMM_WORLD,my_index,mpierror) > >>> > >>>nn = 8 > >>>vartored = 1.0_16 > >>>vartemp = 0.0_16 > >>>print*,"P1 ",my_index,vartored > >>>call MPI_ALLREDUCE > >>> (vartored,vartemp,nn,MPI_REAL16,MPI_SUM,MPI_COMM_WORLD,mpierror) > >>>print*,"P2 ",my_index,vartemp > >>> > >>>stop > >>> > >>> end program test_quad > >>> > >>> Any idea why this happens? > >> > > ___ > > users mailing list > > us...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/users > > > ___ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
Re: [OMPI users] MPI_SUM and MPI_REAL16 with MPI_ALLREDUCE in fortran90
Sorry, forgot to mention that running your sample program with ifort produces the expected result: 8 16 16 16 Thanks for your suggestions. I tried them all (declaring my variables as REAL*16 or REAL(16)) to no avail. I still get the wrong answer with my call to MPI_ALLREDUCE. I think the KINDs are compiler dependent. For Sun Studio Fortran, REAL*16 and REAL(16) are the same thing. For Intel, maybe it's different. I don't know. Try running this program: double precision xDP real(16) x16 real*16 xSTAR16 write(6,*) kind(xDP), kind(x16), kind(xSTAR16), kind(1.0_16) end and checking if the output matches your expectations. Jeff Squyres wrote: I dabble in Fortran but am not an expert -- is REAL(kind=16) the same as REAL*16? MPI_REAL16 should be a 16 byte REAL; I'm not 100% sure that REAL(kind=16) is the same thing...? On Oct 23, 2008, at 7:37 AM, Julien Devriendt wrote: Hi, I'm trying to do an MPI_ALLREDUCE with quadruple precision real and MPI_SUM and open mpi does not give me the correct answer (vartemp is equal to vartored instead of 2*vartored). Switching to double precision real works fine. My version of openmpi is 1.2.7 and it has been compiled with ifort v10.1 and icc/icpc at installation Here's the simple f90 code which fails: program test_quad implicit none include "mpif.h" real(kind=16) :: vartored(8),vartemp(8) integer :: nn,nslaves,my_index integer :: mpierror call MPI_INIT(mpierror) call MPI_COMM_SIZE(MPI_COMM_WORLD,nslaves,mpierror) call MPI_COMM_RANK(MPI_COMM_WORLD,my_index,mpierror) nn = 8 vartored = 1.0_16 vartemp = 0.0_16 print*,"P1 ",my_index,vartored call MPI_ALLREDUCE (vartored,vartemp,nn,MPI_REAL16,MPI_SUM,MPI_COMM_WORLD,mpierror) print*,"P2 ",my_index,vartemp stop end program test_quad Any idea why this happens? ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users
Re: [OMPI users] MPI_SUM and MPI_REAL16 with MPI_ALLREDUCE in fortran90
Yes it is: REAL(kind=16) = REAL*16 = 16 byte REAL in fortran, or a long double in C that is why I thought MPI_REAL16 should work. On Mon, 27 Oct 2008, Jeff Squyres wrote: I dabble in Fortran but am not an expert -- is REAL(kind=16) the same as REAL*16? MPI_REAL16 should be a 16 byte REAL; I'm not 100% sure that REAL(kind=16) is the same thing...? On Oct 23, 2008, at 7:37 AM, Julien Devriendt wrote: Hi, I'm trying to do an MPI_ALLREDUCE with quadruple precision real and MPI_SUM and open mpi does not give me the correct answer (vartemp is equal to vartored instead of 2*vartored). Switching to double precision real works fine. My version of openmpi is 1.2.7 and it has been compiled with ifort v10.1 and icc/icpc at installation Here's the simple f90 code which fails: program test_quad implicit none include "mpif.h" real(kind=16) :: vartored(8),vartemp(8) integer :: nn,nslaves,my_index integer :: mpierror call MPI_INIT(mpierror) call MPI_COMM_SIZE(MPI_COMM_WORLD,nslaves,mpierror) call MPI_COMM_RANK(MPI_COMM_WORLD,my_index,mpierror) nn = 8 vartored = 1.0_16 vartemp = 0.0_16 print*,"P1 ",my_index,vartored call MPI_ALLREDUCE (vartored,vartemp,nn,MPI_REAL16,MPI_SUM,MPI_COMM_WORLD,mpierror) print*,"P2 ",my_index,vartemp stop end program test_quad Any idea why this happens? Many thanks in advance! J. ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres Cisco Systems ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users
Re: [OMPI users] MPI_SUM and MPI_REAL16 with MPI_ALLREDUCE in fortran90
I think the KINDs are compiler dependent. For Sun Studio Fortran, REAL*16 and REAL(16) are the same thing. For Intel, maybe it's different. I don't know. Try running this program: double precision xDP real(16) x16 real*16 xSTAR16 write(6,*) kind(xDP), kind(x16), kind(xSTAR16), kind(1.0_16) end and checking if the output matches your expectations. Jeff Squyres wrote: I dabble in Fortran but am not an expert -- is REAL(kind=16) the same as REAL*16? MPI_REAL16 should be a 16 byte REAL; I'm not 100% sure that REAL(kind=16) is the same thing...? On Oct 23, 2008, at 7:37 AM, Julien Devriendt wrote: Hi, I'm trying to do an MPI_ALLREDUCE with quadruple precision real and MPI_SUM and open mpi does not give me the correct answer (vartemp is equal to vartored instead of 2*vartored). Switching to double precision real works fine. My version of openmpi is 1.2.7 and it has been compiled with ifort v10.1 and icc/icpc at installation Here's the simple f90 code which fails: program test_quad implicit none include "mpif.h" real(kind=16) :: vartored(8),vartemp(8) integer :: nn,nslaves,my_index integer :: mpierror call MPI_INIT(mpierror) call MPI_COMM_SIZE(MPI_COMM_WORLD,nslaves,mpierror) call MPI_COMM_RANK(MPI_COMM_WORLD,my_index,mpierror) nn = 8 vartored = 1.0_16 vartemp = 0.0_16 print*,"P1 ",my_index,vartored call MPI_ALLREDUCE (vartored,vartemp,nn,MPI_REAL16,MPI_SUM,MPI_COMM_WORLD,mpierror) print*,"P2 ",my_index,vartemp stop end program test_quad Any idea why this happens?
Re: [OMPI users] MPI_SUM and MPI_REAL16 with MPI_ALLREDUCE in fortran90
I dabble in Fortran but am not an expert -- is REAL(kind=16) the same as REAL*16? MPI_REAL16 should be a 16 byte REAL; I'm not 100% sure that REAL(kind=16) is the same thing...? On Oct 23, 2008, at 7:37 AM, Julien Devriendt wrote: Hi, I'm trying to do an MPI_ALLREDUCE with quadruple precision real and MPI_SUM and open mpi does not give me the correct answer (vartemp is equal to vartored instead of 2*vartored). Switching to double precision real works fine. My version of openmpi is 1.2.7 and it has been compiled with ifort v10.1 and icc/icpc at installation Here's the simple f90 code which fails: program test_quad implicit none include "mpif.h" real(kind=16) :: vartored(8),vartemp(8) integer :: nn,nslaves,my_index integer :: mpierror call MPI_INIT(mpierror) call MPI_COMM_SIZE(MPI_COMM_WORLD,nslaves,mpierror) call MPI_COMM_RANK(MPI_COMM_WORLD,my_index,mpierror) nn = 8 vartored = 1.0_16 vartemp = 0.0_16 print*,"P1 ",my_index,vartored call MPI_ALLREDUCE (vartored,vartemp,nn,MPI_REAL16,MPI_SUM,MPI_COMM_WORLD,mpierror) print*,"P2 ",my_index,vartemp stop end program test_quad Any idea why this happens? Many thanks in advance! J. ___ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres Cisco Systems
[OMPI users] MPI_SUM and MPI_REAL16 with MPI_ALLREDUCE in fortran90
Hi, I'm trying to do an MPI_ALLREDUCE with quadruple precision real and MPI_SUM and open mpi does not give me the correct answer (vartemp is equal to vartored instead of 2*vartored). Switching to double precision real works fine. My version of openmpi is 1.2.7 and it has been compiled with ifort v10.1 and icc/icpc at installation Here's the simple f90 code which fails: program test_quad implicit none include "mpif.h" real(kind=16) :: vartored(8),vartemp(8) integer :: nn,nslaves,my_index integer :: mpierror call MPI_INIT(mpierror) call MPI_COMM_SIZE(MPI_COMM_WORLD,nslaves,mpierror) call MPI_COMM_RANK(MPI_COMM_WORLD,my_index,mpierror) nn = 8 vartored = 1.0_16 vartemp = 0.0_16 print*,"P1 ",my_index,vartored call MPI_ALLREDUCE(vartored,vartemp,nn,MPI_REAL16,MPI_SUM,MPI_COMM_WORLD,mpierror) print*,"P2 ",my_index,vartemp stop end program test_quad Any idea why this happens? Many thanks in advance! J.
