March 2014 - mpiwg-fortran - mailman3.cels.anl.gov

Re: [MPIWG Fortran] Type of MPI_Status
by Bill Long 17 Mar '14

17 Mar '14

On Mar 16, 2014, at 7:47 AM, Rolf Rabenseifner <rabenseifner(a)hlrs.de> wrote: > Dear Junchao, > > I had not the time to go through all details, but I detected two issues: > > 1. TYPE(MPI_Status) must be declared with BIND(C). > It is missing in your example below. This seems to be needed only so that the routines that convert between the Fortran and C versions of MPI_Status are callable from C. It would have been a better design to have required that there be only one version of the MPI_Status struct - the Fortran and C structs are the same. That would require that the Fortran version have bind(c) for some uses, but a separate C_Status would not be needed. Also, the conversion routines could be discarded. > > 2. To declare an equivalent struct in C, i.e., > the C type MPI_F08_status, you should use MPI_Fint > and not int. Similarly, this complication would not be needed either. Even with the current scheme, making a struct for C that looks like the Fortran struct would seem to not have any purpose. It is useful to have a type definition in Fortran for the C struct (C_Status in the earlier example), which would be used in the currently needed conversion routines. I have yet to find any use for MPI_Fint. It appears to be for a C function to call a non-bind(c) Fortran routine that has INTEGER arguments, but that seems unlikely to actually happen. The library is in C and Fortran calls to C, not the other way around. Unless there is some obscure usage in the Fortran tools interface. (Craig and Jeff both know my solution to that. :) ) Cheers, Bill > > See MPI-3.0 p30:24-26 + ticket #415 and Sect. 17.2..5. > > Best regards > Rolf > > > > ----- Original Message ----- >> From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> >> To: "MPI-WG Fortran working group" <mpiwg-fortran(a)lists.mpi-forum.org> >> Sent: Saturday, March 15, 2014 10:52:42 PM >> Subject: Re: [MPIWG Fortran] Type of MPI_Status >> >> >> >> >> Rolf, you are right. Passing MPI%MPI_SOURCE as an argument will cause >> problems. Thanks. >> I list why I wanted to use c_int in MPI_Status. It is amusing. >> Without c_int, the design is something like >> >> >> type MPI_Status >> INTEGER :: MPI_SOURCE, MPI_ERROR, MPI_TAG >> ! other fields >> end type MPI_Status >> >> >> type(MPI_Status), parameter :: MPI_STATUS_IGNORE = ... >> >> >> type c_Status >> INTEGER(c_int) :: MPI_SOURCE, MPI_ERROR, MPI_TAG >> ! other fields >> end type c_Status >> >> >> type(c_Status), BIND(C, name="MPIR_C_STATUS_IGNORE") :: >> MPIR_C_STATUS_IGNORE >> >> >> ! Declare the C function prototype to bind >> function MPIR_Example_c(len, counts, status) result(ierror) BIND(C, >> name="MPI_Example") >> integer(c_int), intent(in) :: len >> integer(c_int), intent(in) :: counts(len) >> type(c_Status) :: status >> integer(c_int) :: ierror >> end function >> >> >> subroutine MPI_Example_f08(len, counts, status, ierror) >> integer, intent(in) :: len >> integer, intent(in) :: counts(len) >> type(MPI_Status) :: status >> integer, optional :: ierror_c >> >> >> integer(c_int), intent(in) :: len_c >> integer(c_int), intent(in) :: counts_c(len) >> type(c_Status) :: status_c >> integer(c_int) :: ierror_c >> >> >> if (c_int == kind(0) then ! Common case >> if (c_loc(status) == c_loc(MPI_STATUS_IGNORE)) then ! In C >> MPI_Example, it will checks again if status is 'IGNORE'. But we have >> to duplicate the work here due to type difference of >> MPI_STATUS_IGNORE and MPIR_C_STATUS_IGNORE. >> ierror = MPIR_Example_c(len, counts, MPIR_C_STATUS_IGNORE) >> else >> ! ierror = MPIR_Example_c(len, counts, status) ! Compile error since >> type(MPI_Status) mismatches type(c_Status) even c_int = INTEGER >> ierror = MPIR_Example_c(len, counts, status_c) >> status = status_c ! Note that = is overloaded. Can Compiler optimize >> away this copy propogation? probably not. >> endif ! This is bad since MPI_Status and c_Status are indeed the >> same. Even worse if status is an array. >> else >> len_c = len >> counts_c = counts >> if (c_loc(status) == c_loc(MPI_STATUS_IGNORE)) then >> ierror = MPIR_Example_c(len_c, counts_c, MPIR_C_STATUS_IGNORE) >> else >> ierror = MPIR_Example_c(len_c, counts_c, status_c) >> status = status_c >> endif >> endif >> >> >> if(present(ierror)) ierror = ierror_c >> end subroutine >> >> >> However, if I can use c_int in MPI_Status, then MPI_Status and >> c_Status are the same. I will have >> >> >> type MPI_Status >> INTEGER(c_int) :: MPI_SOURCE, MPI_ERROR, MPI_TAG >> ! other fields >> end type MPI_Status >> >> >> type(MPI_Status), BIND(C, name="MPI_STATUS_IGNORE") :: >> MPI_STATUS_IGNORE >> >> >> function MPIR_Example_c(len, counts, status) result(ierror) BIND(C, >> name="MPI_Example") >> integer(c_int), intent(in) :: len >> integer(c_int), intent(in) :: counts(len) >> type(MPI_Status) :: status ! Now use MPI_Status instead of c_Status >> integer(c_int) :: ierror >> end function >> >> >> subroutine MPI_Example_f08(len, counts, status, ierror) >> integer, intent(in) :: len >> integer, intent(in) :: counts(len) >> type(MPI_Status) :: status >> integer, optional :: ierror_c >> >> >> integer(c_int), intent(in) :: len_c >> integer(c_int), intent(in) :: counts_c(len) >> integer(c_int) :: ierror_c >> >> >> if (c_int == kind(0) then >> ierror = MPIR_Example_c(len, counts, status) ! Zero overhead incurred >> on status. >> else >> len_c = len >> counts_c = counts >> ierror = MPIR_Example_c(len_c, counts_c, status) >> endif >> >> >> if(present(ierror)) ierror = ierror_c >> end subroutine >> >> >> >> >> >> --Junchao Zhang >> >> >> On Sat, Mar 15, 2014 at 7:38 AM, Rolf Rabenseifner < >> rabenseifner(a)hlrs.de > wrote: >> >> >> Dear Junchao, >> >> As long as you use status%MPI_SOURCE in an expression, >> all is fine. >> >> If you pass it to an application routine dummy argument >> that is defined as INTEGER and your status%MPI_SOURCE >> is define as INTEGER(C_INT) then you may get compiler >> warnings or errors if size of both INTEGER types is different. >> >> CALL foo(status%MPI_SOURCE) >> >> with >> SUBROUTINE foo(rank) >> INTEGER :: rank >> >> >> Best regards >> Rolf >> >> >> ----- Original Message ----- >>> From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > >>> To: "MPI-WG Fortran working group" mpi-forum.org > >> >> >>> Sent: Saturday, March 15, 2014 11:54:38 AM >>> Subject: Re: [MPIWG Fortran] Type of MPI_Status >>> >>> >>> >>> My point is, with the C_INT implementation of MPI_Status, there >>> should be no compilation warnings AND runtime errors, even if >>> INTEGER kind is not c_int, since users can only operate MPI_Status >>> through their public interfaces, in which we take care of data >>> conversion. >>> >>> >>> But for other arguments of type INTEGER or array of INTEGERs, I can >>> not change their type. Users pass in an array of INTEGERs, I can >>> not >>> pretend they are c_int and don't do conversion. >>> >>> >>> >>> --Junchao Zhang >>> >>> >>> On Sat, Mar 15, 2014 at 3:33 AM, Rolf Rabenseifner < >>> rabenseifner(a)hlrs.de > wrote: >>> >>> >>> Junchao, >>> >>> With the erratum ticket #415, your implementation >>> with INTEGER(C_INT) is clearly wrong, >>> but who cares as long as an application programmer cannot >>> write an application code that produces compilation errors >>> or warnings or infos due to your wrong implementation >>> of TYPE(MPI_Status). >>> >>> I do not exactly now the rules about Fortran subroutine >>> prototype and overloading where handing over a INTEGER rank >>> or a INTEGER(C_INT) rank may cause to choose different interfaces. >>> >>> Maybe that Bill Long should comment on such strange things >>> before you define any field within TYPE(MPI_Status) or >>> any dummy argument in a routine declaration as INTEGER(C_INT) >>> instead of INTEGER as defined in MPI-3.0. >>> >>> >>> Best regards >>> Rolf >>> >>> ----- Original Message ----- >>>> From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > >>>> To: "MPI-WG Fortran working group" mpi-forum.org > >>> >>> >>>> Sent: Saturday, March 15, 2014 12:11:35 AM >>>> Subject: Re: [MPIWG Fortran] Type of MPI_Status >>>> >>>> >>>> >>>> Not sure if it is worth discussing. Even if INTEGER and C_INT are >>>> of >>>> different size, I think I can still use C_INT in MPI_Status. >>>> >>>> >>>> >>>> TYPE, BIND(C) :: MPI_Status >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR >>>> ... ! other fields >>>> END TYPE MPI_Status >>>> >>>> >>>> Since MPI_Status is a derived datatype, users access it through >>>> its >>>> public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). >>>> As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), >>>> who >>>> cares its internals. >>>> >>>> >>>> >>>> >>>> >>>> --Junchao Zhang >>>> >>>> >>>> On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner < >>>> rabenseifner(a)hlrs.de > wrote: >>>> >>>> >>>> Jeff is right. >>>> Bill's theoretical statement is also correct. >>>> >>>> And ticket#415 is also correct because it resolves an >>>> inconsistency >>>> within the mpi_f08 interface. >>>> >>>> Strange theoretical discussions are also there for >>>> long Fortran INTEGER may not be identical with some shorter >>>> INTEGER(C_int). >>>> As a side effect also solved by this ticket. >>>> >>>> >>>> Rolf >>>> >>>> ----- Original Message ----- >>>> >>>>> From: "Jeff Hammond" < jeff.science(a)gmail.com > >>>>> To: "MPI-WG Fortran working group" mpi-forum.org > >>>>> Sent: Thursday, March 13, 2014 4:12:56 PM >>>>> Subject: Re: [MPIWG Fortran] Type of MPI_Status >>>>> >>>>> MPI should test for interoperability of Fortran's default >>>>> integer >>>>> and >>>>> light the machine room on fire if it is not. >>>>> >>>>> Jeff >>>>> >>>>> On Thu, Mar 13, 2014 at 8:58 AM, Bill Long < longb(a)cray.com > >>>>> wrote: >>>>>> This does raise an earlier issue that it is >>>> >>>> >>>>>> possible that Fortran’s default INTEGER is not an >>>>>> interoperable >>>>>> type, and thus the MPI_Status type should not be a BIND(C) >>>>>> type >>>>>> if >>>>>> it has INTEGER components. Having BIND(C) does allow you to >>>>>> declare a C global name MPI_STATUS_IGNORE in Fortran, which >>>>>> solves >>>>>> one problem nicely. I don’t see any advantage to having >>>>>> INTEGER >>>>>> components (as opposed to INTEGER(C_Int), for example). So >>>>>> this >>>>>> seems to represent the worse of the two options. >>>>>> >>>>>> Cheers, >>>>>> Bill >>>>>> >>>>>> >>>>>> >>>>>> On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) >>>>>> < jsquyres(a)cisco.com > wrote: >>>>>> >>>>>>> Done. Good catch: >>>>>>> >>>>>>> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 >>>>>>> >>>>>>> This is a trivial ticket, but if you could make sure it's >>>>>>> ok, >>>>>>> I'll >>>>>>> send it to the mpi-forum list so that it can get added to >>>>>>> the >>>>>>> next meeting's agenda. >>>>>>> >>>>>>> >>>>>>> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner >>>>>>> < rabenseifner(a)hlrs.de > wrote: >>>>>>> >>>>>>>> Jeff and Junchao, >>>>>>>> >>>>>>>> it is a missing word INTEGER in this part of the sentence >>>>>>>> >>>>>>>> In whole MPI these three values are in Fortran INTEGER and >>>>>>>> nothing else >>>>>>>> >>>>>>>> Junchao, thank you for the hint that an erratum is neede >>>>>>>> to prevent from such misinterpretation >>>>>>>> >>>>>>>> Jeff, please can you file the errata ticket resulting in >>>>>>>> >>>>>>>> ... containing three public INTEGER fields named ... >>>>>>>> >>>>>>>> Best regards >>>>>>>> Rolf >>>>>>>> >>>>>>>> >>>>>>>> ----- Original Message ----- >>>>>>>>> From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > >>>>>>>>> To: "MPI-WG Fortran working group" >>>> >>>> >>>>>>>>> mpi-forum.org > >>>>>>>>> Sent: Thursday, March 13, 2014 4:49:49 AM >>>>>>>>> Subject: [MPIWG Fortran] Type of MPI_Status >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Hello, >>>>>>>>> >>>>>>>>> >>>>>>>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE >>>>>>>>> ’mpif.h’, >>>>>>>>> status >>>>>>>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With >>>>>>>>> Fortran >>>>>>>>> USE mpi_f08, status is defined as the Fortran BIND(C) >>>>>>>>> derived >>>>>>>>> type >>>>>>>>> TYPE(MPI_Status) containing three public fields named >>>>>>>>> MPI_SOURCE >>>>>>>>> , >>>>>>>>> MPI_TAG , and MPI_ERROR" >>>>>>>>> >>>>>>>>> In other words, it does't say type of the three public >>>>>>>>> fields >>>>>>>>> must be >>>>>>>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as >>>>>>>>> >>>>>>>>> >>>>>>>>> TYPE, BIND(C) :: MPI_Status >>>>>>>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR >>>>>>>>> ... ! other fields >>>>>>>>> END TYPE MPI_Status >>>>>>>>> >>>>>>>>> >>>>>>>>> I find it makes MPI_Status binding easier. Since this type >>>>>>>>> is >>>>>>>>> interoperable with C, I do not need to allocate temp >>>>>>>>> variables >>>>>>>>> to do >>>>>>>>> type conversion when INTEGER is not a C_INT. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> --Junchao Zhang >>>>>>>>> _______________________________________________ >>>>>>>>> mpiwg-fortran mailing list >>>>>>>>> mpiwg-fortran(a)lists.mpi-forum.org >>>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >>>>>>>> >>>>>>>> -- >>>>>>>> Dr. Rolf Rabenseifner . . . . . . . . . .. email >>>>>>>> rabenseifner(a)hlrs.de >>>>>>>> High Performance Computing Center (HLRS) . phone >>>>>>>> ++49(0)711/685-65530 >>>>>>>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / >>>>>>>> 685-65832 >>>>>>>> Head of Dpmt Parallel Computing . . . >>>>>>>> www.hlrs.de/people/rabenseifner >>>>>>>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: >>>>>>>> Room >>>>>>>> 1.307) >>>>>>>> _______________________________________________ >>>>>>>> mpiwg-fortran mailing list >>>>>>>> mpiwg-fortran(a)lists.mpi-forum.org >>>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Jeff Squyres >>>>>>> jsquyres(a)cisco.com >>>>>>> For corporate legal information go to: >>>>>>> http://www.cisco.com/web/about/doing_business/legal/cri/ >>>>>>> >>>>>>> _______________________________________________ >>>>>>> mpiwg-fortran mailing list >>>>>>> mpiwg-fortran(a)lists.mpi-forum.org >>>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >>>>>> >>>>>> Bill Long >>>>>> longb(a)cray.com >>>>>> Fortran Technical Suport & voice: >>>>>> 651-605-9024 >>>>>> Bioinformatics Software Development fax: >>>>>> 651-605-9142 >>>>>> Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, >>>>>> MN >>>>>> 55101 >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> mpiwg-fortran mailing list >>>>>> mpiwg-fortran(a)lists.mpi-forum.org >>>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >>>>> >>>>> >>>>> >>>>> -- >>>>> Jeff Hammond >>>>> jeff.science(a)gmail.com >>>>> _______________________________________________ >>>>> mpiwg-fortran mailing list >>>>> mpiwg-fortran(a)lists.mpi-forum.org >>>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >>>> >>>> -- >>>> Dr. Rolf Rabenseifner . . . . . . . . . .. email >>>> rabenseifner(a)hlrs.de >>>> High Performance Computing Center (HLRS) . phone >>>> ++49(0)711/685-65530 >>>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / >>>> 685-65832 >>>> Head of Dpmt Parallel Computing . . . >>>> www.hlrs.de/people/rabenseifner >>>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room >>>> 1.307) >>>> _______________________________________________ >>>> mpiwg-fortran mailing list >>>> mpiwg-fortran(a)lists.mpi-forum.org >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >>>> >>>> _______________________________________________ >>>> mpiwg-fortran mailing list >>>> mpiwg-fortran(a)lists.mpi-forum.org >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >>> >>> -- >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email >>> rabenseifner(a)hlrs.de >>> High Performance Computing Center (HLRS) . phone >>> ++49(0)711/685-65530 >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / >>> 685-65832 >>> Head of Dpmt Parallel Computing . . . >>> www.hlrs.de/people/rabenseifner >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room >>> 1.307) >>> _______________________________________________ >>> mpiwg-fortran mailing list >>> mpiwg-fortran(a)lists.mpi-forum.org >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >>> >>> _______________________________________________ >>> mpiwg-fortran mailing list >>> mpiwg-fortran(a)lists.mpi-forum.org >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >> >> -- >> Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de >> High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 >> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 >> Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner >> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) >> _______________________________________________ >> mpiwg-fortran mailing list >> mpiwg-fortran(a)lists.mpi-forum.org >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >> >> _______________________________________________ >> mpiwg-fortran mailing list >> mpiwg-fortran(a)lists.mpi-forum.org >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > -- > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran Bill Long longb(a)cray.com Fortran Technical Suport & voice: 651-605-9024 Bioinformatics Software Development fax: 651-605-9142 Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN 55101

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Re: [MPIWG Fortran] Type of MPI_Status
by Jeff Squyres (jsquyres) 17 Mar '14

17 Mar '14

To be clear, to-be-released OMPI's type for MPI_Status is: ! Get the KIND value that will be compatible with C, but also be a ! default INTEGER. That way, all the BIND(C) types below will be ! compatible with BIND(C) (because their member(s) will be BIND(C) ! compatible). integer, parameter :: OMPI_INT_KIND = kind(INTEGER) type, BIND(C) :: MPI_Status integer(OMPI_INT_KIND) :: MPI_SOURCE integer(OMPI_INT_KIND) :: MPI_TAG integer(OMPI_INT_KIND) :: MPI_ERROR integer(C_INT) OMPI_PRIVATE :: c_cancelled integer(C_SIZE_T) OMPI_PRIVATE :: c_count end type MPI_Status and also type, BIND(C) :: MPI_Comm integer(OMPI_INT_KIND) :: MPI_VAL end type MPI_Comm etc. I have to think through the ABI implications of this, however -- it may not make it into the v1.7.5/1.8 series if it creates an ABI incompatibility with OMPI 1.7.3/1.7.4 (i.e., it may have to wait until 1.9). On Mar 17, 2014, at 12:52 PM, Craig Rasmussen <rasmus(a)cas.uoregon.edu> wrote: > Jeff and I had a similar conversation last week. It is my viewpoint that the MPI-3 interfaces are formal interfaces that can be adapted by an implementation in a way that formally meets the specification. > > For Open MPI I believe that Jeff will add configuration magic to check is INTEGER(C_INT) and default INTEGER have the same KIND value. This should be true for 100% of the compilers. If not, then that compiler will not be able to build Open MPI. > > The use of INTEGER(C_INT) to replace the default INTEGER in the MPI types is needed to stopped compiler warning from GNU. We did this work (adding BIND(C) to gfortran) at Los Alamos and I think we perhaps got carried away with the warning messages. > > Craig Rasmussen > CAS Scientific Programmer > rasmus(a)cas.uoregon.edu > > > > > On Mar 14, 2014, at 4:11 PM, Junchao Zhang wrote: > >> Not sure if it is worth discussing. Even if INTEGER and C_INT are of different size, I think I can still use C_INT in MPI_Status. >> >> TYPE, BIND(C) :: MPI_Status >> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR >> ... ! other fields >> END TYPE MPI_Status >> >> Since MPI_Status is a derived datatype, users access it through its public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). >> As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), who cares its internals. >> >> >> --Junchao Zhang >> >> >> On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner <rabenseifner(a)hlrs.de> wrote: >> Jeff is right. >> Bill's theoretical statement is also correct. >> >> And ticket#415 is also correct because it resolves an inconsistency >> within the mpi_f08 interface. >> >> Strange theoretical discussions are also there for >> long Fortran INTEGER may not be identical with some shorter INTEGER(C_int). >> As a side effect also solved by this ticket. >> >> Rolf >> >> ----- Original Message ----- >> > From: "Jeff Hammond" <jeff.science(a)gmail.com> >> > To: "MPI-WG Fortran working group" mpi-forum.org> >> > Sent: Thursday, March 13, 2014 4:12:56 PM >> > Subject: Re: [MPIWG Fortran] Type of MPI_Status >> > >> > MPI should test for interoperability of Fortran's default integer and >> > light the machine room on fire if it is not. >> > >> > Jeff >> > >> > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long <longb(a)cray.com> wrote: >> > > This does raise an earlier issue that it is >> > > possible that Fortran’s default INTEGER is not an interoperable >> > > type, and thus the MPI_Status type should not be a BIND(C) type if >> > > it has INTEGER components. Having BIND(C) does allow you to >> > > declare a C global name MPI_STATUS_IGNORE in Fortran, which solves >> > > one problem nicely. I don’t see any advantage to having INTEGER >> > > components (as opposed to INTEGER(C_Int), for example). So this >> > > seems to represent the worse of the two options. >> > > >> > > Cheers, >> > > Bill >> > > >> > > >> > > >> > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) >> > > <jsquyres(a)cisco.com> wrote: >> > > >> > >> Done. Good catch: >> > >> >> > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 >> > >> >> > >> This is a trivial ticket, but if you could make sure it's ok, I'll >> > >> send it to the mpi-forum list so that it can get added to the >> > >> next meeting's agenda. >> > >> >> > >> >> > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner >> > >> <rabenseifner(a)hlrs.de> wrote: >> > >> >> > >>> Jeff and Junchao, >> > >>> >> > >>> it is a missing word INTEGER in this part of the sentence >> > >>> >> > >>> In whole MPI these three values are in Fortran INTEGER and >> > >>> nothing else >> > >>> >> > >>> Junchao, thank you for the hint that an erratum is neede >> > >>> to prevent from such misinterpretation >> > >>> >> > >>> Jeff, please can you file the errata ticket resulting in >> > >>> >> > >>> ... containing three public INTEGER fields named ... >> > >>> >> > >>> Best regards >> > >>> Rolf >> > >>> >> > >>> >> > >>> ----- Original Message ----- >> > >>>> From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> >> > >>>> To: "MPI-WG Fortran working group" >> > >>>> mpi-forum.org> >> > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM >> > >>>> Subject: [MPIWG Fortran] Type of MPI_Status >> > >>>> >> > >>>> >> > >>>> >> > >>>> >> > >>>> Hello, >> > >>>> >> > >>>> >> > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE ’mpif.h’, >> > >>>> status >> > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With >> > >>>> Fortran >> > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) derived >> > >>>> type >> > >>>> TYPE(MPI_Status) containing three public fields named MPI_SOURCE >> > >>>> , >> > >>>> MPI_TAG , and MPI_ERROR" >> > >>>> >> > >>>> In other words, it does't say type of the three public fields >> > >>>> must be >> > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as >> > >>>> >> > >>>> >> > >>>> TYPE, BIND(C) :: MPI_Status >> > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR >> > >>>> ... ! other fields >> > >>>> END TYPE MPI_Status >> > >>>> >> > >>>> >> > >>>> I find it makes MPI_Status binding easier. Since this type is >> > >>>> interoperable with C, I do not need to allocate temp variables >> > >>>> to do >> > >>>> type conversion when INTEGER is not a C_INT. >> > >>>> >> > >>>> >> > >>>> >> > >>>> --Junchao Zhang >> > >>>> _______________________________________________ >> > >>>> mpiwg-fortran mailing list >> > >>>> mpiwg-fortran(a)lists.mpi-forum.org >> > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >> > >>> >> > >>> -- >> > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email >> > >>> rabenseifner(a)hlrs.de >> > >>> High Performance Computing Center (HLRS) . phone >> > >>> ++49(0)711/685-65530 >> > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / >> > >>> 685-65832 >> > >>> Head of Dpmt Parallel Computing . . . >> > >>> www.hlrs.de/people/rabenseifner >> > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room >> > >>> 1.307) >> > >>> _______________________________________________ >> > >>> mpiwg-fortran mailing list >> > >>> mpiwg-fortran(a)lists.mpi-forum.org >> > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >> > >> >> > >> >> > >> -- >> > >> Jeff Squyres >> > >> jsquyres(a)cisco.com >> > >> For corporate legal information go to: >> > >> http://www.cisco.com/web/about/doing_business/legal/cri/ >> > >> >> > >> _______________________________________________ >> > >> mpiwg-fortran mailing list >> > >> mpiwg-fortran(a)lists.mpi-forum.org >> > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >> > > >> > > Bill Long >> > > longb(a)cray.com >> > > Fortran Technical Suport & voice: >> > > 651-605-9024 >> > > Bioinformatics Software Development fax: >> > > 651-605-9142 >> > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN >> > > 55101 >> > > >> > > >> > > _______________________________________________ >> > > mpiwg-fortran mailing list >> > > mpiwg-fortran(a)lists.mpi-forum.org >> > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >> > >> > >> > >> > -- >> > Jeff Hammond >> > jeff.science(a)gmail.com >> > _______________________________________________ >> > mpiwg-fortran mailing list >> > mpiwg-fortran(a)lists.mpi-forum.org >> > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >> >> -- >> Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de >> High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 >> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 >> Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner >> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) >> _______________________________________________ >> mpiwg-fortran mailing list >> mpiwg-fortran(a)lists.mpi-forum.org >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >> >> _______________________________________________ >> mpiwg-fortran mailing list >> mpiwg-fortran(a)lists.mpi-forum.org >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran -- Jeff Squyres jsquyres(a)cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/

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Re: [MPIWG Fortran] Type of MPI_Status
by Craig Rasmussen 17 Mar '14

17 Mar '14

Jeff and I had a similar conversation last week. It is my viewpoint that the MPI-3 interfaces are formal interfaces that can be adapted by an implementation in a way that formally meets the specification. For Open MPI I believe that Jeff will add configuration magic to check is INTEGER(C_INT) and default INTEGER have the same KIND value. This should be true for 100% of the compilers. If not, then that compiler will not be able to build Open MPI. The use of INTEGER(C_INT) to replace the default INTEGER in the MPI types is needed to stopped compiler warning from GNU. We did this work (adding BIND(C) to gfortran) at Los Alamos and I think we perhaps got carried away with the warning messages. Craig Rasmussen CAS Scientific Programmer rasmus(a)cas.uoregon.edu On Mar 14, 2014, at 4:11 PM, Junchao Zhang wrote: > Not sure if it is worth discussing. Even if INTEGER and C_INT are of different size, I think I can still use C_INT in MPI_Status. > > TYPE, BIND(C) :: MPI_Status > INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > ... ! other fields > END TYPE MPI_Status > > Since MPI_Status is a derived datatype, users access it through its public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). > As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), who cares its internals. > > > --Junchao Zhang > > > On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner <rabenseifner(a)hlrs.de> wrote: > Jeff is right. > Bill's theoretical statement is also correct. > > And ticket#415 is also correct because it resolves an inconsistency > within the mpi_f08 interface. > > Strange theoretical discussions are also there for > long Fortran INTEGER may not be identical with some shorter INTEGER(C_int). > As a side effect also solved by this ticket. > > Rolf > > ----- Original Message ----- > > From: "Jeff Hammond" <jeff.science(a)gmail.com> > > To: "MPI-WG Fortran working group" mpi-forum.org> > > Sent: Thursday, March 13, 2014 4:12:56 PM > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > MPI should test for interoperability of Fortran's default integer and > > light the machine room on fire if it is not. > > > > Jeff > > > > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long <longb(a)cray.com> wrote: > > > This does raise an earlier issue that it is > > > possible that Fortran’s default INTEGER is not an interoperable > > > type, and thus the MPI_Status type should not be a BIND(C) type if > > > it has INTEGER components. Having BIND(C) does allow you to > > > declare a C global name MPI_STATUS_IGNORE in Fortran, which solves > > > one problem nicely. I don’t see any advantage to having INTEGER > > > components (as opposed to INTEGER(C_Int), for example). So this > > > seems to represent the worse of the two options. > > > > > > Cheers, > > > Bill > > > > > > > > > > > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) > > > <jsquyres(a)cisco.com> wrote: > > > > > >> Done. Good catch: > > >> > > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 > > >> > > >> This is a trivial ticket, but if you could make sure it's ok, I'll > > >> send it to the mpi-forum list so that it can get added to the > > >> next meeting's agenda. > > >> > > >> > > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner > > >> <rabenseifner(a)hlrs.de> wrote: > > >> > > >>> Jeff and Junchao, > > >>> > > >>> it is a missing word INTEGER in this part of the sentence > > >>> > > >>> In whole MPI these three values are in Fortran INTEGER and > > >>> nothing else > > >>> > > >>> Junchao, thank you for the hint that an erratum is neede > > >>> to prevent from such misinterpretation > > >>> > > >>> Jeff, please can you file the errata ticket resulting in > > >>> > > >>> ... containing three public INTEGER fields named ... > > >>> > > >>> Best regards > > >>> Rolf > > >>> > > >>> > > >>> ----- Original Message ----- > > >>>> From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> > > >>>> To: "MPI-WG Fortran working group" > > >>>> mpi-forum.org> > > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM > > >>>> Subject: [MPIWG Fortran] Type of MPI_Status > > >>>> > > >>>> > > >>>> > > >>>> > > >>>> Hello, > > >>>> > > >>>> > > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE ’mpif.h’, > > >>>> status > > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With > > >>>> Fortran > > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) derived > > >>>> type > > >>>> TYPE(MPI_Status) containing three public fields named MPI_SOURCE > > >>>> , > > >>>> MPI_TAG , and MPI_ERROR" > > >>>> > > >>>> In other words, it does't say type of the three public fields > > >>>> must be > > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as > > >>>> > > >>>> > > >>>> TYPE, BIND(C) :: MPI_Status > > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > >>>> ... ! other fields > > >>>> END TYPE MPI_Status > > >>>> > > >>>> > > >>>> I find it makes MPI_Status binding easier. Since this type is > > >>>> interoperable with C, I do not need to allocate temp variables > > >>>> to do > > >>>> type conversion when INTEGER is not a C_INT. > > >>>> > > >>>> > > >>>> > > >>>> --Junchao Zhang > > >>>> _______________________________________________ > > >>>> mpiwg-fortran mailing list > > >>>> mpiwg-fortran(a)lists.mpi-forum.org > > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > >>> > > >>> -- > > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email > > >>> rabenseifner(a)hlrs.de > > >>> High Performance Computing Center (HLRS) . phone > > >>> ++49(0)711/685-65530 > > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > >>> 685-65832 > > >>> Head of Dpmt Parallel Computing . . . > > >>> www.hlrs.de/people/rabenseifner > > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > > >>> 1.307) > > >>> _______________________________________________ > > >>> mpiwg-fortran mailing list > > >>> mpiwg-fortran(a)lists.mpi-forum.org > > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > >> > > >> > > >> -- > > >> Jeff Squyres > > >> jsquyres(a)cisco.com > > >> For corporate legal information go to: > > >> http://www.cisco.com/web/about/doing_business/legal/cri/ > > >> > > >> _______________________________________________ > > >> mpiwg-fortran mailing list > > >> mpiwg-fortran(a)lists.mpi-forum.org > > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > Bill Long > > > longb(a)cray.com > > > Fortran Technical Suport & voice: > > > 651-605-9024 > > > Bioinformatics Software Development fax: > > > 651-605-9142 > > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN > > > 55101 > > > > > > > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > -- > > Jeff Hammond > > jeff.science(a)gmail.com > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > -- > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran

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Re: [MPIWG Fortran] Type of MPI_Status
by Rolf Rabenseifner 16 Mar '14

16 Mar '14

Dear Junchao, I had not the time to go through all details, but I detected two issues: 1. TYPE(MPI_Status) must be declared with BIND(C). It is missing in your example below. 2. To declare an equivalent struct in C, i.e., the C type MPI_F08_status, you should use MPI_Fint and not int. See MPI-3.0 p30:24-26 + ticket #415 and Sect. 17.2..5. Best regards Rolf ----- Original Message ----- > From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> > To: "MPI-WG Fortran working group" <mpiwg-fortran(a)lists.mpi-forum.org> > Sent: Saturday, March 15, 2014 10:52:42 PM > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > Rolf, you are right. Passing MPI%MPI_SOURCE as an argument will cause > problems. Thanks. > I list why I wanted to use c_int in MPI_Status. It is amusing. > Without c_int, the design is something like > > > type MPI_Status > INTEGER :: MPI_SOURCE, MPI_ERROR, MPI_TAG > ! other fields > end type MPI_Status > > > type(MPI_Status), parameter :: MPI_STATUS_IGNORE = ... > > > type c_Status > INTEGER(c_int) :: MPI_SOURCE, MPI_ERROR, MPI_TAG > ! other fields > end type c_Status > > > type(c_Status), BIND(C, name="MPIR_C_STATUS_IGNORE") :: > MPIR_C_STATUS_IGNORE > > > ! Declare the C function prototype to bind > function MPIR_Example_c(len, counts, status) result(ierror) BIND(C, > name="MPI_Example") > integer(c_int), intent(in) :: len > integer(c_int), intent(in) :: counts(len) > type(c_Status) :: status > integer(c_int) :: ierror > end function > > > subroutine MPI_Example_f08(len, counts, status, ierror) > integer, intent(in) :: len > integer, intent(in) :: counts(len) > type(MPI_Status) :: status > integer, optional :: ierror_c > > > integer(c_int), intent(in) :: len_c > integer(c_int), intent(in) :: counts_c(len) > type(c_Status) :: status_c > integer(c_int) :: ierror_c > > > if (c_int == kind(0) then ! Common case > if (c_loc(status) == c_loc(MPI_STATUS_IGNORE)) then ! In C > MPI_Example, it will checks again if status is 'IGNORE'. But we have > to duplicate the work here due to type difference of > MPI_STATUS_IGNORE and MPIR_C_STATUS_IGNORE. > ierror = MPIR_Example_c(len, counts, MPIR_C_STATUS_IGNORE) > else > ! ierror = MPIR_Example_c(len, counts, status) ! Compile error since > type(MPI_Status) mismatches type(c_Status) even c_int = INTEGER > ierror = MPIR_Example_c(len, counts, status_c) > status = status_c ! Note that = is overloaded. Can Compiler optimize > away this copy propogation? probably not. > endif ! This is bad since MPI_Status and c_Status are indeed the > same. Even worse if status is an array. > else > len_c = len > counts_c = counts > if (c_loc(status) == c_loc(MPI_STATUS_IGNORE)) then > ierror = MPIR_Example_c(len_c, counts_c, MPIR_C_STATUS_IGNORE) > else > ierror = MPIR_Example_c(len_c, counts_c, status_c) > status = status_c > endif > endif > > > if(present(ierror)) ierror = ierror_c > end subroutine > > > However, if I can use c_int in MPI_Status, then MPI_Status and > c_Status are the same. I will have > > > type MPI_Status > INTEGER(c_int) :: MPI_SOURCE, MPI_ERROR, MPI_TAG > ! other fields > end type MPI_Status > > > type(MPI_Status), BIND(C, name="MPI_STATUS_IGNORE") :: > MPI_STATUS_IGNORE > > > function MPIR_Example_c(len, counts, status) result(ierror) BIND(C, > name="MPI_Example") > integer(c_int), intent(in) :: len > integer(c_int), intent(in) :: counts(len) > type(MPI_Status) :: status ! Now use MPI_Status instead of c_Status > integer(c_int) :: ierror > end function > > > subroutine MPI_Example_f08(len, counts, status, ierror) > integer, intent(in) :: len > integer, intent(in) :: counts(len) > type(MPI_Status) :: status > integer, optional :: ierror_c > > > integer(c_int), intent(in) :: len_c > integer(c_int), intent(in) :: counts_c(len) > integer(c_int) :: ierror_c > > > if (c_int == kind(0) then > ierror = MPIR_Example_c(len, counts, status) ! Zero overhead incurred > on status. > else > len_c = len > counts_c = counts > ierror = MPIR_Example_c(len_c, counts_c, status) > endif > > > if(present(ierror)) ierror = ierror_c > end subroutine > > > > > > --Junchao Zhang > > > On Sat, Mar 15, 2014 at 7:38 AM, Rolf Rabenseifner < > rabenseifner(a)hlrs.de > wrote: > > > Dear Junchao, > > As long as you use status%MPI_SOURCE in an expression, > all is fine. > > If you pass it to an application routine dummy argument > that is defined as INTEGER and your status%MPI_SOURCE > is define as INTEGER(C_INT) then you may get compiler > warnings or errors if size of both INTEGER types is different. > > CALL foo(status%MPI_SOURCE) > > with > SUBROUTINE foo(rank) > INTEGER :: rank > > > Best regards > Rolf > > > ----- Original Message ----- > > From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > > > Sent: Saturday, March 15, 2014 11:54:38 AM > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > > > My point is, with the C_INT implementation of MPI_Status, there > > should be no compilation warnings AND runtime errors, even if > > INTEGER kind is not c_int, since users can only operate MPI_Status > > through their public interfaces, in which we take care of data > > conversion. > > > > > > But for other arguments of type INTEGER or array of INTEGERs, I can > > not change their type. Users pass in an array of INTEGERs, I can > > not > > pretend they are c_int and don't do conversion. > > > > > > > > --Junchao Zhang > > > > > > On Sat, Mar 15, 2014 at 3:33 AM, Rolf Rabenseifner < > > rabenseifner(a)hlrs.de > wrote: > > > > > > Junchao, > > > > With the erratum ticket #415, your implementation > > with INTEGER(C_INT) is clearly wrong, > > but who cares as long as an application programmer cannot > > write an application code that produces compilation errors > > or warnings or infos due to your wrong implementation > > of TYPE(MPI_Status). > > > > I do not exactly now the rules about Fortran subroutine > > prototype and overloading where handing over a INTEGER rank > > or a INTEGER(C_INT) rank may cause to choose different interfaces. > > > > Maybe that Bill Long should comment on such strange things > > before you define any field within TYPE(MPI_Status) or > > any dummy argument in a routine declaration as INTEGER(C_INT) > > instead of INTEGER as defined in MPI-3.0. > > > > > > Best regards > > Rolf > > > > ----- Original Message ----- > > > From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > > > > > > Sent: Saturday, March 15, 2014 12:11:35 AM > > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > > > > > > > Not sure if it is worth discussing. Even if INTEGER and C_INT are > > > of > > > different size, I think I can still use C_INT in MPI_Status. > > > > > > > > > > > > TYPE, BIND(C) :: MPI_Status > > > INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > > ... ! other fields > > > END TYPE MPI_Status > > > > > > > > > Since MPI_Status is a derived datatype, users access it through > > > its > > > public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). > > > As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), > > > who > > > cares its internals. > > > > > > > > > > > > > > > > > > --Junchao Zhang > > > > > > > > > On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner < > > > rabenseifner(a)hlrs.de > wrote: > > > > > > > > > Jeff is right. > > > Bill's theoretical statement is also correct. > > > > > > And ticket#415 is also correct because it resolves an > > > inconsistency > > > within the mpi_f08 interface. > > > > > > Strange theoretical discussions are also there for > > > long Fortran INTEGER may not be identical with some shorter > > > INTEGER(C_int). > > > As a side effect also solved by this ticket. > > > > > > > > > Rolf > > > > > > ----- Original Message ----- > > > > > > > From: "Jeff Hammond" < jeff.science(a)gmail.com > > > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > > > Sent: Thursday, March 13, 2014 4:12:56 PM > > > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > > > MPI should test for interoperability of Fortran's default > > > > integer > > > > and > > > > light the machine room on fire if it is not. > > > > > > > > Jeff > > > > > > > > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long < longb(a)cray.com > > > > > wrote: > > > > > This does raise an earlier issue that it is > > > > > > > > > > > possible that Fortran’s default INTEGER is not an > > > > > interoperable > > > > > type, and thus the MPI_Status type should not be a BIND(C) > > > > > type > > > > > if > > > > > it has INTEGER components. Having BIND(C) does allow you to > > > > > declare a C global name MPI_STATUS_IGNORE in Fortran, which > > > > > solves > > > > > one problem nicely. I don’t see any advantage to having > > > > > INTEGER > > > > > components (as opposed to INTEGER(C_Int), for example). So > > > > > this > > > > > seems to represent the worse of the two options. > > > > > > > > > > Cheers, > > > > > Bill > > > > > > > > > > > > > > > > > > > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) > > > > > < jsquyres(a)cisco.com > wrote: > > > > > > > > > >> Done. Good catch: > > > > >> > > > > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 > > > > >> > > > > >> This is a trivial ticket, but if you could make sure it's > > > > >> ok, > > > > >> I'll > > > > >> send it to the mpi-forum list so that it can get added to > > > > >> the > > > > >> next meeting's agenda. > > > > >> > > > > >> > > > > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner > > > > >> < rabenseifner(a)hlrs.de > wrote: > > > > >> > > > > >>> Jeff and Junchao, > > > > >>> > > > > >>> it is a missing word INTEGER in this part of the sentence > > > > >>> > > > > >>> In whole MPI these three values are in Fortran INTEGER and > > > > >>> nothing else > > > > >>> > > > > >>> Junchao, thank you for the hint that an erratum is neede > > > > >>> to prevent from such misinterpretation > > > > >>> > > > > >>> Jeff, please can you file the errata ticket resulting in > > > > >>> > > > > >>> ... containing three public INTEGER fields named ... > > > > >>> > > > > >>> Best regards > > > > >>> Rolf > > > > >>> > > > > >>> > > > > >>> ----- Original Message ----- > > > > >>>> From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > > > >>>> To: "MPI-WG Fortran working group" > > > > > > > > > > >>>> mpi-forum.org > > > > > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM > > > > >>>> Subject: [MPIWG Fortran] Type of MPI_Status > > > > >>>> > > > > >>>> > > > > >>>> > > > > >>>> > > > > >>>> Hello, > > > > >>>> > > > > >>>> > > > > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE > > > > >>>> ’mpif.h’, > > > > >>>> status > > > > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With > > > > >>>> Fortran > > > > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) > > > > >>>> derived > > > > >>>> type > > > > >>>> TYPE(MPI_Status) containing three public fields named > > > > >>>> MPI_SOURCE > > > > >>>> , > > > > >>>> MPI_TAG , and MPI_ERROR" > > > > >>>> > > > > >>>> In other words, it does't say type of the three public > > > > >>>> fields > > > > >>>> must be > > > > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as > > > > >>>> > > > > >>>> > > > > >>>> TYPE, BIND(C) :: MPI_Status > > > > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > > > >>>> ... ! other fields > > > > >>>> END TYPE MPI_Status > > > > >>>> > > > > >>>> > > > > >>>> I find it makes MPI_Status binding easier. Since this type > > > > >>>> is > > > > >>>> interoperable with C, I do not need to allocate temp > > > > >>>> variables > > > > >>>> to do > > > > >>>> type conversion when INTEGER is not a C_INT. > > > > >>>> > > > > >>>> > > > > >>>> > > > > >>>> --Junchao Zhang > > > > >>>> _______________________________________________ > > > > >>>> mpiwg-fortran mailing list > > > > >>>> mpiwg-fortran(a)lists.mpi-forum.org > > > > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > >>> > > > > >>> -- > > > > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email > > > > >>> rabenseifner(a)hlrs.de > > > > >>> High Performance Computing Center (HLRS) . phone > > > > >>> ++49(0)711/685-65530 > > > > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > > > >>> 685-65832 > > > > >>> Head of Dpmt Parallel Computing . . . > > > > >>> www.hlrs.de/people/rabenseifner > > > > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: > > > > >>> Room > > > > >>> 1.307) > > > > >>> _______________________________________________ > > > > >>> mpiwg-fortran mailing list > > > > >>> mpiwg-fortran(a)lists.mpi-forum.org > > > > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > >> > > > > >> > > > > >> -- > > > > >> Jeff Squyres > > > > >> jsquyres(a)cisco.com > > > > >> For corporate legal information go to: > > > > >> http://www.cisco.com/web/about/doing_business/legal/cri/ > > > > >> > > > > >> _______________________________________________ > > > > >> mpiwg-fortran mailing list > > > > >> mpiwg-fortran(a)lists.mpi-forum.org > > > > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > > > Bill Long > > > > > longb(a)cray.com > > > > > Fortran Technical Suport & voice: > > > > > 651-605-9024 > > > > > Bioinformatics Software Development fax: > > > > > 651-605-9142 > > > > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, > > > > > MN > > > > > 55101 > > > > > > > > > > > > > > > _______________________________________________ > > > > > mpiwg-fortran mailing list > > > > > mpiwg-fortran(a)lists.mpi-forum.org > > > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > > > > > > > > > -- > > > > Jeff Hammond > > > > jeff.science(a)gmail.com > > > > _______________________________________________ > > > > mpiwg-fortran mailing list > > > > mpiwg-fortran(a)lists.mpi-forum.org > > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > -- > > > Dr. Rolf Rabenseifner . . . . . . . . . .. email > > > rabenseifner(a)hlrs.de > > > High Performance Computing Center (HLRS) . phone > > > ++49(0)711/685-65530 > > > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > > 685-65832 > > > Head of Dpmt Parallel Computing . . . > > > www.hlrs.de/people/rabenseifner > > > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > > > 1.307) > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > -- > > Dr. Rolf Rabenseifner . . . . . . . . . .. email > > rabenseifner(a)hlrs.de > > High Performance Computing Center (HLRS) . phone > > ++49(0)711/685-65530 > > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > 685-65832 > > Head of Dpmt Parallel Computing . . . > > www.hlrs.de/people/rabenseifner > > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > > 1.307) > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > -- > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran -- Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307)

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Re: [MPIWG Fortran] Type of MPI_Status
by Junchao Zhang 15 Mar '14

15 Mar '14

Rolf, you are right. Passing MPI%MPI_SOURCE as an argument will cause problems. Thanks. I list why I wanted to use c_int in MPI_Status. It is amusing. Without c_int, the design is something like type MPI_Status INTEGER :: MPI_SOURCE, MPI_ERROR, MPI_TAG ! other fields end type MPI_Status type(MPI_Status), parameter :: MPI_STATUS_IGNORE = ... type c_Status INTEGER(c_int) :: MPI_SOURCE, MPI_ERROR, MPI_TAG ! other fields end type c_Status type(c_Status), BIND(C, name="MPIR_C_STATUS_IGNORE") :: MPIR_C_STATUS_IGNORE ! Declare the C function prototype to bind function MPIR_Example_c(len, counts, status) result(ierror) BIND(C, name="MPI_Example") integer(c_int), intent(in) :: len integer(c_int), intent(in) :: counts(len) type(c_Status) :: status integer(c_int) :: ierror end function subroutine MPI_Example_f08(len, counts, status, ierror) integer, intent(in) :: len integer, intent(in) :: counts(len) type(MPI_Status) :: status integer, optional :: ierror_c integer(c_int), intent(in) :: len_c integer(c_int), intent(in) :: counts_c(len) type(c_Status) :: status_c integer(c_int) :: ierror_c if (c_int == kind(0) then ! Common case if (c_loc(status) == c_loc(MPI_STATUS_IGNORE)) then ! In C MPI_Example, it will checks again if status is 'IGNORE'. But we have to duplicate the work here due to type difference of MPI_STATUS_IGNORE and MPIR_C_STATUS_IGNORE. ierror = MPIR_Example_c(len, counts, MPIR_C_STATUS_IGNORE) else ! ierror = MPIR_Example_c(len, counts, status) ! Compile error since type(MPI_Status) mismatches type(c_Status) even c_int = INTEGER ierror = MPIR_Example_c(len, counts, status_c) status = status_c ! Note that = is overloaded. Can Compiler optimize away this copy propogation? probably not. endif ! This is bad since MPI_Status and c_Status are indeed the same. Even worse if status is an array. else len_c = len counts_c = counts if (c_loc(status) == c_loc(MPI_STATUS_IGNORE)) then ierror = MPIR_Example_c(len_c, counts_c, MPIR_C_STATUS_IGNORE) else ierror = MPIR_Example_c(len_c, counts_c, status_c) status = status_c endif endif if(present(ierror)) ierror = ierror_c end subroutine However, if I can use c_int in MPI_Status, then MPI_Status and c_Status are the same. I will have type MPI_Status INTEGER(c_int) :: MPI_SOURCE, MPI_ERROR, MPI_TAG ! other fields end type MPI_Status type(MPI_Status), BIND(C, name="MPI_STATUS_IGNORE") :: MPI_STATUS_IGNORE function MPIR_Example_c(len, counts, status) result(ierror) BIND(C, name="MPI_Example") integer(c_int), intent(in) :: len integer(c_int), intent(in) :: counts(len) type(MPI_Status) :: status ! Now use MPI_Status instead of c_Status integer(c_int) :: ierror end function subroutine MPI_Example_f08(len, counts, status, ierror) integer, intent(in) :: len integer, intent(in) :: counts(len) type(MPI_Status) :: status integer, optional :: ierror_c integer(c_int), intent(in) :: len_c integer(c_int), intent(in) :: counts_c(len) integer(c_int) :: ierror_c if (c_int == kind(0) then ierror = MPIR_Example_c(len, counts, status) ! Zero overhead incurred on status. else len_c = len counts_c = counts ierror = MPIR_Example_c(len_c, counts_c, status) endif if(present(ierror)) ierror = ierror_c end subroutine --Junchao Zhang On Sat, Mar 15, 2014 at 7:38 AM, Rolf Rabenseifner <rabenseifner(a)hlrs.de>wrote: > Dear Junchao, > > As long as you use status%MPI_SOURCE in an expression, > all is fine. > > If you pass it to an application routine dummy argument > that is defined as INTEGER and your status%MPI_SOURCE > is define as INTEGER(C_INT) then you may get compiler > warnings or errors if size of both INTEGER types is different. > > CALL foo(status%MPI_SOURCE) > > with > SUBROUTINE foo(rank) > INTEGER :: rank > > Best regards > Rolf > > > ----- Original Message ----- > > From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> > > To: "MPI-WG Fortran working group" mpi-forum.org> > > Sent: Saturday, March 15, 2014 11:54:38 AM > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > > > My point is, with the C_INT implementation of MPI_Status, there > > should be no compilation warnings AND runtime errors, even if > > INTEGER kind is not c_int, since users can only operate MPI_Status > > through their public interfaces, in which we take care of data > > conversion. > > > > > > But for other arguments of type INTEGER or array of INTEGERs, I can > > not change their type. Users pass in an array of INTEGERs, I can not > > pretend they are c_int and don't do conversion. > > > > > > > > --Junchao Zhang > > > > > > On Sat, Mar 15, 2014 at 3:33 AM, Rolf Rabenseifner < > > rabenseifner(a)hlrs.de > wrote: > > > > > > Junchao, > > > > With the erratum ticket #415, your implementation > > with INTEGER(C_INT) is clearly wrong, > > but who cares as long as an application programmer cannot > > write an application code that produces compilation errors > > or warnings or infos due to your wrong implementation > > of TYPE(MPI_Status). > > > > I do not exactly now the rules about Fortran subroutine > > prototype and overloading where handing over a INTEGER rank > > or a INTEGER(C_INT) rank may cause to choose different interfaces. > > > > Maybe that Bill Long should comment on such strange things > > before you define any field within TYPE(MPI_Status) or > > any dummy argument in a routine declaration as INTEGER(C_INT) > > instead of INTEGER as defined in MPI-3.0. > > > > > > Best regards > > Rolf > > > > ----- Original Message ----- > > > From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > > > > > > Sent: Saturday, March 15, 2014 12:11:35 AM > > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > > > > > > > Not sure if it is worth discussing. Even if INTEGER and C_INT are > > > of > > > different size, I think I can still use C_INT in MPI_Status. > > > > > > > > > > > > TYPE, BIND(C) :: MPI_Status > > > INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > > ... ! other fields > > > END TYPE MPI_Status > > > > > > > > > Since MPI_Status is a derived datatype, users access it through its > > > public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). > > > As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), > > > who > > > cares its internals. > > > > > > > > > > > > > > > > > > --Junchao Zhang > > > > > > > > > On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner < > > > rabenseifner(a)hlrs.de > wrote: > > > > > > > > > Jeff is right. > > > Bill's theoretical statement is also correct. > > > > > > And ticket#415 is also correct because it resolves an inconsistency > > > within the mpi_f08 interface. > > > > > > Strange theoretical discussions are also there for > > > long Fortran INTEGER may not be identical with some shorter > > > INTEGER(C_int). > > > As a side effect also solved by this ticket. > > > > > > > > > Rolf > > > > > > ----- Original Message ----- > > > > > > > From: "Jeff Hammond" < jeff.science(a)gmail.com > > > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > > > Sent: Thursday, March 13, 2014 4:12:56 PM > > > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > > > MPI should test for interoperability of Fortran's default integer > > > > and > > > > light the machine room on fire if it is not. > > > > > > > > Jeff > > > > > > > > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long < longb(a)cray.com > > > > > wrote: > > > > > This does raise an earlier issue that it is > > > > > > > > > > > possible that Fortran's default INTEGER is not an interoperable > > > > > type, and thus the MPI_Status type should not be a BIND(C) type > > > > > if > > > > > it has INTEGER components. Having BIND(C) does allow you to > > > > > declare a C global name MPI_STATUS_IGNORE in Fortran, which > > > > > solves > > > > > one problem nicely. I don't see any advantage to having INTEGER > > > > > components (as opposed to INTEGER(C_Int), for example). So this > > > > > seems to represent the worse of the two options. > > > > > > > > > > Cheers, > > > > > Bill > > > > > > > > > > > > > > > > > > > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) > > > > > < jsquyres(a)cisco.com > wrote: > > > > > > > > > >> Done. Good catch: > > > > >> > > > > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 > > > > >> > > > > >> This is a trivial ticket, but if you could make sure it's ok, > > > > >> I'll > > > > >> send it to the mpi-forum list so that it can get added to the > > > > >> next meeting's agenda. > > > > >> > > > > >> > > > > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner > > > > >> < rabenseifner(a)hlrs.de > wrote: > > > > >> > > > > >>> Jeff and Junchao, > > > > >>> > > > > >>> it is a missing word INTEGER in this part of the sentence > > > > >>> > > > > >>> In whole MPI these three values are in Fortran INTEGER and > > > > >>> nothing else > > > > >>> > > > > >>> Junchao, thank you for the hint that an erratum is neede > > > > >>> to prevent from such misinterpretation > > > > >>> > > > > >>> Jeff, please can you file the errata ticket resulting in > > > > >>> > > > > >>> ... containing three public INTEGER fields named ... > > > > >>> > > > > >>> Best regards > > > > >>> Rolf > > > > >>> > > > > >>> > > > > >>> ----- Original Message ----- > > > > >>>> From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > > > >>>> To: "MPI-WG Fortran working group" > > > > > > > > > > >>>> mpi-forum.org > > > > > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM > > > > >>>> Subject: [MPIWG Fortran] Type of MPI_Status > > > > >>>> > > > > >>>> > > > > >>>> > > > > >>>> > > > > >>>> Hello, > > > > >>>> > > > > >>>> > > > > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE > > > > >>>> 'mpif.h', > > > > >>>> status > > > > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With > > > > >>>> Fortran > > > > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) > > > > >>>> derived > > > > >>>> type > > > > >>>> TYPE(MPI_Status) containing three public fields named > > > > >>>> MPI_SOURCE > > > > >>>> , > > > > >>>> MPI_TAG , and MPI_ERROR" > > > > >>>> > > > > >>>> In other words, it does't say type of the three public > > > > >>>> fields > > > > >>>> must be > > > > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as > > > > >>>> > > > > >>>> > > > > >>>> TYPE, BIND(C) :: MPI_Status > > > > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > > > >>>> ... ! other fields > > > > >>>> END TYPE MPI_Status > > > > >>>> > > > > >>>> > > > > >>>> I find it makes MPI_Status binding easier. Since this type > > > > >>>> is > > > > >>>> interoperable with C, I do not need to allocate temp > > > > >>>> variables > > > > >>>> to do > > > > >>>> type conversion when INTEGER is not a C_INT. > > > > >>>> > > > > >>>> > > > > >>>> > > > > >>>> --Junchao Zhang > > > > >>>> _______________________________________________ > > > > >>>> mpiwg-fortran mailing list > > > > >>>> mpiwg-fortran(a)lists.mpi-forum.org > > > > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > >>> > > > > >>> -- > > > > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email > > > > >>> rabenseifner(a)hlrs.de > > > > >>> High Performance Computing Center (HLRS) . phone > > > > >>> ++49(0)711/685-65530 > > > > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > > > >>> 685-65832 > > > > >>> Head of Dpmt Parallel Computing . . . > > > > >>> www.hlrs.de/people/rabenseifner > > > > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: > > > > >>> Room > > > > >>> 1.307) > > > > >>> _______________________________________________ > > > > >>> mpiwg-fortran mailing list > > > > >>> mpiwg-fortran(a)lists.mpi-forum.org > > > > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > >> > > > > >> > > > > >> -- > > > > >> Jeff Squyres > > > > >> jsquyres(a)cisco.com > > > > >> For corporate legal information go to: > > > > >> http://www.cisco.com/web/about/doing_business/legal/cri/ > > > > >> > > > > >> _______________________________________________ > > > > >> mpiwg-fortran mailing list > > > > >> mpiwg-fortran(a)lists.mpi-forum.org > > > > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > > > Bill Long > > > > > longb(a)cray.com > > > > > Fortran Technical Suport & voice: > > > > > 651-605-9024 > > > > > Bioinformatics Software Development fax: > > > > > 651-605-9142 > > > > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN > > > > > 55101 > > > > > > > > > > > > > > > _______________________________________________ > > > > > mpiwg-fortran mailing list > > > > > mpiwg-fortran(a)lists.mpi-forum.org > > > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > > > > > > > > > -- > > > > Jeff Hammond > > > > jeff.science(a)gmail.com > > > > _______________________________________________ > > > > mpiwg-fortran mailing list > > > > mpiwg-fortran(a)lists.mpi-forum.org > > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > -- > > > Dr. Rolf Rabenseifner . . . . . . . . . .. email > > > rabenseifner(a)hlrs.de > > > High Performance Computing Center (HLRS) . phone > > > ++49(0)711/685-65530 > > > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > > 685-65832 > > > Head of Dpmt Parallel Computing . . . > > > www.hlrs.de/people/rabenseifner > > > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > > > 1.307) > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > -- > > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > -- > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >

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Re: [MPIWG Fortran] Type of MPI_Status
by Rolf Rabenseifner 15 Mar '14

15 Mar '14

Dear Junchao, As long as you use status%MPI_SOURCE in an expression, all is fine. If you pass it to an application routine dummy argument that is defined as INTEGER and your status%MPI_SOURCE is define as INTEGER(C_INT) then you may get compiler warnings or errors if size of both INTEGER types is different. CALL foo(status%MPI_SOURCE) with SUBROUTINE foo(rank) INTEGER :: rank Best regards Rolf ----- Original Message ----- > From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> > To: "MPI-WG Fortran working group" mpi-forum.org> > Sent: Saturday, March 15, 2014 11:54:38 AM > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > My point is, with the C_INT implementation of MPI_Status, there > should be no compilation warnings AND runtime errors, even if > INTEGER kind is not c_int, since users can only operate MPI_Status > through their public interfaces, in which we take care of data > conversion. > > > But for other arguments of type INTEGER or array of INTEGERs, I can > not change their type. Users pass in an array of INTEGERs, I can not > pretend they are c_int and don't do conversion. > > > > --Junchao Zhang > > > On Sat, Mar 15, 2014 at 3:33 AM, Rolf Rabenseifner < > rabenseifner(a)hlrs.de > wrote: > > > Junchao, > > With the erratum ticket #415, your implementation > with INTEGER(C_INT) is clearly wrong, > but who cares as long as an application programmer cannot > write an application code that produces compilation errors > or warnings or infos due to your wrong implementation > of TYPE(MPI_Status). > > I do not exactly now the rules about Fortran subroutine > prototype and overloading where handing over a INTEGER rank > or a INTEGER(C_INT) rank may cause to choose different interfaces. > > Maybe that Bill Long should comment on such strange things > before you define any field within TYPE(MPI_Status) or > any dummy argument in a routine declaration as INTEGER(C_INT) > instead of INTEGER as defined in MPI-3.0. > > > Best regards > Rolf > > ----- Original Message ----- > > From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > > > Sent: Saturday, March 15, 2014 12:11:35 AM > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > > > Not sure if it is worth discussing. Even if INTEGER and C_INT are > > of > > different size, I think I can still use C_INT in MPI_Status. > > > > > > > > TYPE, BIND(C) :: MPI_Status > > INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > ... ! other fields > > END TYPE MPI_Status > > > > > > Since MPI_Status is a derived datatype, users access it through its > > public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). > > As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), > > who > > cares its internals. > > > > > > > > > > > > --Junchao Zhang > > > > > > On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner < > > rabenseifner(a)hlrs.de > wrote: > > > > > > Jeff is right. > > Bill's theoretical statement is also correct. > > > > And ticket#415 is also correct because it resolves an inconsistency > > within the mpi_f08 interface. > > > > Strange theoretical discussions are also there for > > long Fortran INTEGER may not be identical with some shorter > > INTEGER(C_int). > > As a side effect also solved by this ticket. > > > > > > Rolf > > > > ----- Original Message ----- > > > > > From: "Jeff Hammond" < jeff.science(a)gmail.com > > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > > Sent: Thursday, March 13, 2014 4:12:56 PM > > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > MPI should test for interoperability of Fortran's default integer > > > and > > > light the machine room on fire if it is not. > > > > > > Jeff > > > > > > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long < longb(a)cray.com > > > > wrote: > > > > This does raise an earlier issue that it is > > > > > > > > possible that Fortran’s default INTEGER is not an interoperable > > > > type, and thus the MPI_Status type should not be a BIND(C) type > > > > if > > > > it has INTEGER components. Having BIND(C) does allow you to > > > > declare a C global name MPI_STATUS_IGNORE in Fortran, which > > > > solves > > > > one problem nicely. I don’t see any advantage to having INTEGER > > > > components (as opposed to INTEGER(C_Int), for example). So this > > > > seems to represent the worse of the two options. > > > > > > > > Cheers, > > > > Bill > > > > > > > > > > > > > > > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) > > > > < jsquyres(a)cisco.com > wrote: > > > > > > > >> Done. Good catch: > > > >> > > > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 > > > >> > > > >> This is a trivial ticket, but if you could make sure it's ok, > > > >> I'll > > > >> send it to the mpi-forum list so that it can get added to the > > > >> next meeting's agenda. > > > >> > > > >> > > > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner > > > >> < rabenseifner(a)hlrs.de > wrote: > > > >> > > > >>> Jeff and Junchao, > > > >>> > > > >>> it is a missing word INTEGER in this part of the sentence > > > >>> > > > >>> In whole MPI these three values are in Fortran INTEGER and > > > >>> nothing else > > > >>> > > > >>> Junchao, thank you for the hint that an erratum is neede > > > >>> to prevent from such misinterpretation > > > >>> > > > >>> Jeff, please can you file the errata ticket resulting in > > > >>> > > > >>> ... containing three public INTEGER fields named ... > > > >>> > > > >>> Best regards > > > >>> Rolf > > > >>> > > > >>> > > > >>> ----- Original Message ----- > > > >>>> From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > > >>>> To: "MPI-WG Fortran working group" > > > > > > > >>>> mpi-forum.org > > > > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM > > > >>>> Subject: [MPIWG Fortran] Type of MPI_Status > > > >>>> > > > >>>> > > > >>>> > > > >>>> > > > >>>> Hello, > > > >>>> > > > >>>> > > > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE > > > >>>> ’mpif.h’, > > > >>>> status > > > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With > > > >>>> Fortran > > > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) > > > >>>> derived > > > >>>> type > > > >>>> TYPE(MPI_Status) containing three public fields named > > > >>>> MPI_SOURCE > > > >>>> , > > > >>>> MPI_TAG , and MPI_ERROR" > > > >>>> > > > >>>> In other words, it does't say type of the three public > > > >>>> fields > > > >>>> must be > > > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as > > > >>>> > > > >>>> > > > >>>> TYPE, BIND(C) :: MPI_Status > > > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > > >>>> ... ! other fields > > > >>>> END TYPE MPI_Status > > > >>>> > > > >>>> > > > >>>> I find it makes MPI_Status binding easier. Since this type > > > >>>> is > > > >>>> interoperable with C, I do not need to allocate temp > > > >>>> variables > > > >>>> to do > > > >>>> type conversion when INTEGER is not a C_INT. > > > >>>> > > > >>>> > > > >>>> > > > >>>> --Junchao Zhang > > > >>>> _______________________________________________ > > > >>>> mpiwg-fortran mailing list > > > >>>> mpiwg-fortran(a)lists.mpi-forum.org > > > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > >>> > > > >>> -- > > > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email > > > >>> rabenseifner(a)hlrs.de > > > >>> High Performance Computing Center (HLRS) . phone > > > >>> ++49(0)711/685-65530 > > > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > > >>> 685-65832 > > > >>> Head of Dpmt Parallel Computing . . . > > > >>> www.hlrs.de/people/rabenseifner > > > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: > > > >>> Room > > > >>> 1.307) > > > >>> _______________________________________________ > > > >>> mpiwg-fortran mailing list > > > >>> mpiwg-fortran(a)lists.mpi-forum.org > > > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > >> > > > >> > > > >> -- > > > >> Jeff Squyres > > > >> jsquyres(a)cisco.com > > > >> For corporate legal information go to: > > > >> http://www.cisco.com/web/about/doing_business/legal/cri/ > > > >> > > > >> _______________________________________________ > > > >> mpiwg-fortran mailing list > > > >> mpiwg-fortran(a)lists.mpi-forum.org > > > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > Bill Long > > > > longb(a)cray.com > > > > Fortran Technical Suport & voice: > > > > 651-605-9024 > > > > Bioinformatics Software Development fax: > > > > 651-605-9142 > > > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN > > > > 55101 > > > > > > > > > > > > _______________________________________________ > > > > mpiwg-fortran mailing list > > > > mpiwg-fortran(a)lists.mpi-forum.org > > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > > > > > -- > > > Jeff Hammond > > > jeff.science(a)gmail.com > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > -- > > Dr. Rolf Rabenseifner . . . . . . . . . .. email > > rabenseifner(a)hlrs.de > > High Performance Computing Center (HLRS) . phone > > ++49(0)711/685-65530 > > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > 685-65832 > > Head of Dpmt Parallel Computing . . . > > www.hlrs.de/people/rabenseifner > > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > > 1.307) > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > -- > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran -- Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307)

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Re: [MPIWG Fortran] Type of MPI_Status
by Junchao Zhang 15 Mar '14

15 Mar '14

My point is, with the C_INT implementation of MPI_Status, there should be no compilation warnings AND runtime errors, even if INTEGER kind is not c_int, since users can only operate MPI_Status through their public interfaces, in which we take care of data conversion. But for other arguments of type INTEGER or array of INTEGERs, I can not change their type. Users pass in an array of INTEGERs, I can not pretend they are c_int and don't do conversion. --Junchao Zhang On Sat, Mar 15, 2014 at 3:33 AM, Rolf Rabenseifner <rabenseifner(a)hlrs.de>wrote: > Junchao, > > With the erratum ticket #415, your implementation > with INTEGER(C_INT) is clearly wrong, > but who cares as long as an application programmer cannot > write an application code that produces compilation errors > or warnings or infos due to your wrong implementation > of TYPE(MPI_Status). > > I do not exactly now the rules about Fortran subroutine > prototype and overloading where handing over a INTEGER rank > or a INTEGER(C_INT) rank may cause to choose different interfaces. > > Maybe that Bill Long should comment on such strange things > before you define any field within TYPE(MPI_Status) or > any dummy argument in a routine declaration as INTEGER(C_INT) > instead of INTEGER as defined in MPI-3.0. > > Best regards > Rolf > > ----- Original Message ----- > > From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> > > To: "MPI-WG Fortran working group" mpi-forum.org> > > Sent: Saturday, March 15, 2014 12:11:35 AM > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > > > Not sure if it is worth discussing. Even if INTEGER and C_INT are of > > different size, I think I can still use C_INT in MPI_Status. > > > > > > > > TYPE, BIND(C) :: MPI_Status > > INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > ... ! other fields > > END TYPE MPI_Status > > > > > > Since MPI_Status is a derived datatype, users access it through its > > public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). > > As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), who > > cares its internals. > > > > > > > > > > > > --Junchao Zhang > > > > > > On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner < > > rabenseifner(a)hlrs.de > wrote: > > > > > > Jeff is right. > > Bill's theoretical statement is also correct. > > > > And ticket#415 is also correct because it resolves an inconsistency > > within the mpi_f08 interface. > > > > Strange theoretical discussions are also there for > > long Fortran INTEGER may not be identical with some shorter > > INTEGER(C_int). > > As a side effect also solved by this ticket. > > > > > > Rolf > > > > ----- Original Message ----- > > > > > From: "Jeff Hammond" < jeff.science(a)gmail.com > > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > > Sent: Thursday, March 13, 2014 4:12:56 PM > > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > > > MPI should test for interoperability of Fortran's default integer > > > and > > > light the machine room on fire if it is not. > > > > > > Jeff > > > > > > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long < longb(a)cray.com > > > > wrote: > > > > This does raise an earlier issue that it is > > > > > > > > possible that Fortran's default INTEGER is not an interoperable > > > > type, and thus the MPI_Status type should not be a BIND(C) type > > > > if > > > > it has INTEGER components. Having BIND(C) does allow you to > > > > declare a C global name MPI_STATUS_IGNORE in Fortran, which > > > > solves > > > > one problem nicely. I don't see any advantage to having INTEGER > > > > components (as opposed to INTEGER(C_Int), for example). So this > > > > seems to represent the worse of the two options. > > > > > > > > Cheers, > > > > Bill > > > > > > > > > > > > > > > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) > > > > < jsquyres(a)cisco.com > wrote: > > > > > > > >> Done. Good catch: > > > >> > > > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 > > > >> > > > >> This is a trivial ticket, but if you could make sure it's ok, > > > >> I'll > > > >> send it to the mpi-forum list so that it can get added to the > > > >> next meeting's agenda. > > > >> > > > >> > > > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner > > > >> < rabenseifner(a)hlrs.de > wrote: > > > >> > > > >>> Jeff and Junchao, > > > >>> > > > >>> it is a missing word INTEGER in this part of the sentence > > > >>> > > > >>> In whole MPI these three values are in Fortran INTEGER and > > > >>> nothing else > > > >>> > > > >>> Junchao, thank you for the hint that an erratum is neede > > > >>> to prevent from such misinterpretation > > > >>> > > > >>> Jeff, please can you file the errata ticket resulting in > > > >>> > > > >>> ... containing three public INTEGER fields named ... > > > >>> > > > >>> Best regards > > > >>> Rolf > > > >>> > > > >>> > > > >>> ----- Original Message ----- > > > >>>> From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > > >>>> To: "MPI-WG Fortran working group" > > > > > > > >>>> mpi-forum.org > > > > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM > > > >>>> Subject: [MPIWG Fortran] Type of MPI_Status > > > >>>> > > > >>>> > > > >>>> > > > >>>> > > > >>>> Hello, > > > >>>> > > > >>>> > > > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE 'mpif.h', > > > >>>> status > > > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With > > > >>>> Fortran > > > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) derived > > > >>>> type > > > >>>> TYPE(MPI_Status) containing three public fields named > > > >>>> MPI_SOURCE > > > >>>> , > > > >>>> MPI_TAG , and MPI_ERROR" > > > >>>> > > > >>>> In other words, it does't say type of the three public fields > > > >>>> must be > > > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as > > > >>>> > > > >>>> > > > >>>> TYPE, BIND(C) :: MPI_Status > > > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > > >>>> ... ! other fields > > > >>>> END TYPE MPI_Status > > > >>>> > > > >>>> > > > >>>> I find it makes MPI_Status binding easier. Since this type is > > > >>>> interoperable with C, I do not need to allocate temp variables > > > >>>> to do > > > >>>> type conversion when INTEGER is not a C_INT. > > > >>>> > > > >>>> > > > >>>> > > > >>>> --Junchao Zhang > > > >>>> _______________________________________________ > > > >>>> mpiwg-fortran mailing list > > > >>>> mpiwg-fortran(a)lists.mpi-forum.org > > > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > >>> > > > >>> -- > > > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email > > > >>> rabenseifner(a)hlrs.de > > > >>> High Performance Computing Center (HLRS) . phone > > > >>> ++49(0)711/685-65530 > > > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > > >>> 685-65832 > > > >>> Head of Dpmt Parallel Computing . . . > > > >>> www.hlrs.de/people/rabenseifner > > > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > > > >>> 1.307) > > > >>> _______________________________________________ > > > >>> mpiwg-fortran mailing list > > > >>> mpiwg-fortran(a)lists.mpi-forum.org > > > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > >> > > > >> > > > >> -- > > > >> Jeff Squyres > > > >> jsquyres(a)cisco.com > > > >> For corporate legal information go to: > > > >> http://www.cisco.com/web/about/doing_business/legal/cri/ > > > >> > > > >> _______________________________________________ > > > >> mpiwg-fortran mailing list > > > >> mpiwg-fortran(a)lists.mpi-forum.org > > > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > Bill Long > > > > longb(a)cray.com > > > > Fortran Technical Suport & voice: > > > > 651-605-9024 > > > > Bioinformatics Software Development fax: > > > > 651-605-9142 > > > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN > > > > 55101 > > > > > > > > > > > > _______________________________________________ > > > > mpiwg-fortran mailing list > > > > mpiwg-fortran(a)lists.mpi-forum.org > > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > > > > > -- > > > Jeff Hammond > > > jeff.science(a)gmail.com > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > -- > > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > -- > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >

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Re: [MPIWG Fortran] Type of MPI_Status
by Rolf Rabenseifner 15 Mar '14

15 Mar '14

Junchao, With the erratum ticket #415, your implementation with INTEGER(C_INT) is clearly wrong, but who cares as long as an application programmer cannot write an application code that produces compilation errors or warnings or infos due to your wrong implementation of TYPE(MPI_Status). I do not exactly now the rules about Fortran subroutine prototype and overloading where handing over a INTEGER rank or a INTEGER(C_INT) rank may cause to choose different interfaces. Maybe that Bill Long should comment on such strange things before you define any field within TYPE(MPI_Status) or any dummy argument in a routine declaration as INTEGER(C_INT) instead of INTEGER as defined in MPI-3.0. Best regards Rolf ----- Original Message ----- > From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> > To: "MPI-WG Fortran working group" mpi-forum.org> > Sent: Saturday, March 15, 2014 12:11:35 AM > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > Not sure if it is worth discussing. Even if INTEGER and C_INT are of > different size, I think I can still use C_INT in MPI_Status. > > > > TYPE, BIND(C) :: MPI_Status > INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > ... ! other fields > END TYPE MPI_Status > > > Since MPI_Status is a derived datatype, users access it through its > public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). > As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), who > cares its internals. > > > > > > --Junchao Zhang > > > On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner < > rabenseifner(a)hlrs.de > wrote: > > > Jeff is right. > Bill's theoretical statement is also correct. > > And ticket#415 is also correct because it resolves an inconsistency > within the mpi_f08 interface. > > Strange theoretical discussions are also there for > long Fortran INTEGER may not be identical with some shorter > INTEGER(C_int). > As a side effect also solved by this ticket. > > > Rolf > > ----- Original Message ----- > > > From: "Jeff Hammond" < jeff.science(a)gmail.com > > > To: "MPI-WG Fortran working group" mpi-forum.org > > > Sent: Thursday, March 13, 2014 4:12:56 PM > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > MPI should test for interoperability of Fortran's default integer > > and > > light the machine room on fire if it is not. > > > > Jeff > > > > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long < longb(a)cray.com > > > wrote: > > > This does raise an earlier issue that it is > > > > > possible that Fortran’s default INTEGER is not an interoperable > > > type, and thus the MPI_Status type should not be a BIND(C) type > > > if > > > it has INTEGER components. Having BIND(C) does allow you to > > > declare a C global name MPI_STATUS_IGNORE in Fortran, which > > > solves > > > one problem nicely. I don’t see any advantage to having INTEGER > > > components (as opposed to INTEGER(C_Int), for example). So this > > > seems to represent the worse of the two options. > > > > > > Cheers, > > > Bill > > > > > > > > > > > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) > > > < jsquyres(a)cisco.com > wrote: > > > > > >> Done. Good catch: > > >> > > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 > > >> > > >> This is a trivial ticket, but if you could make sure it's ok, > > >> I'll > > >> send it to the mpi-forum list so that it can get added to the > > >> next meeting's agenda. > > >> > > >> > > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner > > >> < rabenseifner(a)hlrs.de > wrote: > > >> > > >>> Jeff and Junchao, > > >>> > > >>> it is a missing word INTEGER in this part of the sentence > > >>> > > >>> In whole MPI these three values are in Fortran INTEGER and > > >>> nothing else > > >>> > > >>> Junchao, thank you for the hint that an erratum is neede > > >>> to prevent from such misinterpretation > > >>> > > >>> Jeff, please can you file the errata ticket resulting in > > >>> > > >>> ... containing three public INTEGER fields named ... > > >>> > > >>> Best regards > > >>> Rolf > > >>> > > >>> > > >>> ----- Original Message ----- > > >>>> From: "Junchao Zhang" < jczhang(a)mcs.anl.gov > > > >>>> To: "MPI-WG Fortran working group" > > > > >>>> mpi-forum.org > > > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM > > >>>> Subject: [MPIWG Fortran] Type of MPI_Status > > >>>> > > >>>> > > >>>> > > >>>> > > >>>> Hello, > > >>>> > > >>>> > > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE ’mpif.h’, > > >>>> status > > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With > > >>>> Fortran > > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) derived > > >>>> type > > >>>> TYPE(MPI_Status) containing three public fields named > > >>>> MPI_SOURCE > > >>>> , > > >>>> MPI_TAG , and MPI_ERROR" > > >>>> > > >>>> In other words, it does't say type of the three public fields > > >>>> must be > > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as > > >>>> > > >>>> > > >>>> TYPE, BIND(C) :: MPI_Status > > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > >>>> ... ! other fields > > >>>> END TYPE MPI_Status > > >>>> > > >>>> > > >>>> I find it makes MPI_Status binding easier. Since this type is > > >>>> interoperable with C, I do not need to allocate temp variables > > >>>> to do > > >>>> type conversion when INTEGER is not a C_INT. > > >>>> > > >>>> > > >>>> > > >>>> --Junchao Zhang > > >>>> _______________________________________________ > > >>>> mpiwg-fortran mailing list > > >>>> mpiwg-fortran(a)lists.mpi-forum.org > > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > >>> > > >>> -- > > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email > > >>> rabenseifner(a)hlrs.de > > >>> High Performance Computing Center (HLRS) . phone > > >>> ++49(0)711/685-65530 > > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > >>> 685-65832 > > >>> Head of Dpmt Parallel Computing . . . > > >>> www.hlrs.de/people/rabenseifner > > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > > >>> 1.307) > > >>> _______________________________________________ > > >>> mpiwg-fortran mailing list > > >>> mpiwg-fortran(a)lists.mpi-forum.org > > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > >> > > >> > > >> -- > > >> Jeff Squyres > > >> jsquyres(a)cisco.com > > >> For corporate legal information go to: > > >> http://www.cisco.com/web/about/doing_business/legal/cri/ > > >> > > >> _______________________________________________ > > >> mpiwg-fortran mailing list > > >> mpiwg-fortran(a)lists.mpi-forum.org > > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > Bill Long > > > longb(a)cray.com > > > Fortran Technical Suport & voice: > > > 651-605-9024 > > > Bioinformatics Software Development fax: > > > 651-605-9142 > > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN > > > 55101 > > > > > > > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > -- > > Jeff Hammond > > jeff.science(a)gmail.com > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > -- > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran -- Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307)

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Re: [MPIWG Fortran] Type of MPI_Status
by Junchao Zhang 14 Mar '14

14 Mar '14

Not sure if it is worth discussing. Even if INTEGER and C_INT are of different size, I think I can still use C_INT in MPI_Status. TYPE, BIND(C) :: MPI_Status INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR ... ! other fields END TYPE MPI_Status Since MPI_Status is a derived datatype, users access it through its public interfaces(i.e., %MPI_SOURCE, ..., MPI_STATUS_SIZE). As long as MPI_STATUS_SIZE >= sizeof(MPI_STATUS)/sizeof(INTEGER), who cares its internals. --Junchao Zhang On Thu, Mar 13, 2014 at 10:56 AM, Rolf Rabenseifner <rabenseifner(a)hlrs.de>wrote: > Jeff is right. > Bill's theoretical statement is also correct. > > And ticket#415 is also correct because it resolves an inconsistency > within the mpi_f08 interface. > > Strange theoretical discussions are also there for > long Fortran INTEGER may not be identical with some shorter INTEGER(C_int). > As a side effect also solved by this ticket. > > Rolf > > ----- Original Message ----- > > From: "Jeff Hammond" <jeff.science(a)gmail.com> > > To: "MPI-WG Fortran working group" mpi-forum.org> > > Sent: Thursday, March 13, 2014 4:12:56 PM > > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > > > MPI should test for interoperability of Fortran's default integer and > > light the machine room on fire if it is not. > > > > Jeff > > > > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long <longb(a)cray.com> wrote: > > > This does raise an earlier issue that it is > > > possible that Fortran's default INTEGER is not an interoperable > > > type, and thus the MPI_Status type should not be a BIND(C) type if > > > it has INTEGER components. Having BIND(C) does allow you to > > > declare a C global name MPI_STATUS_IGNORE in Fortran, which solves > > > one problem nicely. I don't see any advantage to having INTEGER > > > components (as opposed to INTEGER(C_Int), for example). So this > > > seems to represent the worse of the two options. > > > > > > Cheers, > > > Bill > > > > > > > > > > > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) > > > <jsquyres(a)cisco.com> wrote: > > > > > >> Done. Good catch: > > >> > > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 > > >> > > >> This is a trivial ticket, but if you could make sure it's ok, I'll > > >> send it to the mpi-forum list so that it can get added to the > > >> next meeting's agenda. > > >> > > >> > > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner > > >> <rabenseifner(a)hlrs.de> wrote: > > >> > > >>> Jeff and Junchao, > > >>> > > >>> it is a missing word INTEGER in this part of the sentence > > >>> > > >>> In whole MPI these three values are in Fortran INTEGER and > > >>> nothing else > > >>> > > >>> Junchao, thank you for the hint that an erratum is neede > > >>> to prevent from such misinterpretation > > >>> > > >>> Jeff, please can you file the errata ticket resulting in > > >>> > > >>> ... containing three public INTEGER fields named ... > > >>> > > >>> Best regards > > >>> Rolf > > >>> > > >>> > > >>> ----- Original Message ----- > > >>>> From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> > > >>>> To: "MPI-WG Fortran working group" > > >>>> mpi-forum.org> > > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM > > >>>> Subject: [MPIWG Fortran] Type of MPI_Status > > >>>> > > >>>> > > >>>> > > >>>> > > >>>> Hello, > > >>>> > > >>>> > > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE 'mpif.h', > > >>>> status > > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With > > >>>> Fortran > > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) derived > > >>>> type > > >>>> TYPE(MPI_Status) containing three public fields named MPI_SOURCE > > >>>> , > > >>>> MPI_TAG , and MPI_ERROR" > > >>>> > > >>>> In other words, it does't say type of the three public fields > > >>>> must be > > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as > > >>>> > > >>>> > > >>>> TYPE, BIND(C) :: MPI_Status > > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > > >>>> ... ! other fields > > >>>> END TYPE MPI_Status > > >>>> > > >>>> > > >>>> I find it makes MPI_Status binding easier. Since this type is > > >>>> interoperable with C, I do not need to allocate temp variables > > >>>> to do > > >>>> type conversion when INTEGER is not a C_INT. > > >>>> > > >>>> > > >>>> > > >>>> --Junchao Zhang > > >>>> _______________________________________________ > > >>>> mpiwg-fortran mailing list > > >>>> mpiwg-fortran(a)lists.mpi-forum.org > > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > >>> > > >>> -- > > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email > > >>> rabenseifner(a)hlrs.de > > >>> High Performance Computing Center (HLRS) . phone > > >>> ++49(0)711/685-65530 > > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > > >>> 685-65832 > > >>> Head of Dpmt Parallel Computing . . . > > >>> www.hlrs.de/people/rabenseifner > > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > > >>> 1.307) > > >>> _______________________________________________ > > >>> mpiwg-fortran mailing list > > >>> mpiwg-fortran(a)lists.mpi-forum.org > > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > >> > > >> > > >> -- > > >> Jeff Squyres > > >> jsquyres(a)cisco.com > > >> For corporate legal information go to: > > >> http://www.cisco.com/web/about/doing_business/legal/cri/ > > >> > > >> _______________________________________________ > > >> mpiwg-fortran mailing list > > >> mpiwg-fortran(a)lists.mpi-forum.org > > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > Bill Long > > > > longb(a)cray.com > > > Fortran Technical Suport & voice: > > > 651-605-9024 > > > Bioinformatics Software Development fax: > > > 651-605-9142 > > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN > > > 55101 > > > > > > > > > _______________________________________________ > > > mpiwg-fortran mailing list > > > mpiwg-fortran(a)lists.mpi-forum.org > > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > > > > > -- > > Jeff Hammond > > jeff.science(a)gmail.com > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > -- > Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de > High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 > University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 > Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner > Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307) > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran >

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Re: [MPIWG Fortran] Type of MPI_Status
by Rolf Rabenseifner 13 Mar '14

13 Mar '14

Jeff is right. Bill's theoretical statement is also correct. And ticket#415 is also correct because it resolves an inconsistency within the mpi_f08 interface. Strange theoretical discussions are also there for long Fortran INTEGER may not be identical with some shorter INTEGER(C_int). As a side effect also solved by this ticket. Rolf ----- Original Message ----- > From: "Jeff Hammond" <jeff.science(a)gmail.com> > To: "MPI-WG Fortran working group" mpi-forum.org> > Sent: Thursday, March 13, 2014 4:12:56 PM > Subject: Re: [MPIWG Fortran] Type of MPI_Status > > MPI should test for interoperability of Fortran's default integer and > light the machine room on fire if it is not. > > Jeff > > On Thu, Mar 13, 2014 at 8:58 AM, Bill Long <longb(a)cray.com> wrote: > > This does raise an earlier issue that it is > > possible that Fortran’s default INTEGER is not an interoperable > > type, and thus the MPI_Status type should not be a BIND(C) type if > > it has INTEGER components. Having BIND(C) does allow you to > > declare a C global name MPI_STATUS_IGNORE in Fortran, which solves > > one problem nicely. I don’t see any advantage to having INTEGER > > components (as opposed to INTEGER(C_Int), for example). So this > > seems to represent the worse of the two options. > > > > Cheers, > > Bill > > > > > > > > On Mar 13, 2014, at 8:36 AM, Jeff Squyres (jsquyres) > > <jsquyres(a)cisco.com> wrote: > > > >> Done. Good catch: > >> > >> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/415 > >> > >> This is a trivial ticket, but if you could make sure it's ok, I'll > >> send it to the mpi-forum list so that it can get added to the > >> next meeting's agenda. > >> > >> > >> On Mar 13, 2014, at 1:51 AM, Rolf Rabenseifner > >> <rabenseifner(a)hlrs.de> wrote: > >> > >>> Jeff and Junchao, > >>> > >>> it is a missing word INTEGER in this part of the sentence > >>> > >>> In whole MPI these three values are in Fortran INTEGER and > >>> nothing else > >>> > >>> Junchao, thank you for the hint that an erratum is neede > >>> to prevent from such misinterpretation > >>> > >>> Jeff, please can you file the errata ticket resulting in > >>> > >>> ... containing three public INTEGER fields named ... > >>> > >>> Best regards > >>> Rolf > >>> > >>> > >>> ----- Original Message ----- > >>>> From: "Junchao Zhang" <jczhang(a)mcs.anl.gov> > >>>> To: "MPI-WG Fortran working group" > >>>> mpi-forum.org> > >>>> Sent: Thursday, March 13, 2014 4:49:49 AM > >>>> Subject: [MPIWG Fortran] Type of MPI_Status > >>>> > >>>> > >>>> > >>>> > >>>> Hello, > >>>> > >>>> > >>>> p30 of MPI3 says "In Fortran with USE mpi or INCLUDE ’mpif.h’, > >>>> status > >>>> is an array of INTEGERs of size MPI_STATUS_SIZE. ..., With > >>>> Fortran > >>>> USE mpi_f08, status is defined as the Fortran BIND(C) derived > >>>> type > >>>> TYPE(MPI_Status) containing three public fields named MPI_SOURCE > >>>> , > >>>> MPI_TAG , and MPI_ERROR" > >>>> > >>>> In other words, it does't say type of the three public fields > >>>> must be > >>>> INTEGER. So, in mpi_f08, can I declare MPI_Status as > >>>> > >>>> > >>>> TYPE, BIND(C) :: MPI_Status > >>>> INTEGER(C_INT) :: MPI_SOURCE, MPI_TAG, MPI_ERROR > >>>> ... ! other fields > >>>> END TYPE MPI_Status > >>>> > >>>> > >>>> I find it makes MPI_Status binding easier. Since this type is > >>>> interoperable with C, I do not need to allocate temp variables > >>>> to do > >>>> type conversion when INTEGER is not a C_INT. > >>>> > >>>> > >>>> > >>>> --Junchao Zhang > >>>> _______________________________________________ > >>>> mpiwg-fortran mailing list > >>>> mpiwg-fortran(a)lists.mpi-forum.org > >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > >>> > >>> -- > >>> Dr. Rolf Rabenseifner . . . . . . . . . .. email > >>> rabenseifner(a)hlrs.de > >>> High Performance Computing Center (HLRS) . phone > >>> ++49(0)711/685-65530 > >>> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / > >>> 685-65832 > >>> Head of Dpmt Parallel Computing . . . > >>> www.hlrs.de/people/rabenseifner > >>> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room > >>> 1.307) > >>> _______________________________________________ > >>> mpiwg-fortran mailing list > >>> mpiwg-fortran(a)lists.mpi-forum.org > >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > >> > >> > >> -- > >> Jeff Squyres > >> jsquyres(a)cisco.com > >> For corporate legal information go to: > >> http://www.cisco.com/web/about/doing_business/legal/cri/ > >> > >> _______________________________________________ > >> mpiwg-fortran mailing list > >> mpiwg-fortran(a)lists.mpi-forum.org > >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > Bill Long > > longb(a)cray.com > > Fortran Technical Suport & voice: > > 651-605-9024 > > Bioinformatics Software Development fax: > > 651-605-9142 > > Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN > > 55101 > > > > > > _______________________________________________ > > mpiwg-fortran mailing list > > mpiwg-fortran(a)lists.mpi-forum.org > > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran > > > > -- > Jeff Hammond > jeff.science(a)gmail.com > _______________________________________________ > mpiwg-fortran mailing list > mpiwg-fortran(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran -- Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner(a)hlrs.de High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307)

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