You should probably ask on the MPICH mailing list -- this is the mailing list for the general MPI Forum itself. On May 27, 2012, at 10:42 AM, ���� �� wrote:

when I read mpich2-1.4.1 code, I saw code as follow:

Code: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 typedef int MPI_Datatype; #define MPI_CHAR ((MPI_Datatype)0x4c000101) #define MPI_SIGNED_CHAR ((MPI_Datatype)0x4c000118) #define MPI_UNSIGNED_CHAR ((MPI_Datatype)0x4c000102) #define MPI_BYTE ((MPI_Datatype)0x4c00010d) #define MPI_WCHAR ((MPI_Datatype)0x4c00040e) #define MPI_SHORT ((MPI_Datatype)0x4c000203) #define MPI_UNSIGNED_SHORT ((MPI_Datatype)0x4c000204) #define MPI_INT ((MPI_Datatype)0x4c000405) #define MPI_UNSIGNED ((MPI_Datatype)0x4c000406) #define MPI_LONG ((MPI_Datatype)0x4c000407) #define MPI_UNSIGNED_LONG ((MPI_Datatype)0x4c000408) #define MPI_FLOAT ((MPI_Datatype)0x4c00040a) #define MPI_DOUBLE ((MPI_Datatype)0x4c00080b) #define MPI_LONG_DOUBLE ((MPI_Datatype)0x4c000c0c) #define MPI_LONG_LONG_INT ((MPI_Datatype)0x4c000809) #define MPI_UNSIGNED_LONG_LONG ((MPI_Datatype)0x4c000819) #define MPI_LONG_LONG MPI_LONG_LONG_INT

Anyone can tell me what is the meaning of those hex values? and why does the author use them? why do they define "MPI_CHAR" as ((MPI_Datatype)0x4c000101) instead of "char"? thx _______________________________________________ mpi-forum mailing list [email protected] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum

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