Hi Wei-keng. I've recorded this as http://trac.mpich.org/projects/mpich/ticket/2219 ==rob On 01/14/2015 02:47 PM, Wei-keng Liao wrote:

Attached program is an implementation of example 4.6 from MPI-3 standard. It prints the lower bound, upper bound, extent, size, etc. of a datatype created by MPI_Type_create_struct(). The value of lower bound is incorrect.

Here is the description of example 4.6.

Let type1 have type map, {(double, 0), (char, 8)}, with extent 16. Let B = (2, 1, 3), D = (0, 16, 26), and T = (MPI_FLOAT, type1, MPI_CHAR). Then a call to MPI_TYPE_CREATE_STRUCT(3, B, D, T, newtype) returns a datatype with type map, {(float, 0), (float, 4), (double, 16), (char, 24), (char, 26), (char, 27), (char, 28)}.

According to the type map of "newtype", its LB should be 0, but the result from MPICH gives 16. Rajeev believes this is because of the LB of a resized type was mistakenly carried over to the successive call to MPI_Type_create_struct().

-- Rob Latham Mathematics and Computer Science Division Argonne National Lab, IL USA _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss