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<div class="PlainText">After a discussion with Rajeev and Rob, we found that the deprecated MPI_LB and MPI_UB<br>
markers are still being used in the implementation of MPI_Type_create_subarray() and/or darray.<br>
These markers were mistakenly carried over in MPI_Type_create_struct() causing an incorrect<br>
lower bound for the newly created datatype. A test program that can reproduce the error is<br>
attached. Below is its description.<br>
<br>
The test program tries to concatenate two data types.<br>
The first datatype is a contiguous space of 16 bytes at displacement 0.<br>
The second is a subarray type at displacement 32, named bodytype created by MPI_Type_create_subarray().<br>
The global array is 5*nprocs integers and subarray is of size 5 integers.<br>
<br>
The two types were concatenated by MPI_Type_create_struct() to create<br>
a new datatype named ftype. Here is the stdout for running it on 1 process.<br>
<br>
--- the stdout from both mpich and openmpi ----<br>
HEADER_EXTENT = 16 VAR_BEGIN = 32<br>
bodytype lb= 0 ub=20 extent=20 size=20<br>
ftype lb=32 ub=52 extent=20 size=36 true_lb= 0 true_extent=52<br>
<br>
[ 0]: 0 1 2 3 8 9 10 11 12 5<br>
[10]: 6 7 8 13 14 15 16 17 10 11<br>
[20]: 12 13 18 19 20 21 22<br>
<br>
Problems:<br>
1. ftype's lower bound should be 0. (mpich shows 32)<br>
2. ftype's extent should be 52. (mpich shows 20)<br>
3. packing 3 of ftypes to a contiguous array (27 integers) and its contents are incorrect.<br>
ps. explicitly resizing ftype with lb=0 and extent=52 produces correct packed results, though.<br>
<br>
Wei-keng<br>
<br>
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