From 386a02d2ae4d73bb7e620ff4b0d56c5b0e469c65 Mon Sep 17 00:00:00 2001
From: George Bosilca <bosilca@icl.utk.edu>
Date: Sun, 11 Jun 2006 19:57:49 +0000
Subject: [PATCH] Rewrite the subarray strictly following the MPI standard. Set
 the lb and ub as it should be. I hope I get it right this time ...

This commit was SVN r10293.
---
 ompi/mpi/c/type_create_subarray.c | 51 ++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 21 deletions(-)

diff --git a/ompi/mpi/c/type_create_subarray.c b/ompi/mpi/c/type_create_subarray.c
index 47733ceab4..96cd939088 100644
--- a/ompi/mpi/c/type_create_subarray.c
+++ b/ompi/mpi/c/type_create_subarray.c
@@ -42,8 +42,8 @@ int MPI_Type_create_subarray(int ndims,
 
 {
     MPI_Datatype last_type; 
-    int32_t i, step, end_loop;
-    int32_t block_length[2], start[2];
+    int32_t i, step, start_loop, end_loop;
+    MPI_Aint size, displ, extent;
 
     if (MPI_PARAM_CHECK) {
         OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
@@ -67,41 +67,50 @@ int MPI_Type_create_subarray(int ndims,
         }
     }
     /* If the ndims is zero then return the NULL datatype */
-    if( ndims < 1 ) {
-        *newtype = &ompi_mpi_datatype_null;
+    if( ndims < 2 ) {
+        if( 0 == ndims ) {
+            *newtype = &ompi_mpi_datatype_null;
+            return MPI_SUCCESS;
+        }
+        ompi_ddt_create_contiguous( subsize_array[0], oldtype, newtype );
         return MPI_SUCCESS;
     }
 
     if( MPI_ORDER_C == order ) {
-        i = ndims - 1;
+        start_loop = i = ndims - 1;
         step = -1;
         end_loop = -1;
     } else {
-        i = 0;
+        start_loop = i = 0;
         step = 1;
         end_loop = ndims - 1;
     }
 
+    ompi_ddt_type_extent( oldtype, &extent );
+
     /* As we know that the ndims is at least 1 we can start by creating the first dimension data
      * outside the loop, such that we dont have to create a duplicate of the oldtype just to be able
      * to free it.
      */
-    block_length[0] = subsize_array[i];
-    block_length[1] = 0;
-    start[0] = start_array[i];
-    start[1] = size_array[i];
-    ompi_ddt_create_indexed( 2, block_length, start, oldtype, newtype );
-    last_type = *newtype;
-    for( i += step; i != end_loop; i += step ) {
-        block_length[0] = subsize_array[i];
-        block_length[1] = 0;
-        start[0] = start_array[i];
-        start[1] = size_array[i];
-        ompi_ddt_create_indexed( 2, block_length, start, last_type, newtype );
-        ompi_ddt_destroy( &last_type );
-        last_type = *newtype;
-    }
+    ompi_ddt_create_vector( subsize_array[i+step], subsize_array[i], size_array[i],
+                            oldtype, newtype );
 
+    last_type = *newtype;
+    size = size_array[i] * size_array[i+step];
+    displ = start_array[i] + start_array[i+step] * size_array[i];
+    for( i += 2 * step; i != end_loop; i += step ) {
+        last_type = *newtype;
+        ompi_ddt_create_vector( subsize_array[i], 1, size_array[i],
+                                last_type, newtype );
+        ompi_ddt_destroy( &last_type );
+        displ += size * start_array[i];
+        size *= size_array[i];
+    }
+    
+    ompi_ddt_create_resized( last_type, displ * extent,
+                             (size - start_array[start_loop]) * extent, newtype );
+    ompi_ddt_destroy( &last_type );
+    
     {
         int* a_i[5];