First cut of handling MPI_IN_PLACE:

- added relevant logic for everything except
  mca_coll_basic_reduce_log_intra() -- need some help from George /
  Edgar on this one...
- replaced ompi_ddt_sndrcv() with ompi_ddt_copy_content_same_ddt()
  where relevant
- removed some "if (size > 1)" conditionals, because the self coll
  module will always be chosen for collectives where size==1

Waiting for BA's tests to check the validity of this IN_PLACE stuff.
We'll see how it goes!

This commit was SVN r7351.

ompi/mca/coll/basic/coll_basic_allgather.c

@@ -39,23 +39,54 @@ mca_coll_basic_allgather_intra(void *sbuf, int scount,
                                int rcount, struct ompi_datatype_t *rdtype,
                                struct ompi_communicator_t *comm)
 {
-    int size;
     int err;
+    char *inplace_temp = NULL;
+    long true_lb, true_extent, lb, extent;
+
+    /* Handle MPI_IN_PLACE (see explanantion in reduce.c for how to
+       allocate temp buffer) */
+
+    if (MPI_IN_PLACE == sbuf) {
+        sbuf = rbuf;
+        sdtype = rdtype;
+        scount = rcount;
+
+        ompi_ddt_get_extent(rdtype, &lb, &extent);
+        ompi_ddt_get_true_extent(rdtype, &true_lb, &true_extent);
+        inplace_temp = malloc(true_extent + (rcount - 1) * extent);
+        if (NULL == inplace_temp) {
+            return OMPI_ERR_OUT_OF_RESOURCE;
+        }
+        rbuf = inplace_temp - lb;
+    }
 
     /* Gather and broadcast. */
 
-    size = ompi_comm_size(comm);
-
     err = comm->c_coll.coll_gather(sbuf, scount, sdtype, rbuf, rcount,
                                    rdtype, 0, comm);
     if (MPI_SUCCESS != err) {
         return err;
     }
 
-    err = comm->c_coll.coll_bcast(rbuf, rcount * size, rdtype, 0, comm);
+    err = comm->c_coll.coll_bcast(rbuf, rcount * ompi_comm_size(comm), 
+                                  rdtype, 0, comm);
+    if (MPI_SUCCESS != err) {
         return err;
     }
 
+    /* If we're IN_PLACE, copy back out (sendcount and sendtype are
+       ignored) */
+
+    if (NULL != inplace_temp) {
+        ompi_ddt_copy_content_same_ddt(rdtype, rcount, rbuf, sbuf);
+        free(inplace_temp);
+    }
+
+    /* All done */
+
+    return MPI_SUCCESS;
+}
+
 
 /*
  *	allgather_inter

ompi/mca/coll/basic/coll_basic_allgatherv.c

@@ -38,15 +38,22 @@ mca_coll_basic_allgatherv_intra(void *sbuf, int scount,
                                 struct ompi_datatype_t *rdtype,
                                 struct ompi_communicator_t *comm)
 {
-    int i, size;
+    int i, size, rank;
     int err;
 
     /* Collect all values at each process, one at a time. */
 
     size = ompi_comm_size(comm);
+    rank = ompi_comm_rank(comm);
     for (i = 0; i < size; ++i) {
+        if (MPI_IN_PLACE == sbuf) {
+            err = comm->c_coll.coll_gatherv(MPI_IN_PLACE, 0, 
+                                            MPI_DATATYPE_NULL, rbuf,
+                                            rcounts, disps, rdtype, i, comm);
+        } else {
             err = comm->c_coll.coll_gatherv(sbuf, scount, sdtype, rbuf,
                                             rcounts, disps, rdtype, i, comm);
+        }
         if (MPI_SUCCESS != err) {
             return err;
         }

ompi/mca/coll/basic/coll_basic_exscan.c

@@ -101,9 +101,8 @@ mca_coll_basic_exscan_intra(void *sbuf, void *rbuf, int count,
         /* If we're commutative, we can copy my sbuf into the reduction
          * buffer before the receive completes */
 
-        err =
-            ompi_ddt_sndrcv(sbuf, count, dtype, reduce_buffer, count,
-                            dtype);
+        err = ompi_ddt_copy_content_same_ddt(dtype, count, 
+                                             reduce_buffer, sbuf);
         if (MPI_SUCCESS != err) {
             goto error;
         }
@@ -133,9 +132,8 @@ mca_coll_basic_exscan_intra(void *sbuf, void *rbuf, int count,
             goto error;
         }
 
-        err =
-            ompi_ddt_sndrcv(rbuf, count, dtype, reduce_buffer, count,
-                            dtype);
+        err = ompi_ddt_copy_content_same_ddt(dtype, count, 
+                                             reduce_buffer, rbuf);
         if (MPI_SUCCESS != err) {
             goto error;
         }

ompi/mca/coll/basic/coll_basic_reduce.c

@@ -45,6 +45,7 @@ mca_coll_basic_reduce_lin_intra(void *sbuf, void *rbuf, int count,
     long true_lb, true_extent, lb, extent;
     char *free_buffer = NULL;
     char *pml_buffer = NULL;
+    char *inplace_temp = NULL;
     char *inbuf;
 
     /* Initialize */
@@ -186,10 +187,19 @@ mca_coll_basic_reduce_lin_intra(void *sbuf, void *rbuf, int count,
      * 
      */
 
-    if (size > 1) {
     ompi_ddt_get_extent(dtype, &lb, &extent);
     ompi_ddt_get_true_extent(dtype, &true_lb, &true_extent);
 
+    if (MPI_IN_PLACE == sbuf) {
+        sbuf = rbuf;
+        inplace_temp = malloc(true_extent + (count - 1) * extent);
+        if (NULL == inplace_temp) {
+            return OMPI_ERR_OUT_OF_RESOURCE;
+        }
+        rbuf = inplace_temp - lb;
+    }
+
+    if (size > 1) {
         free_buffer = malloc(true_extent + (count - 1) * extent);
         if (NULL == free_buffer) {
             return OMPI_ERR_OUT_OF_RESOURCE;
@@ -200,7 +210,7 @@ mca_coll_basic_reduce_lin_intra(void *sbuf, void *rbuf, int count,
     /* Initialize the receive buffer. */
 
     if (rank == (size - 1)) {
-        err = ompi_ddt_sndrcv(sbuf, count, dtype, rbuf, count, dtype);
+        err = ompi_ddt_copy_content_same_ddt(dtype, count, rbuf, sbuf);
     } else {
         err = MCA_PML_CALL(recv(rbuf, count, dtype, size - 1,
                                 MCA_COLL_BASE_TAG_REDUCE, comm,
@@ -237,6 +247,10 @@ mca_coll_basic_reduce_lin_intra(void *sbuf, void *rbuf, int count,
         ompi_op_reduce(op, inbuf, rbuf, count, dtype);
     }
 
+    if (NULL != inplace_temp) {
+        err = ompi_ddt_copy_content_same_ddt(dtype, count, sbuf, inplace_temp);
+        free(inplace_temp);
+    }
     if (NULL != free_buffer) {
         free(free_buffer);
     }
@@ -274,6 +288,7 @@ mca_coll_basic_reduce_log_intra(void *sbuf, void *rbuf, int count,
     char *pml_buffer = NULL;
     char *snd_buffer = sbuf;
     char *rcv_buffer = rbuf;
+    char *inplace_temp = NULL;
 
     /* JMS Codearound for now -- if the operations is not communative,
      * just call the linear algorithm.  Need to talk to Edgar / George
@@ -294,7 +309,6 @@ mca_coll_basic_reduce_log_intra(void *sbuf, void *rbuf, int count,
     /* Allocate the incoming and resulting message buffers.  See lengthy
      * rationale above. */
 
-    if (size > 1) {
     ompi_ddt_get_extent(dtype, &lb, &extent);
     ompi_ddt_get_true_extent(dtype, &true_lb, &true_extent);
     
@@ -321,7 +335,6 @@ mca_coll_basic_reduce_log_intra(void *sbuf, void *rbuf, int count,
         }
         rbuf = free_rbuf - lb;
     }
-    }
 
     /* Loop over cube dimensions. High processes send to low ones in the
      * dimension. */
@@ -397,8 +410,8 @@ mca_coll_basic_reduce_log_intra(void *sbuf, void *rbuf, int count,
                  * buffer into a temp buffer (pml_buffer) and then reduce
                  * what we just received against it. */
                 if (!ompi_op_is_commute(op)) {
-                    ompi_ddt_sndrcv(sbuf, count, dtype, pml_buffer, count,
-                                    dtype);
+                    ompi_ddt_copy_content_same_ddt(dtype, count, pml_buffer,
+                                                   sbuf);
                     ompi_op_reduce(op, rbuf, pml_buffer, count, dtype);
                 } else {
                     ompi_op_reduce(op, sbuf, pml_buffer, count, dtype);
@@ -416,7 +429,7 @@ mca_coll_basic_reduce_log_intra(void *sbuf, void *rbuf, int count,
     err = MPI_SUCCESS;
     if (0 == vrank) {
         if (root == rank) {
-            ompi_ddt_sndrcv(snd_buffer, count, dtype, rbuf, count, dtype);
+            ompi_ddt_copy_content_same_ddt(dtype, count, rbuf, snd_buffer);
         } else {
             err = MCA_PML_CALL(send(snd_buffer, count,
                                     dtype, root, MCA_COLL_BASE_TAG_REDUCE,

ompi/mca/coll/basic/coll_basic_scan.c

@@ -55,10 +55,14 @@ mca_coll_basic_scan_intra(void *sbuf, void *rbuf, int count,
     /* If I'm rank 0, just copy into the receive buffer */
 
     if (0 == rank) {
-        err = ompi_ddt_sndrcv(sbuf, count, dtype, rbuf, count, dtype);
+        if (MPI_IN_PLACE != sbuf) {
+            err = ompi_ddt_copy_content_same_ddt(dtype, count, rbuf, sbuf);
             if (MPI_SUCCESS != err) {
                 return err;
             }
+        } else {
+            return MPI_SUCCESS;
+        }
     }
 
     /* Otherwise receive previous buffer and reduce. */
@@ -68,7 +72,6 @@ mca_coll_basic_scan_intra(void *sbuf, void *rbuf, int count,
          * listed in coll_basic_reduce.c.  Use this temporary buffer to
          * receive into, later. */
 
-        if (size > 1) {
         ompi_ddt_get_extent(dtype, &lb, &extent);
         ompi_ddt_get_true_extent(dtype, &true_lb, &true_extent);
 
@@ -77,17 +80,18 @@ mca_coll_basic_scan_intra(void *sbuf, void *rbuf, int count,
             return OMPI_ERR_OUT_OF_RESOURCE;
         }
         pml_buffer = free_buffer - lb;
-        }
 
         /* Copy the send buffer into the receive buffer. */
 
-        err = ompi_ddt_sndrcv(sbuf, count, dtype, rbuf, count, dtype);
+        if (MPI_IN_PLACE != sbuf) {
+            err = ompi_ddt_copy_content_same_ddt(dtype, count, rbuf, sbuf);
             if (MPI_SUCCESS != err) {
                 if (NULL != free_buffer) {
                     free(free_buffer);
                 }
                 return err;
             }
+        }
 
         /* Receive the prior answer */