Enable GDA+IPC (#249)

* Enable GDA+IPC
Fix ROCSHMEM_DISABLE_IPC for both RO and GDA

* add more functionality to bootstrap class

we need a few more functions in the boostrap class to be able to fully
handle the rocshmem requirements:
 - add a function to return the list of local ranks
 - provide a groupAllgather operation which takes a vector of ranks
   participating
 - provide a groupAlltoall operation which takes a vector of ranks
   participating

Also, update the functionality of the gda-Alltoall and gda-Allreduce
operations to take advantage of these functions.

* ipc_policy adapted to use bootstrap groupallgather

* bugfix: there was a mistake in computing sendto in groupallgather

* bugfix: shm_size and shm_rank were set in a local variable rather than
the class member

* mpi-bootstrap: remove an unecessary allgather

---------

Co-authored-by: Edgar Gabriel <Edgar.Gabriel@amd.com>

src/rocshmem.cpp

@@ -35,15 +35,15 @@
 
 #include "backend_bc.hpp"
 #include "context_incl.hpp"
-#if defined(USE_RO)
+#if defined(USE_GDA)
+#include "gda/backend_gda.hpp"
+#include "gda/context_gda_tmpl_host.hpp"
+#elif defined(USE_RO)
 #include "reverse_offload/backend_ro.hpp"
 #include "reverse_offload/context_ro_tmpl_host.hpp"
 #elif defined(USE_IPC)
 #include "ipc/backend_ipc.hpp"
 #include "ipc/context_ipc_tmpl_host.hpp"
-#elif defined(USE_GDA)
-#include "gda/backend_gda.hpp"
-#include "gda/context_gda_tmpl_host.hpp"
 #else
 #error "Select one backend among USE_RO, USE_IPC, USE_GDA"
 #endif
@@ -94,15 +94,15 @@ rocshmem_ctx_t ROCSHMEM_HOST_CTX_DEFAULT;
 
   mpi_instance = new MPIInstance(comm);
 
-#if defined(USE_RO)
+#if defined(USE_GDA)
+  CHECK_HIP(hipHostMalloc(&backend, sizeof(GDABackend)));
+  backend = new (backend) GDABackend(comm);
+#elif defined(USE_RO)
   CHECK_HIP(hipHostMalloc(&backend, sizeof(ROBackend)));
   backend = new (backend) ROBackend(comm);
 #elif defined(USE_IPC)
   CHECK_HIP(hipHostMalloc(&backend, sizeof(IPCBackend)));
   backend = new (backend) IPCBackend(comm);
-#elif defined(USE_GDA)
-  CHECK_HIP(hipHostMalloc(&backend, sizeof(GDABackend)));
-  backend = new (backend) GDABackend(comm);
 #endif
 
   if (!backend) {
@@ -174,15 +174,15 @@ rocshmem_ctx_t ROCSHMEM_HOST_CTX_DEFAULT;
 
   rocm_init();
 
-#if defined(USE_RO)
+#if defined(USE_GDA)
+  CHECK_HIP(hipHostMalloc(&backend, sizeof(GDABackend)));
+  backend = new (backend) GDABackend(bootstrap);
+#elif defined(USE_RO)
   printf("RO Backend requires MPI library to be initialized, even when using uniqueId initializations!\n");
   abort();
 #elif defined(USE_IPC)
   CHECK_HIP(hipHostMalloc(&backend, sizeof(IPCBackend)));
   backend = new (backend) IPCBackend(bootstrap);
-#elif defined(USE_GDA)
-  CHECK_HIP(hipHostMalloc(&backend, sizeof(GDABackend)));
-  backend = new (backend) GDABackend(bootstrap);
 #endif
 
   if (!backend) {