Fix for the reduction of grid arrays which don't have any point on a specific

processor.


git-svn-id: http://svn.cactuscode.org/arrangements/CactusPUGH/PUGHReduce/trunk@42 d60812e6-3970-4df4-986e-c251b06effeb

1 files changed, 12 insertions, 2 deletions

diff --git a/src/ReductionNorm3.c b/src/ReductionNorm3.c
index 2ccb67b..f5036af 100644
--- a/src/ReductionNorm3.c
+++ b/src/ReductionNorm3.c
@@ -29,6 +29,7 @@ static int ReductionNorm3 (const cGH *GH,
                            int iterator[/* dim */],
                            const int points_per_dim[/* dim */],
                            int num_points,
+                           int have_local_points,
                            int num_inarrays,
                            const int intypes[/* num_inarrays */],
                            const void *const inarrays[/* num_inarrays */],
@@ -210,6 +211,7 @@ static int ReductionNorm3 (const cGH *GH,
                            int iterator[/* dim */],
                            const int points_per_dim[/* dim */],
                            int num_points,
+                           int have_local_points,
                            int num_inarrays,
                            const int intypes[/* num_inarrays */],
                            const void *const inarrays[/* num_inarrays */],
@@ -345,8 +347,16 @@ static int ReductionNorm3 (const cGH *GH,
   {
     local_outvals = malloc (total_outvals * sizeof (CCTK_REAL));
 
-    /* outvals[] contains now the local sum */
-    memcpy (local_outvals, outvals, total_outvals * sizeof (CCTK_REAL));
+    if (have_local_points)
+    {
+      /* outvals[] contains now the local sum */
+      memcpy (local_outvals, outvals, total_outvals * sizeof (CCTK_REAL));
+    }
+    else
+    {
+      /* initialize local values to zero */
+      memset (local_outvals, 0, total_outvals * sizeof (CCTK_REAL));
+    }
     if (proc < 0)
     {
       CACTUS_MPI_ERROR (MPI_Allreduce (local_outvals, outvals, total_outvals,