diff --git a/ompi/op/op.c b/ompi/op/op.c
index bd7365e397..a18192f4e8 100644
--- a/ompi/op/op.c
+++ b/ompi/op/op.c
@@ -272,11 +272,17 @@ OBJ_CLASS_INSTANCE(ompi_op_t, opal_object_t,
  * MPI_OP_NULL
  * All types
  */
+#define FLAGS_NO_FLOAT \
+    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE)
+#define FLAGS \
+    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | \
+     OMPI_OP_FLAGS_FLOAT_ASSOC | OMPI_OP_FLAGS_COMMUTE)
+
 ompi_op_t ompi_mpi_op_null = {
     { NULL, 0 },
 
     "MPI_OP_NULL",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER_NULL,
       FORTRAN_INTEGER_NULL,
       FLOATING_POINT_NULL,
@@ -295,7 +301,7 @@ ompi_op_t ompi_mpi_op_max = {
     { NULL, 0 },
 
     "MPI_OP_MAX",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(max),
       FORTRAN_INTEGER(max),
       FLOATING_POINT(max),
@@ -313,7 +319,7 @@ ompi_op_t ompi_mpi_op_min = {
     { NULL, 0 },
 
     "MPI_OP_MIN",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(min),
       FORTRAN_INTEGER(min),
       FLOATING_POINT(min),
@@ -331,7 +337,7 @@ ompi_op_t ompi_mpi_op_sum = {
     { NULL, 0 },
 
     "MPI_OP_SUM",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS_NO_FLOAT,
     { C_INTEGER(sum),
       FORTRAN_INTEGER(sum),
       FLOATING_POINT(sum),
@@ -349,7 +355,7 @@ ompi_op_t ompi_mpi_op_prod = {
     { NULL, 0 },
 
     "MPI_OP_PROD",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS_NO_FLOAT,
     { C_INTEGER(prod),
       FORTRAN_INTEGER(prod),
       FLOATING_POINT(prod),
@@ -367,7 +373,7 @@ ompi_op_t ompi_mpi_op_land = {
     { NULL, 0 },
 
     "MPI_OP_LAND",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(land),
       FORTRAN_INTEGER_NULL,
       FLOATING_POINT_NULL,
@@ -385,7 +391,7 @@ ompi_op_t ompi_mpi_op_band = {
     { NULL, 0 },
 
     "MPI_OP_BAND",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(band),
       FORTRAN_INTEGER(band),
       FLOATING_POINT_NULL,
@@ -403,7 +409,7 @@ ompi_op_t ompi_mpi_op_lor = {
     { NULL, 0 },
 
     "MPI_OP_LOR",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(lor),
       FORTRAN_INTEGER_NULL,
       FLOATING_POINT_NULL,
@@ -421,7 +427,7 @@ ompi_op_t ompi_mpi_op_bor = {
     { NULL, 0 },
 
     "MPI_OP_BOR",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(bor),
       FORTRAN_INTEGER(bor),
       FLOATING_POINT_NULL,
@@ -439,7 +445,7 @@ ompi_op_t ompi_mpi_op_lxor = {
     { NULL, 0 },
 
     "MPI_OP_LXOR",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(lxor),
       FORTRAN_INTEGER_NULL,
       FLOATING_POINT_NULL,
@@ -457,7 +463,7 @@ ompi_op_t ompi_mpi_op_bxor = {
     { NULL, 0 },
 
     "MPI_OP_BXOR",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(bxor),
       FORTRAN_INTEGER(bxor),
       FLOATING_POINT_NULL,
@@ -493,7 +499,7 @@ ompi_op_t ompi_mpi_op_minloc = {
     { NULL, 0 },
 
     "MPI_OP_MINLOC",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER_NULL,
       FORTRAN_INTEGER_NULL,
       FLOATING_POINT_NULL,
@@ -510,7 +516,7 @@ ompi_op_t ompi_mpi_op_replace = {
     { NULL, 0 },
 
     "MPI_OP_REPLACE",
-    (OMPI_OP_FLAGS_INTRINSIC | OMPI_OP_FLAGS_ASSOC | OMPI_OP_FLAGS_COMMUTE),
+    FLAGS,
     { C_INTEGER(replace),
       FORTRAN_INTEGER(replace),
       FLOATING_POINT(replace),
diff --git a/ompi/op/op.h b/ompi/op/op.h
index 9f12acff0a..ea0c061d49 100644
--- a/ompi/op/op.h
+++ b/ompi/op/op.h
@@ -181,14 +181,22 @@ typedef void (ompi_op_fortran_handler_fn_t)(void *, void *,
 /*
  * Flags for MPI_Op
  */
+/** Set if the MPI_Op is a built-in operation */
 #define OMPI_OP_FLAGS_INTRINSIC    0x0001
-  /**< Set if the MPI_Op is a built-in operation */
+/** Set if the callback function is in Fortran */
 #define OMPI_OP_FLAGS_FORTRAN_FUNC 0x0002
-  /**< Set if the callback function is in Fortran */
+/** Set if the callback function is associative (MAX and SUM will both
+    have ASSOC set -- in fact, it will only *not* be set if we
+    implement some extensions to MPI, because MPI says that all
+    MPI_Op's should be associative, so this flag is really here for
+    future expansion) */
 #define OMPI_OP_FLAGS_ASSOC        0x0004
-  /**< Set if the callback function is associative */
-#define OMPI_OP_FLAGS_COMMUTE      0x0008
-  /**< Set if the callback function is communative */
+/** Set if the callback function is associative for floating point
+    operands (e.g., MPI_SUM will have ASSOC set, but will *not* have
+    FLOAT_ASSOC set)  */
+#define OMPI_OP_FLAGS_FLOAT_ASSOC  0x0008
+/** Set if the callback function is communative */
+#define OMPI_OP_FLAGS_COMMUTE      0x0010
 
 
 /**
@@ -424,6 +432,23 @@ static inline bool ompi_op_is_commute(ompi_op_t *op)
   return (bool) (0 != (op->o_flags & OMPI_OP_FLAGS_COMMUTE));
 }
 
+/**
+ * Check to see if an op is floating point associative or not
+ *
+ * @param op The op to check
+ *
+ * @returns true If the op is floating point associative
+ * @returns false If the op is not floating point associative
+ *
+ * Self-explanitory.  This is needed in a few top-level MPI functions;
+ * this function is provided to hide the internal structure field
+ * names.
+ */
+static inline bool ompi_op_is_float_assoc(ompi_op_t *op)
+{
+  return (bool) (0 != (op->o_flags & OMPI_OP_FLAGS_FLOAT_ASSOC));
+}
+
 
 /**
  * Perform a reduction operation.