fix build warnings with openMPI

Author: JuliaRS

src_c/IMB_output.c

@@ -343,9 +343,9 @@ Input variables:
 
             case SAMPLE_FAILED_INT_OVERFLOW:
 #ifdef MPI1
-                sprintf(aux_string + offset, " int-overflow; The production rank*size=%u caused int overflow for given sample; use flag \"-data_type double\"", size*(c_info->w_num_procs));
+                sprintf(aux_string + offset, " int-overflow; The production rank*size caused int overflow for given sample; use flag \"-data_type double\"");
 #else
-                sprintf(aux_string + offset, " int-overflow; The production rank*size=%u caused int overflow for given sample", size*(c_info->w_num_procs));
+                sprintf(aux_string + offset, " int-overflow; The production rank*size caused int overflow for given sample");
 #endif
                 break;
             case SAMPLE_FAILED_TIME_OUT:

src_cpp/Makefile

@@ -81,6 +81,12 @@ endif
 ifeq "$(CC)" "gcc"
 override CFLAGS += -fopenmp
 endif
+ifeq "$(CXX)" "mpicxx"
+override CXXFLAGS += -fopenmp
+endif
+ifeq "$(CC)" "mpicc"
+override CFLAGS += -fopenmp
+endif
 endif
 
 # ICC ICPC