Can set n{threads/blocks} using a macro.

You can now use the NTHREADS or NBLOCKS macros to set the number of CUDA threads/blocks. This is useful in a 'Makefile.local' file.

parrhoasm.cu

@@ -322,8 +322,14 @@ __global__ void cudaMulmod(GlobalThreadState *global_ts,
     // cuPrintf("d_b = %08X%08X\n", global_b_base[1], global_b_base[0]);
 }
 
+#if defined(NTHREADS) || defined(NBLOCKS)
+// must define both together
+int nthreads = NTHREADS;
+int nblocks = NBLOCKS;
+#else
 int nthreads = 25600;
 int nblocks = 50;
+#endif
 
 void cuda_dl(const ZZ_p &base, const ZZ_p &target, const ZZ &order,
 		const ZZ &modulus, unsigned int dpfreq, void *cbdata,
@@ -463,6 +469,11 @@ void cuda_dl(const ZZ_p &base, const ZZ_p &target, const ZZ &order,
     int local_launchcount = 0;
     bool stop_computing = false;
     unsigned int num_dps = 0;
+
+#ifdef VERBOSE
+    AtomicWriter(cerr) << getpid() << " Using (nblocks, nthreads): " << nblocks << ", " << nthreads << "\n";
+#endif
+
 #ifdef CHECK_RESULTS
     for (int ln=0; ln<nlaunch && stop_computing == false; ++ln)
 #else