cuda: throughput2intensity function to show default

cuda.cpp

@@ -172,6 +172,21 @@ uint32_t cuda_default_throughput(int thr_id, uint32_t defcount)
 	return throughput;
 }
 
+// since 1.8.3
+double throughput2intensity(uint32_t throughput)
+{
+	double intensity = 0.;
+	uint32_t ws = throughput;
+	uint8_t i = 0;
+	while (ws > 1 && i++ < 32)
+		ws = ws >> 1;
+	intensity = (double) i;
+	if (i && ((1U << i) < throughput)) {
+		intensity += ((double) (throughput-(1U << i)) / (1U << i));
+	}
+	return intensity;
+}
+
 // if we use 2 threads on the same gpu, we need to reinit the threads
 void cuda_reset_device(int thr_id, bool *init)
 {

lbry/lbry.cu

@@ -116,6 +116,7 @@ extern "C" int scanhash_lbry(int thr_id, struct work *work, uint32_t max_nonce,
 			cudaDeviceSetCacheConfig(cudaFuncCachePreferL1);
 			CUDA_LOG_ERROR();
 		}
+		gpulog(LOG_INFO, thr_id, "Intensity set to %g, %u cuda threads", throughput2intensity(throughput), throughput);
 
 		if(device_sm[dev_id] <= 500)
 			CUDA_SAFE_CALL(cudaMalloc(&d_hash[thr_id], (size_t) 8 * sizeof(uint64_t) * throughput));

miner.h

@@ -513,6 +513,7 @@ int cuda_available_memory(int thr_id);
 
 uint32_t cuda_default_throughput(int thr_id, uint32_t defcount);
 #define device_intensity(t,f,d) cuda_default_throughput(t,d)
+double throughput2intensity(uint32_t throughput);
 
 void cuda_log_lasterror(int thr_id, const char* func, int line);
 void cuda_clear_lasterror();