Migrate model class to Tensor

include/backend/cuda.cuh

@@ -1,8 +1,29 @@
 #pragma once
 
+#include <cstdio>
+
 #include "backend.hpp"
 #include "tensor.hpp"
 
+#ifndef BLOCK_SIZE
+#define BLOCK_SIZE 128
+#endif // BLOCK_SIZE
+
+/**
+ * @brief CUDA error checking macro
+ * 
+ */
+#define CUDA_CHECK(call) \
+do { \
+    cudaError_t result = call; \
+    if (result != cudaSuccess) { \
+        fprintf(stderr, "CUDA error at %s:%d code=%d(%s) \"%s\" \n", \
+                __FILE__, __LINE__, static_cast<unsigned int>(result), \
+                cudaGetErrorString(result), #call); \
+        exit(EXIT_FAILURE); \
+    } \
+} while (0)
+
 namespace CUDANet::Backend {
 
 class CUDA : public Backend {