-#define PSXGPU_LCF (1<<31)
-#define PSXGPU_nBUSY (1<<26)
-#define PSXGPU_ILACE (1<<22)
-#define PSXGPU_DHEIGHT (1<<19)
+#ifndef __GPU_H__
+#define __GPU_H__
+
+#define PSXGPU_LCF (1u<<31)
+#define PSXGPU_nBUSY (1u<<26)
+#define PSXGPU_ILACE (1u<<22)
+#define PSXGPU_DHEIGHT (1u<<19)
+#define PSXGPU_FIELD (1u<<13)