rework structure

hifive1-vp/hello/bsp/include/sifive/bits.h

@@ -0,0 +1,35 @@
+#ifndef _RISCV_BITS_H
+#define _RISCV_BITS_H
+
+#define likely(x) __builtin_expect((x), 1)
+#define unlikely(x) __builtin_expect((x), 0)
+
+#define ROUNDUP(a, b) ((((a)-1)/(b)+1)*(b))
+#define ROUNDDOWN(a, b) ((a)/(b)*(b))
+
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define CLAMP(a, lo, hi) MIN(MAX(a, lo), hi)
+
+#define EXTRACT_FIELD(val, which) (((val) & (which)) / ((which) & ~((which)-1)))
+#define INSERT_FIELD(val, which, fieldval) (((val) & ~(which)) | ((fieldval) * ((which) & ~((which)-1))))
+
+#define STR(x) XSTR(x)
+#define XSTR(x) #x
+
+#ifdef __riscv64
+# define SLL32    sllw
+# define STORE    sd
+# define LOAD     ld
+# define LWU      lwu
+# define LOG_REGBYTES 3
+#else
+# define SLL32    sll
+# define STORE    sw
+# define LOAD     lw
+# define LWU      lw
+# define LOG_REGBYTES 2
+#endif
+#define REGBYTES (1 << LOG_REGBYTES)
+
+#endif