/*
* arm arch v7 routines other than cache-related ones.
*
* calling this arch-v7.c would confuse the mk scripts,
* to which a filename arch*.c is magic.
*/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"
#include "io.h"
#include "arm.h"

/*
* these routines should be cheap enough that there will
* be no hesitation to use them.
*
* once 5c in-lines vlong ops, just use the vlong versions.
*/

/* see Hacker's Delight if this isn't obvious */
#define ISPOW2(i) (((i) & ((i) - 1)) == 0)

int
ispow2(uvlong uvl)
{
       /* see Hacker's Delight if this isn't obvious */
       return ISPOW2(uvl);
}

static int
isulpow2(ulong ul)                              /* temporary speed hack */
{
       return ISPOW2(ul);
}

/*
* return exponent of smallest power of 2 ≥ n
*/
int
log2(ulong n)
{
       int i;

       i = BI2BY*BY2WD - 1 - clz(n);
       if (n == 0 || !ISPOW2(n))
               i++;
       return i;
}