#include <stdlib.h>	/* For strtoll().	*/

#include "libutils.h"

/* Count the number of 1 bits. */
static int pop(uint64_t x)
{
	int n = 0;
	while (x) {
		n++;
		x = x & (x - 1);
	}
	return n;
}

int ilog2(uint64_t x)
{
	x = x | (x >>  1);
	x = x | (x >>  2);
	x = x | (x >>  4);
	x = x | (x >>  8);
	x = x | (x >> 16);
	x = x | (x >> 32);
	return pop(x) - 1;
}

/* Least power of 2 greater than or equal to x. */
static uint64_t clp2(uint64_t x)
{
	x = x - 1;
	x = x | (x >>  1);
	x = x | (x >>  2);
	x = x | (x >>  4);
	x = x | (x >>  8);
	x = x | (x >> 16);
	x = x | (x >> 32);
	return x + 1;
}

int ceiling_log2(uint64_t x)
{
	return ilog2(clp2(x));
}

void *align_mem(void *p, int order)
{
	uintptr_t ip = (uintptr_t)p;
	uintptr_t head = align_head(order);
	return (void *)(   (ip + head) & ~head   );
}

long long arg_to_ll_bytes(const struct argp_state *state,
	const char *arg)
{
	char *end;
	long long ll = strtoll(arg, &end, 0);
	if (end == arg)
		argp_error(state, "An integer must be provided");

	/* Deal with units. */
	switch (*end) {
	case 's':
	case 'S': /* Sectors */
		ll <<= 9;
		end++;
		break;

	case 'k':
	case 'K': /* KB */
		ll <<= 10;
		end++;
		break;

	case 'm':
	case 'M': /* MB */
		ll <<= 20;
		end++;
		break;

	case 'g':
	case 'G': /* GB */
		ll <<= 30;
		end++;
		break;

	case 't':
	case 'T': /* TB */
		ll <<= 40;
		end++;
		break;
	}

	if (*end)
		argp_error(state, "`%s' is not an integer", arg);
	return ll;
}