static void
test_ctz_clz(void)
{
header();
for (size_t i = 0; i < sizeof(vals) / sizeof(vals[0]); i++) {
if (vals[i] == 0)
continue;
uint64_t val64 = vals[i];
uint32_t val32 = (uint32_t) vals[i];
printf("bit_ctz_u64(%" PRIu64 ") => %d\n", val64,
bit_ctz_u64(val64));
printf("bit_clz_u64(%" PRIu64 ") => %d\n", val64,
bit_clz_u64(val64));
if (vals[i] > UINT32_MAX)
continue;
printf("bit_ctz_u32(%" PRIu32 ") => %d\n", val32,
bit_ctz_u32(val32));
printf("bit_clz_u32(%" PRIu32 ") => %d\n", val32,
bit_clz_u32(val32));
}
footer();
}
int *
bit_index_u32(uint32_t x, int *indexes, int offset)
{
#if defined(HAVE_BUILTIN_CTZ)
int prev_pos = 0;
int i = 0;
#if defined(HAVE_BUILTIN_POPCOUNT)
/* fast implementation using built-in popcount function */
const int count = bit_count_u32(x);
while (i < count) {
#else
/* sligtly slower implementation without using built-in popcount */
while(x) {
#endif
/* use ctz */
const int a = bit_ctz_u32(x);
prev_pos += a + 1;
x >>= a;
x >>= 1;
indexes[i++] = offset + prev_pos;
}
indexes[i] = 0;
return indexes + i;
#else /* !defined(HAVE_BUILTIN_CTZ) */
BITINDEX_NAIVE(uint32_t, x, sizeof(uint32_t) * CHAR_BIT);
#endif
}
int *
bit_index_u64(uint64_t x, int *indexes, int offset) {
#if defined(HAVE_CTZLL)
int prev_pos = 0;
int i = 0;
#if defined(HAVE_POPCOUNTLL)
/* fast implementation using built-in popcount function */
const int count = bit_count_u64(x);
while (i < count) {
#else
/* sligtly slower implementation without using built-in popcount */
while(x) {
#endif
/* use ctz */
const int a = bit_ctz_u64(x);
prev_pos += a + 1;
x >>= a;
x >>= 1;
indexes[i++] = offset + prev_pos;
}
indexes[i] = 0;
return indexes + i;
#else /* !defined(HAVE_CTZ) */
BITINDEX_NAIVE(uint64_t, x, sizeof(uint64_t) * CHAR_BIT);
#endif
}
#undef BITINDEX_NAIVE
extern inline void
bit_iterator_init(struct bit_iterator *it, const void *data, size_t size,
bool set);
extern inline size_t
bit_iterator_next(struct bit_iterator *it);
