diff options
Diffstat (limited to 'src/zpowu.c')
| -rw-r--r-- | src/zpowu.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/zpowu.c b/src/zpowu.c new file mode 100644 index 0000000..bc0c6dd --- /dev/null +++ b/src/zpowu.c @@ -0,0 +1,32 @@ +/* See LICENSE file for copyright and license details. */ +#include "internals" + +#include <errno.h> + +#define tb libzahl_tmp_pow_b + + +void +zpowu(z_t a, z_t b, unsigned long long int c) +{ + if (!c) { + if (zzero(b)) { + errno = EDOM; /* Indeterminate form: 0:th power of 0 */ + FAILURE_JUMP(); + } + zsetu(a, 1); + return; + } else if (zzero(b)) { + SET_SIGNUM(a, 0); + return; + } + + zset(tb, b); + zsetu(a, 1); + + for (; c; c >>= 1) { + if (c & 1) + zmul(a, a, tb); + zsqr(tb, tb); + } +} |
