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| author | Mattias Andrée <maandree@kth.se> | 2016-03-16 14:30:29 +0100 |
|---|---|---|
| committer | Mattias Andrée <maandree@kth.se> | 2016-03-16 14:30:29 +0100 |
| commit | 3e3b44d087ab616089402129b2bc4c4831c6b33a (patch) | |
| tree | 2c0a6e9550dded9e336906514c6ad7343dc8257d /src/zpowu.c | |
| parent | Fix bug in libzahl_msb_nz_* and optimise and simplify libzahl_realloc (diff) | |
| download | libzahl-3e3b44d087ab616089402129b2bc4c4831c6b33a.tar.gz libzahl-3e3b44d087ab616089402129b2bc4c4831c6b33a.tar.bz2 libzahl-3e3b44d087ab616089402129b2bc4c4831c6b33a.tar.xz | |
Optimise zsqr, zmul, zstr, zdivmod, zpow, and zpowu
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat (limited to 'src/zpowu.c')
| -rw-r--r-- | src/zpowu.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/src/zpowu.c b/src/zpowu.c index c4a2a64..cf879e0 100644 --- a/src/zpowu.c +++ b/src/zpowu.c @@ -4,9 +4,14 @@ #define tb libzahl_tmp_pow_b +extern void zmul_impl(z_t a, z_t b, z_t c); +extern void zsqr_impl(z_t a, z_t b); + void zpowu(z_t a, z_t b, unsigned long long int c) { + int neg; + if (unlikely(!c)) { if (zzero(b)) libzahl_failure(-ZERROR_0_POW_0); @@ -17,12 +22,16 @@ zpowu(z_t a, z_t b, unsigned long long int c) return; } - zset(tb, b); + neg = znegative(b) && (c & 1); + zabs(tb, b); zsetu(a, 1); for (; c; c >>= 1) { if (c & 1) - zmul(a, a, tb); - zsqr(tb, tb); + zmul_impl(a, a, tb); + zsqr_impl(tb, tb); } + + if (neg) + zneg(a, a); } |