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author | jan.nijtmans <nijtmans@users.sourceforge.net> | 2017-09-18 15:13:40 (GMT) |
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committer | jan.nijtmans <nijtmans@users.sourceforge.net> | 2017-09-18 15:13:40 (GMT) |
commit | db596f769f7d0d74193f88b121b949bce6853ebf (patch) | |
tree | feb67968040c4869b021497e6e8859e0e90e41be /libtommath/bn_mp_mul_2.c | |
parent | 36098aafd9bbd015808f0607f94acc590d192e0d (diff) | |
parent | 7a4fe54c26332c21cd95b01cc07bd74714d060ae (diff) | |
download | tcl-z_modifier.zip tcl-z_modifier.tar.gz tcl-z_modifier.tar.bz2 |
Merge trunkz_modifier
Diffstat (limited to 'libtommath/bn_mp_mul_2.c')
-rw-r--r-- | libtommath/bn_mp_mul_2.c | 100 |
1 files changed, 50 insertions, 50 deletions
diff --git a/libtommath/bn_mp_mul_2.c b/libtommath/bn_mp_mul_2.c index d22fd89..1744681 100644 --- a/libtommath/bn_mp_mul_2.c +++ b/libtommath/bn_mp_mul_2.c @@ -16,64 +16,64 @@ */ /* b = a*2 */ -int mp_mul_2(mp_int * a, mp_int * b) +int mp_mul_2(const mp_int *a, mp_int *b) { - int x, res, oldused; + int x, res, oldused; - /* grow to accomodate result */ - if (b->alloc < (a->used + 1)) { - if ((res = mp_grow (b, a->used + 1)) != MP_OKAY) { - return res; - } - } + /* grow to accomodate result */ + if (b->alloc < (a->used + 1)) { + if ((res = mp_grow(b, a->used + 1)) != MP_OKAY) { + return res; + } + } - oldused = b->used; - b->used = a->used; + oldused = b->used; + b->used = a->used; - { - mp_digit r, rr, *tmpa, *tmpb; + { + mp_digit r, rr, *tmpa, *tmpb; - /* alias for source */ - tmpa = a->dp; - - /* alias for dest */ - tmpb = b->dp; + /* alias for source */ + tmpa = a->dp; - /* carry */ - r = 0; - for (x = 0; x < a->used; x++) { - - /* get what will be the *next* carry bit from the - * MSB of the current digit - */ - rr = *tmpa >> ((mp_digit)(DIGIT_BIT - 1)); - - /* now shift up this digit, add in the carry [from the previous] */ - *tmpb++ = ((*tmpa++ << ((mp_digit)1)) | r) & MP_MASK; - - /* copy the carry that would be from the source - * digit into the next iteration - */ - r = rr; - } + /* alias for dest */ + tmpb = b->dp; + + /* carry */ + r = 0; + for (x = 0; x < a->used; x++) { + + /* get what will be the *next* carry bit from the + * MSB of the current digit + */ + rr = *tmpa >> ((mp_digit)(DIGIT_BIT - 1)); - /* new leading digit? */ - if (r != 0) { - /* add a MSB which is always 1 at this point */ - *tmpb = 1; - ++(b->used); - } + /* now shift up this digit, add in the carry [from the previous] */ + *tmpb++ = ((*tmpa++ << ((mp_digit)1)) | r) & MP_MASK; - /* now zero any excess digits on the destination - * that we didn't write to - */ - tmpb = b->dp + b->used; - for (x = b->used; x < oldused; x++) { - *tmpb++ = 0; - } - } - b->sign = a->sign; - return MP_OKAY; + /* copy the carry that would be from the source + * digit into the next iteration + */ + r = rr; + } + + /* new leading digit? */ + if (r != 0) { + /* add a MSB which is always 1 at this point */ + *tmpb = 1; + ++(b->used); + } + + /* now zero any excess digits on the destination + * that we didn't write to + */ + tmpb = b->dp + b->used; + for (x = b->used; x < oldused; x++) { + *tmpb++ = 0; + } + } + b->sign = a->sign; + return MP_OKAY; } #endif |