diff options
Diffstat (limited to 'bignum.c')
| -rw-r--r-- | bignum.c | 37 |
1 files changed, 37 insertions, 0 deletions
@@ -1489,6 +1489,17 @@ bary_mul_normal(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, siz } } +VALUE +rb_big_mul_normal(VALUE x, VALUE y) +{ + size_t xn = RBIGNUM_LEN(x), yn = RBIGNUM_LEN(y), zn = xn + yn; + VALUE z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); + bary_mul_normal(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn); + RB_GC_GUARD(x); + RB_GC_GUARD(y); + return z; +} + /* efficient squaring (2 times faster than normal multiplication) * ref: Handbook of Applied Cryptography, Algorithm 14.16 * http://www.cacr.math.uwaterloo.ca/hac/about/chap14.pdf @@ -1558,6 +1569,19 @@ bary_mul_balance(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, si ALLOCV_END(work); } +VALUE +rb_big_mul_balance(VALUE x, VALUE y) +{ + size_t xn = RBIGNUM_LEN(x), yn = RBIGNUM_LEN(y), zn = xn + yn; + VALUE z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); + if (!(2 * xn <= yn || 3 * xn <= 2*(yn+2))) + rb_raise(rb_eArgError, "invalid bignum length"); + bary_mul_balance(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn); + RB_GC_GUARD(x); + RB_GC_GUARD(y); + return z; +} + /* multiplication by karatsuba method */ static void bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) @@ -1720,6 +1744,19 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, ALLOCV_END(work); } +VALUE +rb_big_mul_karatsuba(VALUE x, VALUE y) +{ + size_t xn = RBIGNUM_LEN(x), yn = RBIGNUM_LEN(y), zn = xn + yn; + VALUE z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); + if (!(xn <= yn && yn < 2 * xn)) + rb_raise(rb_eArgError, "invalid bignum length"); + bary_mul_karatsuba(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn); + RB_GC_GUARD(x); + RB_GC_GUARD(y); + return z; +} + static void bary_mul1(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) { |