diff options
Diffstat (limited to 'bignum.c')
-rw-r--r-- | bignum.c | 12 |
1 files changed, 6 insertions, 6 deletions
@@ -2157,14 +2157,14 @@ bigmul1_karatsuba(VALUE x, VALUE y) t3 = bigmul0(xh, yh); i = xn + yn - n; - /* add t3 to middle bytes of the result (z1) */ - bigadd_core(zds + n, i, BDIGITS(t3), big_real_len(t3), zds + n, i); + /* subtract t1 from t3 */ + bigsub_core(BDIGITS(t3), big_real_len(t3), BDIGITS(t1), t1n, BDIGITS(t3), big_real_len(t3)); - /* subtract t1 from middle bytes of the result (z1) */ - bigsub_core(zds + n, i, BDIGITS(t1), t1n, zds + n, i); + /* subtract t2 from t3; t3 is now the middle term of the product */ + if (t2 != Qundef) bigsub_core(BDIGITS(t3), big_real_len(t3), BDIGITS(t2), t2n, BDIGITS(t3), big_real_len(t3)); - /* subtract t2 from middle bytes of the result (z1) */ - if (t2 != Qundef) bigsub_core(zds + n, i, BDIGITS(t2), t2n, zds + n, i); + /* add t3 to middle bytes of the result (z1) */ + bigadd_core(zds + n, i, BDIGITS(t3), big_real_len(t3), zds + n, i); return z; } |