diff options
-rw-r--r-- | numeric.c | 36 |
1 files changed, 35 insertions, 1 deletions
@@ -2177,6 +2177,40 @@ fix_divmod(x, y) return rb_num_coerce_bin(x, y); } +static VALUE +int_pow(x, y) + long x; + unsigned long y; +{ + int neg = x < 0; + long z = 1; + + if (neg) x = -x; + if (y & 1) z = x; + y &= ~1; + do { + while (y % 2 == 0) { + long x2 = x * x; + if (x2 < x || !POSFIXABLE(x2)) { + bignum: + return rb_big_mul(rb_big_pow(rb_int2big(x), LONG2NUM(y)), + rb_int2big(neg ? -z : z)); + } + x = x2; + y >>= 1; + } + { + long xz = x * z; + if (xz < z || xz < x || !POSFIXABLE(xz)) { + goto bignum; + } + z = xz; + } + } while (--y); + if (neg) z = -z; + return LONG2NUM(z); +} + /* * call-seq: * fix ** other => Numeric @@ -2201,7 +2235,7 @@ fix_pow(x, y) if (b == 1) return x; a = FIX2LONG(x); if (b > 0) { - return rb_big_pow(rb_int2big(a), y); + return int_pow(a, b); } return rb_float_new(pow((double)a, (double)b)); } else if (TYPE(y) == T_FLOAT) { |