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rational.c: optimize Float#rationalize

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* rational.c (rb_flt_rationalize{,_with_prec},float_rationalize):
  optimize Float#rationalize.
  Author: Tadashi Saito <tad.a.digger@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56752 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit is contained in:
mrkn 2016-11-12 12:14:10 +00:00
parent 81f16bf32f
commit bdfd436f78
1 changed files with 16 additions and 15 deletions
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31
rational.c
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@ -2093,7 +2093,7 @@ rb_flt_rationalize_with_prec(VALUE flt, VALUE prec)
b = f_add(flt, e);
if (f_eqeq_p(a, b))
return f_to_r(flt);
return float_to_r(flt);
nurat_rationalize_internal(a, b, &p, &q);
return rb_rational_new2(p, q);
@ -2105,33 +2105,33 @@ rb_flt_rationalize(VALUE flt)
VALUE a, b, f, n, p, q;
float_decode_internal(flt, &f, &n);
if (f_zero_p(f) || f_positive_p(n))
return rb_rational_new1(f_lshift(f, n));
if (INT_ZERO_P(f) || FIX2INT(n) >= 0)
return rb_rational_new1(rb_int_lshift(f, n));
#if FLT_RADIX == 2
{
VALUE two_times_f, den;
two_times_f = f_mul(TWO, f);
den = f_lshift(ONE, f_sub(ONE, n));
two_times_f = rb_int_mul(TWO, f);
den = rb_int_lshift(ONE, rb_int_minus(ONE, n));
a = rb_rational_new2(f_sub(two_times_f, ONE), den);
b = rb_rational_new2(f_add(two_times_f, ONE), den);
a = rb_rational_new2(rb_int_minus(two_times_f, ONE), den);
b = rb_rational_new2(rb_int_plus(two_times_f, ONE), den);
}
#else
{
VALUE radix_times_f, den;
radix_times_f = f_mul(INT2FIX(FLT_RADIX), f);
den = f_expt(INT2FIX(FLT_RADIX), f_sub(ONE, n));
radix_times_f = rb_int_mul(INT2FIX(FLT_RADIX), f);
den = rb_int_pow(INT2FIX(FLT_RADIX), rb_int_minus(ONE, n));
a = rb_rational_new2(f_sub(radix_times_f, INT2FIX(FLT_RADIX - 1)), den);
b = rb_rational_new2(f_add(radix_times_f, INT2FIX(FLT_RADIX - 1)), den);
a = rb_rational_new2(rb_int_minus(radix_times_f, INT2FIX(FLT_RADIX - 1)), den);
b = rb_rational_new2(rb_int_plus(radix_times_f, INT2FIX(FLT_RADIX - 1)), den);
}
#endif
if (f_eqeq_p(a, b))
return f_to_r(flt);
if (nurat_eqeq_p(a, b))
return float_to_r(flt);
nurat_rationalize_internal(a, b, &p, &q);
return rb_rational_new2(p, q);
@ -2155,9 +2155,10 @@ static VALUE
float_rationalize(int argc, VALUE *argv, VALUE self)
{
VALUE e;
double d = RFLOAT_VALUE(self);
if (f_negative_p(self))
return f_negate(float_rationalize(argc, argv, f_abs(self)));
if (d < 0.0)
return nurat_negate(float_rationalize(argc, argv, DBL2NUM(-d)));
rb_scan_args(argc, argv, "01", &e);