Issue #13078 has been updated by _ wanabe.


The accuracy of `Rational(a, b).to_f` seems to be due to reduction of fraction.
How about using Reational object, or its internal function `f_gcd()` and `f_idiv()`?

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Bug #13078: with Integer a and b, a.fdiv(b) sometimes inaccurate than Rational(a, b).to_f
https://bugs.ruby-lang.org/issues/13078#change-62296

* Author: Makoto Kishimoto
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: 
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
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For example,

~~~
a = 3
b = 0x20_0000_0000_0001
p a.fdiv(b)
p Rational(a, b).to_f

#=>
3.3306690738754696e-16
3.330669073875469e-16
~~~
I'm hacking to solve this problem, see diff view.
https://github.com/ruby/ruby/compare/trunk...metanest:fdiv_spike



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