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Re: [Mingw-users] msvcrt printf bug




On Saturday, January 14, 2017 10:17 AM, KHMan wrote:
> On 1/14/2017 10:02 PM, tei.andu@xxxxxxxxxxxx wrote:
>>
>> Hello,
>> I encountered a loss of precision printing a float with C printf.
>> For values greater than or equal to 1.743397235870361328125 * 2 ^
>> 59 (0x5D5F27A4) the printed value is slightly wrong. The error
>> increases with increasing input.

> The output is fine. When the 32 bit float is converted into 64
> bits and then printed, it should be accurate up to about 17
> digits. I would not trust anything beyond 17 digits with my
> favorite teddy bear.
>
> Why should one expect 19 digits of precision? Also, one should not
> expect 8087's extended precision registers to be used anymore
> unless it is explicitly required.

You have skillfully avoided addressing the fact that it works as the
original poster expects with glibc 2.2.5 (tested on Linux / glibc 2.19).

Regards,
John Brown..
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