SV: Bug in printf ?

Thu Jun 30 12:06:00 GMT 2005

----Original Message----
>From: haro@kgt.co.jp
>Sent: 30 June 2005 12:21

> From: "Peter J. Acklam" <pjacklam at online no>
> Date: 2005年6月30日 13:06:51 +0200 (CEST)
>>>>>>> I'm seeing small bug in printf implementation.
>>>>>> What bug? I didn't see anything unexpected.
>>>>>> Peter
>> Hi Peter,
>> How come "0.125" gets printed as "0.12", and not "1.3"?
>> Haro

 Absolutely, there's a rounding error of some sort. Compare the difference
when compiling the testcase with -mno-cygwin (i.e. using mingw maths lib):
dk@mace /test/signed/lr2> cat aaa.c
#include <stdio.h>
int main(int argc, const char **argv)
{
 printf("%0.2f\n", 0.105);
 printf("%0.2f\n", 0.115);
 printf("%0.2f\n", 0.125);
 printf("%0.2f\n", 0.135);
 return 0;
}
dk@mace /test/signed/lr2> gcc -O0 -g aaa.c -o aaa-c
dk@mace /test/signed/lr2> ./aaa-c.exe
0.10
0.12
0.12
0.14
dk@mace /test/signed/lr2> gcc -O0 -g -mno-cygwin aaa.c -o aaa-m
dk@mace /test/signed/lr2> ./aaa-m.exe
0.11
0.12
0.13
0.14
dk@mace /test/signed/lr2>
 cheers,
 DaveK
-- 
Can't think of a witty .sigline today....
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