On Thu, 14 Oct 2021 at 16:21, frijolithedog 1 via Gcc-help <
gcc-help@xxxxxxxxxxx> wrote:
> I am having a C programing problem where <= is interpreted as < when using
> GCC 11.2.0
>
> I was debugging a larger program which I broke down into smaller sections
> of code and I noticed
> the following code was not working correctly:
>
> #include <stdio.h>
> #include <math.h>
> #include <float.h>
>
> int main(void)
> {
> float n, step;
>
> step = 0.1;
>
> for (n = 2; n <= 10; n = n + step )
> printf("%3.4f\n", n ); /* This stops at
> 9.9000 and not at 10.0000 */
>
> }
>
> I tried the above code only using the following include statement
> #include <stdio.h>
> but the result was the same.
>
See
https://stackoverflow.com/questions/21895756/why-are-floating-point-numbers-inaccurate
and hundreds of other pages explaining the properties of floating-point
numbers:
https://docs.python.org/3/tutorial/floatingpoint.html
https://en.wikipedia.org/wiki/Floating-point_arithmetic#Representable_numbers,_conversion_and_rounding
For the full story:
https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
