newlib printf %f BUG

[J. Johnston]

Ted Merrill wrote:
> 
> I hope this is where to report bugs.
> 
> Using both newlib-1.8.2 and newlib-1.9.0 compiled using gcc for ARM/thumb
> architecture using gcc 3.0,
> a bug in printf floating point formatting is seen for some numbers.
> 
> Sample code:
> 
> void MathTest2(void)
> {
>     /* This tests a bug we found in newlib 1.8.2
>     */
>     double R = 3.4263125;
>     printf("%.6f\n", R );
> }
>

Ted,

  Have you tried this using the latest newlib sources?  Newlib 1.9.0 is simply
a snapshot.  A number of fixes have been applied to these sources, including
at least one fix to printf %f.

  Are you specifying any special options on the compile/link?  If so,
you should consider doing a unified source-tree build so that gcc can
locate the proper newlib based on your options.

  Using the latest newlib sources and the armulator simulator, I am able to
get the accompanying test case to print the correct value.  I am using default
options and because I did not do a unified build, I had to copy the crt0.o 
file to my test directory.  My arm-elf-gcc is slightly ahead of yours.

Regards,

-- Jeff J.

#include <stdio.h>

int main()
{
    /* This tests a bug we found in newlib 1.8.2
    */
    double R = 3.4263125;
    printf("%.6f\n", R );
}
    
>% arm-elf-run a.out
3.426312