Re: Testing newlib

[Sergei Gavrikov <sergei.gavrikov@gmail.com>]

On Mon, 25 Jul 2011, Visar Zejnullahu wrote:

> Hi.
> 
> As announced here:
> http://sourceware.org/ml/ecos-devel/2011-07/msg00003.html we are working
> on a port of Newlib's single precision floating point math library
> (float vs double...).
> 
> I know part of the questions should be addressed to the Newlib's mailing
> list (which I have done as well), but I am asking help on the Ecos part
> of the problems.

Hi Visar,

[cut set of Q that I do not have the expertise]

> And lastly, about the gamma function - I've used the tests provided
> from Newlib, and when I try to compile the test files about this
> function, I get the error
> ecos/packages/language/c/libm/current/src/double/ieee754-api/w_gamma.c:99:
> undefined reference to `signgam'. Can anyone help on this?

Look, please, at ecos math.h:160

  #ifdef CYGSEM_LIBM_THREAD_SAFE_GAMMA_FUNCTIONS

  // FIXME: these need to be documented and signgam mentioned as non-ISO
  // This returns the address of the signgam variable used by the gamma*() and
  // lgamma*() functions
  externC int *
  cyg_libm_get_signgam_p( void );

  #define signgam (*cyg_libm_get_signgam_p())


I think you will get it. Also, the next point to look on

libm.cdl:125:cdl_option CYGSEM_LIBM_THREAD_SAFE_GAMMA_FUNCTIONS

IMHO, the option's description attribute is the very informative.


Sergei