Re: [Bug-gsl] bug in gsl_eigen_hermv

[Brian Gough]

At Mon, 12 Nov 2007 19:43:43 -0700 (MST),
Matthew B. Hastings wrote:
> I then tried it with set env GSL_IEEE_MODE round-to-nearest and got
> 
> gsl: fp-darwin.c:70: ERROR: powerpc does not support the denormalized
> operand exception. Use 'mask-denormalized' to work around this.
> Default GSL error handler invoked.
> 
> so I also tried set env GSL_IEEE_MODE mask-denormalized.  In this case,
> the program ran, returning the nans, but without trapping any floating
> point exception.  I have not used gsl_ieee_env_setup() to do this before,
> so please let me know if I am doing anything wrong.  I compiled the code
> with the -g flag.

I'm not sure why the exceptions aren't generated(*) but if you can figure
out how to enable them this will be the best way to find the bug,
because it will lead you directly to the point of failure.  Maybe the
documentation on your machine will give some more information.

-- 
Brian Gough

* The code for MacOS was contributed, I didn't write it myself --
  looking at ieee-utils/fp-darwin.c briefly it looks like it only
  turns off exceptions instead of turning them on.  Each if statement
  probably needs an "else fp_scr.XX = 1 ;" on it.