Re: TR1 Math Special Functions

[Ed Smith-Rowland <3dw4rd at verizon dot net>]

Paolo Carlini wrote:
> Hi again,
>
> > Here is another drop.
> >
> > It is completely reworked relative to the last one.
>
> IMHO, very good progress, indeed.
>
> I just finished regtesting on x86_64-linux and got the following 4 
> failures:
>
> check_value.exe: 
> */tr1/5_numerical_facilities/special_functions/01_assoc_laguerre/check_value.cc:2143: 
> void test049() [with Tp = double]: Assertion `max_abs_frac < 
> Tp(0.002)' failed.
> FAIL: 
> tr1/5_numerical_facilities/special_functions/01_assoc_laguerre/check_value.cc 
> execution test
>
> check_value.exe: 
> */tr1/5_numerical_facilities/special_functions/17_hyperg/check_value.cc:4336: 
> void test086() [with Tp = double]: Assertion `max_abs_frac < 
> Tp(0.002)' failed.
> FAIL: 
> tr1/5_numerical_facilities/special_functions/17_hyperg/check_value.cc 
> execution test
>
> check_value.exe: 
> */tr1/5_numerical_facilities/special_functions/18_laguerre/check_value.cc:400: 
> void test007() [with Tp = double]: Assertion `max_abs_frac < 
> Tp(0.002)' failed.
> FAIL: 
> tr1/5_numerical_facilities/special_functions/18_laguerre/check_value.cc 
> execution test
>
> check_value.exe: 
> */tr1/5_numerical_facilities/special_functions/22_sph_legendre/check_value.cc:1202: 
> void test022() [with Tp = double]: Assertion `max_abs_frac < 
> Tp(2.0000000000000016e-14)' failed.
> FAIL: 
> tr1/5_numerical_facilities/special_functions/22_sph_legendre/check_value.cc 
> execution test
I have some fixed.  One or two I'm going to have to XFAIL for now.
> Besides that, before we can do the first commit, I can see one blocker 
> issue (really, because affects the bootstrap itself, on some targets): 
> you are using in many places std::isnan, which, in fact, is only 
> available if the target supports the C99 math facilities (grep 
> tr1/cmath about isnan & co, about that). What do you suggest? As a 
> stopgap solution we could also disable completely the affected code 
> (but I appreciate your efforts with tgamma, elsewhere... )
Am I allowed to use this:
     else if (::__gnu_cxx::__capture_isnan(__alpha))
       return std::numeric_limits<_Tpa>::quiet_NaN();

> Otherwise, I see un-uglified names in struct __numeric_constants, it 
> would be nice if you could take care of that and well, of course 
> double check that you are not using unconditionally any other C99 
> facility (configuring --disable-c99 should help here). But I can take 
> care of these trivial things, in order to speed-up the process, if you 
> are willing to look into the above more substantive ones.
I'm now preceding the static function names with two underscores.
> Many thanks for your patience with the various issues, I think we are 
> quickly converging to code ready for the first commit, really. I look 
> forward to the next, i.e., last, iteration...
>
> Paolo.