Aw: Re: TR1 Special Math

Joseph Myers
Thu Nov 19 22:07:00 GMT 2015

On Thu, 19 Nov 2015, Ed Smith-Rowland wrote:

> Testing coverage is growing.
> I starting to build check_inf tests for everyone (but they aren't in the
> patch.
> I'll look at musl to see how you do check_denorm, etc.

FWIW, in glibc I've systematically put special cases and a representative 
range of input values in auto-libm-test-in (where the test inputs and 
mathematical results are finite, but possibly overflowing / underflowing) 
/ (where not all finite).  Random test generation has also 
been done with both mpcheck and ad hoc scripts that put random inputs in 
auto-libm-test-in before regenerating auto-libm-test-out and running the 
testsuite, in order to find cases with large errors or spurious or missing 
exceptions (those cases then being added to auto-libm-test-in when the 
bugs are fixed).  This all relies heavily on having MPFR / MPC support for 
the functions in question in order to compute the ideal correctly rounded 
results for all rounding modes (so if new functions were added to glibc, 
it would be a very good idea to add them to MPFR / MPC first).

Joseph S. Myers

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