It was disabled because lack of reference implementation. However the
reference implementation exists. Then no reason to start testing these
functions.
In binary_float.cpp, copysign is special cased. All the reference
functions there take double arguments, except for reference_copysign
which takes float. This commit copies that approach to special case
copysign in binary_double.cpp as well: all the reference functions there
take long double arguments, but this commit changes reference_copysignl
to take double. The rationale for this in binary_float applies equally
to binary_double: conversions of NAN are not required to preserve its
sign bit. On architectures where conversion of NAN resets the sign bit,
copysign fp64 would return incorrect reference results.
* Add relaxed tests for functions (in an implementation that uses
derived functions) that define an absolute ULP error requirement, but
were not tested in the current conformance suite
* acos
* asin
* atan
* cospi
* sinpi
* log10
