[PATCH 14/25] math: Use acosh from CORE-MATH

[Wilco Dijkstra]

Hi,

>>> +  if (ix < 0x4190000000000000)
>>
>> Do we need a UL suffix here (and other places)?
>
> Probably a mistake. Adhemerval used UINT64_C elsewhere. And that would
> be correct here as well.

Since we force use of -std=gnu11, we don't really need a suffix [1] unless we
need to force the type to unsigned or to a wider type. Eg. you need to write
1ULL << x if you want a 64-bit shift.

Note this code does both the above as well as this:

+      if (__glibc_unlikely (u >= (uint64_t) 0x7ff0000000000000ull))

So it would be good to standardize all this a bit. Many existing inline 64-bit constants
are simply sign, exponent and mantissa masks, for which we already have defines. 

[1] http://en.cppreference.com/w/c/language/integer_constant.html

Cheers,
Wilco