[libcxx+newlib] nexttoward{f,l,} shims for _LDBL_EQ_DBL systems

[Craig Howland]

On 09/23/2014 04:33 PM, Jonathan Roelofs wrote:
> Please see the attached patch.
>
Needs a ChangeLog entry.  Missing the patch for libm/common/Makefile.am.

Operationally, all looks OK, but aesthetically, the use of casting is 
inconsistent.  For example:

+long double
+nexttowardl (long double x, long double y)
+{
+  return nextafter((double)x, (double)y);
+}

The x and y arguments are cast to double to pass to nextafter(), but the return 
value is not cast to long double.  It works OK, but could be confusing.  Are the 
casts intended to highlight the spots where the double/long double equality is 
required?  If so, it would probably be better to either cast in all places where 
it is theoretically needed, or to just leave them out.  The other existing 
functions of this style left all of them out (i.e. no casts from ld to d or d to 
ld)--see, for example, libm/common/nextafterl.c.  I suggest that the precedent 
is the better way.

Craig