AC_C_LONG_DOUBLE is obsolescent.

[Bob Friesenhahn]

The news for Autoconf 2.62 says this:

** AC_C_LONG_DOUBLE is obsolescent.
   The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
   tests for problems that are so old that it is no longer of
   practical importance on current systems.  New programs need not use
   AC_C_LONG_DOUBLE.  We have no current plans to remove it.

I am confused since I don't see how the usefullness of this test can 
be obsolescent.  On some systems the useful range of 'long double' is 
the same as 'double' while on other systems the range is much greater. 
The range is sometimes selected by a compile time option. The useful 
range does not always match that suggested by sizeof(long double). My 
application makes use of this test.

I am also confused by the use of the term "current systems" since 
perhaps it means some specific version of Linux/glibc rather than the 
set of still running systems on which an autoconf configure script may 
be executed.  If autoconf is targeted toward "current systems" then a 
definition of what this means (i.e. the criteria for which systems are 
no longer supported) should be documented.

Can someone please comment as to why it is felt that this test is 
obsolescent?

Thanks,

Bob
======================================
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/