[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: AC_C_LONG_DOUBLE is obsolescent.

From: Eric Blake
Subject: Re: AC_C_LONG_DOUBLE is obsolescent.
Date: Wed, 9 Apr 2008 22:39:48 +0000 (UTC)
User-agent: Loom/3.14 (

Andreas Schwab <schwab <at>> writes:

> Eric Blake <ebb9 <at>> writes:
> > Most C89 compilers these days provide long double at least as an
> > extension,
> long double is not an extension.  Did you mistake it with long long?

Indeed.  A closer look at C89 requires 'long double'.  Therefore, 
AC_TYPE_LONG_DOUBLE should always succeed.

Meanwhile, I'm wondering if AC_TYPE_LONG_DOUBLE_WIDER has a bug - there are 
some platforms (OpenBSD 4.0 and BeOS, for example), where <float.h> is buggy, 
and the information about 'long double' is copied from the information 
about 'double', even though 'long double' really is a wider type.  So on those 
platforms, AC_TYPE_LONG_DOUBLE_WIDER may be coming up with the wrong answer 
because of the buggy header.

Eric Blake

reply via email to

[Prev in Thread] Current Thread [Next in Thread]