On Fri, 9 Feb 2007, Andy Dougherty wrote:
> I'll send the metaconfig unit separately in a follow-up message.
Here's my proposed d_signbit.U unit.
?RCS: $Id$
?RCS:
?RCS: You may distribute under the terms of either the GNU General Public
?RCS: License or the Artistic License, as specified in the README file.
?RCS:
?MAKE:d_signbit: nvtype Compile Setvar cat run rm echo i_math i_sunmath
?MAKE: -pick add $@ %<
?S:d_signbit:
?S: This variable conditionally defines the HAS_SIGNBIT symbol, which
?S: indicates to the C program that the signbit() routine is available
?S: and safe to use with perl's intern NV type.
?S:.
?C:HAS_SIGNBIT:
?C: This symbol, if defined, indicates that the signbit routine is
?C: available to check if the given number has the sign bit set.
?C: This should include correct testing of -0.0. This will only be set
?C: if the signbit() routine is safe to use with the NV type used internally
?C: in perl. Users should call Perl_signbit(), which will be #defined to
?C: the system's signbit() function or macro if this symbol is defined.
?C:.
?H:#$d_signbit HAS_SIGNBIT /**/
?H:.
?LINT:set d_signbit d_use_signbit
: see if signbit exists
$echo $n "Checking to see if you have signbit() available to work on $nvtype...
$c" >&4
$cat >try.c <<EOCP
#$i_math I_MATH
#$i_sunmath I_SUNMATH
#ifdef I_MATH
# include <math.h>
#endif
#ifdef I_SUNMATH /* Solaris special math library */
# include <sunmath.h>
#endif
#define NV $nvtype
int main(int argc, char **argv)
{
NV x = 0.0;
NV y = -0.0;
if ((signbit(x) == 0) && (signbit(y) != 0))
return 0;
else
return 1;
}
EOCP
val="$undef"
set try
if eval $compile; then
if $run ./try; then
$echo "Yes." >&4
val="$define"
else
$echo "Signbit seems to be available, but doesn't work as I expected."
$echo "I won't use it." >&4
val="$undef"
fi
else
$echo "Nope." >&4
dflt="$undef"
fi
set d_signbit
eval $setvar
$rm -f try.* try
--
Andy Dougherty [EMAIL PROTECTED]
Dept. of Physics
Lafayette College, Easton PA 18042
