?RCS:
?RCS: Copyright (c) 2012 Raphael Manfredi
?RCS: 
?RCS: You may redistribute only under the terms of the Artistic License,
?RCS: as specified in the README file that comes with the distribution.
?RCS: You may reuse parts of this distribution only within the terms of
?RCS: that same Artistic License; a copy of which may be found at the root
?RCS: of the source tree for dist 4.0.
?RCS:
?MAKE:d_ieee754 ieee754_byteorder: cat contains echo n c \
	Myread Oldconfig Loc Setvar +cc +ccflags rm _o
?MAKE:	-pick add $@ %<
?S:d_ieee754:
?S:	This variable conditionally defines the USE_IEEE754_FLOAT symbol,
?S:	which indicates to the C program that floats and doubles use the
?S:	IEEE-754 format.
?S:.
?S:ieee754_byteorder:
?S:	This variable holds the IEEE float byte order. In the following, larger
?S:	digits indicate more significance.  The variable byteorder is either 4321
?S:	on a big-endian machine, or 1234 on a little-endian one.
?S:	cannot figure it out.
?S:.
?C:USE_IEEE754_FLOAT:
?C:	When defined, this symbol indicates that float and double values are
?C:	stored using the IEEE-754 floating point format.  See IEEE754_BYTEORDER
?C:	to determine the endianness in case these values need to be serialized.
?C:.
?C:IEEE754_BYTEORDER:
?C:	This symbol holds the hexadecimal constant defined in ieee754_byteorder,
?C:	i.e. 1234 for little-endian or 4321 for big-ending floats.  It is 0 when
?C:	floats are not stored in IEEE-754 format.
?C:.
?H:#$d_ieee754 USE_IEEE754_FLOAT
?H:#define IEEE754_BYTEORDER 0x$ieee754_byteorder	/* large digits for MSB */
?H:.
?T:order
?F:!str !try.c
?LINT:set d_ieee754
: check for ieee754 float and their endianness
?X:
?X: An idea from Guido Draheim <Guido.Draheim@gmx.de> checking the endianness
?X: without actually executing code, which allows cross-compiling.
?X:
echo " "
$echo $n "Checking IEEE-754 float byte-ordering...$c" >&4
$cat >try.c <<'EOCP'
float ascii_le[] = {
	3223.213134765625, 6.8273612896518898e-07, 1.9753562586009612e+31, 0 };
float ascii_be[] = {
	865942.3125, 6.7652519659605424e+22, 1.9695089292781631e-07, 0 };
EOCP
order=0
val=''
if $cc -c $ccflags try.c >/dev/null 2>&1; then
	if $contains ISieee754Sys try$_o >/dev/null 2>&1; then
		val=$define
		order=4321
	elif $contains isIEEE754Sys try$_o >/dev/null 2>&1; then
		val=$define
		order=1234
?X:
?X: On Solaris, "grep" does not work on binary files -- use strings.
?X:
	else
		strings try$_o >str 2>/dev/null
		if $contains ISieee754Sys str >/dev/null 2>&1; then
			val=$define
			order=4321
		elif $contains isIEEE754Sys str >/dev/null 2>&1; then
			val=$define
			order=1234
		else
			val=$undef
		fi
		$rm -f str
	fi
fi
set d_ieee754
eval $setvar
case "$order" in
0)    echo " not using IEEE-754 here." >&4;;
1234) echo " little-endian." >&4;;
4321) echo " big-endian." >&4;;
esac
ieee754_byteorder=$order
$rm -f try.c try$_o