--- /dev/null
+# floatparam.m4 serial 1
+dnl Copyright (C) 2005 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+AC_DEFUN([CL_FLOATPARAM_CROSS],
+[
+ AC_REQUIRE([CL_LONGDOUBLE])
+ cl_machine_file_h=$1
+ {
+ echo "/* Rounding modes, for use below */"
+ echo "#define rounds_to_nearest 0 /* 0.5 ulp */"
+ echo "#define rounds_to_zero 1 /* 1 ulp */"
+ echo "#define rounds_to_infinity 2 /* 1 ulp */"
+ echo "#define rounds_to_minus_infinity 3 /* 1 ulp */"
+ echo
+ for type in float double "`if test $cl_cv_c_longdouble = yes; then echo 'long double'; fi`"; do
+ if test -n "$type"; then
+ epsilon_bits=-1; y="($type)1.0"
+ while true; do
+ AC_TRY_COMPILE([],
+ [typedef int verify[2*(
+ (($type)(($type)1.0 + ($type)($y)) == ($type)1.0)
+ || ($type)(($type)(($type)1.0 + ($type)($y)) - ($type)1.0) != ($type)($y)
+ ) - 1];],
+ [break;])
+ epsilon_bits=`expr $epsilon_bits + 1`; y="$y * ($type)0.5"
+ done
+ negepsilon_bits=-1; y="($type)-1.0"
+ while true; do
+ AC_TRY_COMPILE([],
+ [typedef int verify[2*(
+ (($type)(($type)1.0 + ($type)($y)) == ($type)1.0)
+ || ($type)(($type)(($type)1.0 + ($type)($y)) - ($type)1.0) != ($type)($y)
+ ) - 1];],
+ [break;])
+ negepsilon_bits=`expr $negepsilon_bits + 1`; y="$y * ($type)0.5"
+ done
+ echo "/* Properties of type \`$type': */"
+ echo "/* Largest n for which 1+2^(-n) is exactly represented is $epsilon_bits. */"
+ echo "/* Largest n for which 1-2^(-n) is exactly represented is $negepsilon_bits. */"
+ if test `expr $negepsilon_bits '<=' $epsilon_bits` = 1; then
+ echo "#error \"No exponent jump at 1.0 for type $type!\""
+ else
+ if test `expr $negepsilon_bits '>' $epsilon_bits + 1` = 1; then
+ echo "/* Base for type '$type' is 2^"`expr $negepsilon_bits - $epsilon_bits`
+ fi
+ echo "#define "`echo $type | sed -e 's, ,_,g'`"_mant_bits "`expr $epsilon_bits + 1`
+ fi
+ x="($type)1.0"
+ i=$epsilon_bits
+ while test $i != 0; do
+ x="$x * ($type)0.5"
+ i=`expr $i - 1`
+ done
+ x="($type)($x)"
+ y1="($type)(($type)1.0 + ($type)5.0*$x)"
+ y2="($type)(($type)1.0 + ($type)6.0*$x)"
+ ys1="($type)(($type)1.0 + ($type)5.4*$x)"
+ ys2="($type)(($type)1.0 + ($type)5.6*$x)"
+ z1="($type)(($type)-1.0 + ($type)(-5.0)*$x)"
+ z2="($type)(($type)-1.0 + ($type)(-6.0)*$x)"
+ zs1="($type)(($type)-1.0 + ($type)(-5.4)*$x)"
+ zs2="($type)(($type)-1.0 + ($type)(-5.6)*$x)"
+ rounds=
+ if test -z "$rounds"; then
+ AC_TRY_COMPILE([],
+ [typedef int verify[2*(
+ $ys1 == $y1 && $ys2 == $y2 && $zs1 == $z1 && $zs2 == $z2
+ ) - 1];],
+ [rounds=rounds_to_nearest])
+ fi
+ if test -z "$rounds"; then
+ AC_TRY_COMPILE([],
+ [typedef int verify[2*(
+ $ys1 == $y1 && $ys2 == $y1 && $zs1 == $z1 && $zs2 == $z1
+ ) - 1];],
+ [rounds=rounds_to_zero])
+ fi
+ if test -z "$rounds"; then
+ AC_TRY_COMPILE([],
+ [typedef int verify[2*(
+ $ys1 == $y2 && $ys2 == $y2 && $zs1 == $z1 && $zs2 == $z1
+ ) - 1];],
+ [rounds=rounds_to_infinity])
+ fi
+ if test -z "$rounds"; then
+ AC_TRY_COMPILE([],
+ [typedef int verify[2*(
+ $ys1 == $y1 && $ys2 == $y1 && $zs1 == $z2 && $zs2 == $z2
+ ) - 1];],
+ [rounds=rounds_to_minus_infinity])
+ fi
+ if test -n "$rounds"; then
+ echo "#define "`echo $type | sed -e 's, ,_,g'`"_rounds $rounds"
+ else
+ echo "#error \"Unknown rounding mode for type $type!\""
+ fi
+ echo
+ fi
+ done
+ dnl Words-in-a-double endianness test. Note that, assuming IEEE 754 format,
+ dnl 2.5479915693083957 = { 0x40 0x04 0x62 0x49 0x67 0x65 0x4E 0x64 } ..bIgeNd
+ dnl 1.4396527506122064e164 = { 0x62 0x04 0x00 0x00 0x4E 0x65 0x67 0x49 } b...NegI
+ dnl 2.5495230282078065 = { 0x40 0x04 0x65 0x6C 0x54 0x54 0x69 0x4C } ..elTTiL
+ dnl 1.4139248369879473e214 = { 0x6C 0x65 0x00 0x00 0x4C 0x69 0x54 0x54 } le..LiTT
+ double_wordorder_bigendian_p=
+ AC_TRY_COMPILE([double a[9] = {
+ 0, 2.5479915693083957, 0, 1.4396527506122064e164,
+ 0, 2.5495230282078065, 0, 1.4139248369879473e214,
+ 0 };], [], [
+ if grep LiTTle conftest.$ac_objext >/dev/null ; then
+ double_wordorder_bigendian_p=0
+ else
+ if grep bIgeN conftest.$ac_objext >/dev/null ; then
+ double_wordorder_bigendian_p=1
+ fi
+ fi])
+ if test -n "$double_wordorder_bigendian_p"; then
+ echo "#define double_wordorder_bigendian_p $double_wordorder_bigendian_p"
+ else
+ echo "/* Dazed and confused! Better not define anything. */"
+ fi
+ echo
+ } > "$cl_machine_file_h"
+])