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Diffstat (limited to 'mcon/U/d_ieee754.U')
| -rw-r--r-- | mcon/U/d_ieee754.U | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/mcon/U/d_ieee754.U b/mcon/U/d_ieee754.U new file mode 100644 index 0000000..1abb0aa --- /dev/null +++ b/mcon/U/d_ieee754.U @@ -0,0 +1,88 @@ +?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 + |