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# Autoconf macros for the GNU MP Library.
# Copyright (C) 2000-2014 Free Software Foundation, Inc.
#
# Copyright (C) 2014 Peter Breitenlohner <tex-live@tug.org>
# Extracted from gmp-6.0.0/acinclude.m4 and adapted for TeX Live.
#
# This file is free software; the copyright holders
# give unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
# GMP_C_DOUBLE_FORMAT
# -------------------
# Determine the floating point format.
#
# The object file is grepped, in order to work when cross compiling. A
# start and end sequence is included to avoid false matches, and allowance
# is made for the desired data crossing an "od -b" line boundary. The test
# number is a small integer so it should appear exactly, no rounding or
# truncation etc.
#
# "od -b", incidentally, is supported even by Unix V7, and the awk script
# used doesn't have functions or anything, so even an "old" awk should
# suffice.
#
# The C code here declares the variable foo as extern; without that, some
# C++ compilers will not put foo in the object file.
AC_DEFUN([GMP_C_DOUBLE_FORMAT], [dnl
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_PROG_AWK])
AC_CACHE_CHECK([format of `double' floating point],
[gmp_cv_c_double_format],
[gmp_cv_c_double_format=unknown
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
struct foo {
char before[8];
double x;
char after[8];
};
extern struct foo foo;
struct foo foo = {
{ '\001', '\043', '\105', '\147', '\211', '\253', '\315', '\357' },
-123456789.0,
{ '\376', '\334', '\272', '\230', '\166', '\124', '\062', '\020' },
};
]])],
[cat >conftest.awk <<\EOF
_gmp_double_awk
EOF
gmp_cv_c_double_format=`od -b conftest.$ac_objext | $AWK -f conftest.awk`
AS_CASE([$gmp_cv_c_double_format],
[unknown*],
[echo "cannot match anything, conftest.$ac_objext contains" >&AS_MESSAGE_LOG_FD
od -b conftest.$ac_objext >&AS_MESSAGE_LOG_FD])],
[AC_MSG_WARN([oops, cannot compile test program])])
rm -f conftest.awk])
AH_VERBATIM([HAVE_DOUBLE],
[/* Define one of the following to 1 for the format of a `double'.
If your format is not among these choices, or you don't know what it is,
then leave all undefined.
IEEE_LITTLE_SWAPPED means little endian, but with the two 4-byte halves
swapped, as used by ARM CPUs in little endian mode. */
#undef HAVE_DOUBLE_IEEE_BIG_ENDIAN
#undef HAVE_DOUBLE_IEEE_LITTLE_ENDIAN
#undef HAVE_DOUBLE_IEEE_LITTLE_SWAPPED
#undef HAVE_DOUBLE_VAX_D
#undef HAVE_DOUBLE_VAX_G
#undef HAVE_DOUBLE_CRAY_CFP])
AS_CASE([$gmp_cv_c_double_format],
["IEEE big endian"],
[AC_DEFINE([HAVE_DOUBLE_IEEE_BIG_ENDIAN], 1)],
["IEEE little endian"],
[AC_DEFINE([HAVE_DOUBLE_IEEE_LITTLE_ENDIAN], 1)],
["IEEE little endian, swapped halves"],
[AC_DEFINE([HAVE_DOUBLE_IEEE_LITTLE_SWAPPED], 1)],
["VAX D"],
[AC_DEFINE([HAVE_DOUBLE_VAX_D], 1)],
["VAX G"],
[AC_DEFINE([HAVE_DOUBLE_VAX_G], 1)],
["Cray CFP"],
[AC_DEFINE([HAVE_DOUBLE_CRAY_CFP], 1)],
["bad ARM software floats"], [],
[unknown*],
[AC_MSG_WARN([Could not determine float format.])
AC_MSG_WARN([Conversions to and from "double" may be slow.])],
[AC_MSG_WARN([oops, unrecognised float format: $gmp_cv_c_double_format])])
]) # GMP_C_DOUBLE_FORMAT
# _gmp_double_awk
# ---------------
# Internal subroutine defining contents of conftest.awk.
m4_define([_gmp_double_awk], [[
BEGIN {
found = 0
}
{
for (f = 2; f <= NF; f++)
{
for (i = 0; i < 23; i++)
got[i] = got[i+1];
got[23] = $f;
# match the special begin and end sequences
if (got[0] != "001") continue
if (got[1] != "043") continue
if (got[2] != "105") continue
if (got[3] != "147") continue
if (got[4] != "211") continue
if (got[5] != "253") continue
if (got[6] != "315") continue
if (got[7] != "357") continue
if (got[16] != "376") continue
if (got[17] != "334") continue
if (got[18] != "272") continue
if (got[19] != "230") continue
if (got[20] != "166") continue
if (got[21] != "124") continue
if (got[22] != "062") continue
if (got[23] != "020") continue
saw = " (" got[8] " " got[9] " " got[10] " " got[11] " " got[12] " " got[13] " " got[14] " " got[15] ")"
if (got[8] == "000" && \
got[9] == "000" && \
got[10] == "000" && \
got[11] == "124" && \
got[12] == "064" && \
got[13] == "157" && \
got[14] == "235" && \
got[15] == "301")
{
print "IEEE little endian"
found = 1
exit
}
# Little endian with the two 4-byte halves swapped, as used by ARM
# when the chip is in little endian mode.
#
if (got[8] == "064" && \
got[9] == "157" && \
got[10] == "235" && \
got[11] == "301" && \
got[12] == "000" && \
got[13] == "000" && \
got[14] == "000" && \
got[15] == "124")
{
print "IEEE little endian, swapped halves"
found = 1
exit
}
# gcc 2.95.4 on one GNU/Linux ARM system was seen generating 000 in
# the last byte, whereas 124 is correct. Not sure where the bug
# actually lies, but a running program didn't seem to get a full
# mantissa worth of working bits.
#
# We match this case explicitly so we can give a nice result message,
# but we deliberately exclude it from the normal IEEE double setups
# since it's too broken.
#
if (got[8] == "064" && \
got[9] == "157" && \
got[10] == "235" && \
got[11] == "301" && \
got[12] == "000" && \
got[13] == "000" && \
got[14] == "000" && \
got[15] == "000")
{
print "bad ARM software floats"
found = 1
exit
}
if (got[8] == "301" && \
got[9] == "235" && \
got[10] == "157" && \
got[11] == "064" && \
got[12] == "124" && \
got[13] == "000" && \
got[14] == "000" && \
got[15] == "000")
{
print "IEEE big endian"
found = 1
exit
}
if (got[8] == "353" && \
got[9] == "315" && \
got[10] == "242" && \
got[11] == "171" && \
got[12] == "000" && \
got[13] == "240" && \
got[14] == "000" && \
got[15] == "000")
{
print "VAX D"
found = 1
exit
}
if (got[8] == "275" && \
got[9] == "301" && \
got[10] == "064" && \
got[11] == "157" && \
got[12] == "000" && \
got[13] == "124" && \
got[14] == "000" && \
got[15] == "000")
{
print "VAX G"
found = 1
exit
}
if (got[8] == "300" && \
got[9] == "033" && \
got[10] == "353" && \
got[11] == "171" && \
got[12] == "242" && \
got[13] == "240" && \
got[14] == "000" && \
got[15] == "000")
{
print "Cray CFP"
found = 1
exit
}
}
}
END {
if (! found)
print "unknown", saw
}
]])
|
