From fa095a4504cbe668e4244547e2c141597bea4ecf Mon Sep 17 00:00:00 2001 From: Andreas Rottmann Date: Mon, 14 Sep 2009 12:32:44 +0200 Subject: Imported Upstream version 0.9.1 --- gnulib-m4/frexp.m4 | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 gnulib-m4/frexp.m4 (limited to 'gnulib-m4/frexp.m4') diff --git a/gnulib-m4/frexp.m4 b/gnulib-m4/frexp.m4 new file mode 100644 index 00000000..6c911121 --- /dev/null +++ b/gnulib-m4/frexp.m4 @@ -0,0 +1,146 @@ +# frexp.m4 serial 7 +dnl Copyright (C) 2007, 2008, 2009 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. + +AC_DEFUN([gl_FUNC_FREXP], +[ + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + FREXP_LIBM= + AC_CACHE_CHECK([whether frexp() can be used without linking with libm], + [gl_cv_func_frexp_no_libm], + [ + AC_TRY_LINK([#include + double x;], + [int e; return frexp (x, &e) > 0;], + [gl_cv_func_frexp_no_libm=yes], + [gl_cv_func_frexp_no_libm=no]) + ]) + if test $gl_cv_func_frexp_no_libm = no; then + AC_CACHE_CHECK([whether frexp() can be used with libm], + [gl_cv_func_frexp_in_libm], + [ + save_LIBS="$LIBS" + LIBS="$LIBS -lm" + AC_TRY_LINK([#include + double x;], + [int e; return frexp (x, &e) > 0;], + [gl_cv_func_frexp_in_libm=yes], + [gl_cv_func_frexp_in_libm=no]) + LIBS="$save_LIBS" + ]) + if test $gl_cv_func_frexp_in_libm = yes; then + FREXP_LIBM=-lm + fi + fi + if test $gl_cv_func_frexp_no_libm = yes \ + || test $gl_cv_func_frexp_in_libm = yes; then + save_LIBS="$LIBS" + LIBS="$LIBS $FREXP_LIBM" + gl_FUNC_FREXP_WORKS + LIBS="$save_LIBS" + case "$gl_cv_func_frexp_works" in + *yes) gl_func_frexp=yes ;; + *) gl_func_frexp=no; REPLACE_FREXP=1; FREXP_LIBM= ;; + esac + else + gl_func_frexp=no + fi + if test $gl_func_frexp = yes; then + AC_DEFINE([HAVE_FREXP], [1], + [Define if the frexp() function is available and works.]) + else + AC_LIBOBJ([frexp]) + fi + AC_SUBST([FREXP_LIBM]) +]) + +AC_DEFUN([gl_FUNC_FREXP_NO_LIBM], +[ + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + AC_CACHE_CHECK([whether frexp() can be used without linking with libm], + [gl_cv_func_frexp_no_libm], + [ + AC_TRY_LINK([#include + double x;], + [int e; return frexp (x, &e) > 0;], + [gl_cv_func_frexp_no_libm=yes], + [gl_cv_func_frexp_no_libm=no]) + ]) + if test $gl_cv_func_frexp_no_libm = yes; then + gl_FUNC_FREXP_WORKS + case "$gl_cv_func_frexp_works" in + *yes) gl_func_frexp_no_libm=yes ;; + *) gl_func_frexp_no_libm=no; REPLACE_FREXP=1 ;; + esac + else + gl_func_frexp_no_libm=no + dnl Set REPLACE_FREXP here because the system may have frexp in libm. + REPLACE_FREXP=1 + fi + if test $gl_func_frexp_no_libm = yes; then + AC_DEFINE([HAVE_FREXP_IN_LIBC], [1], + [Define if the frexp() function is available in libc.]) + else + AC_LIBOBJ([frexp]) + fi +]) + +dnl Test whether frexp() works also on denormalized numbers (this fails e.g. on +dnl NetBSD 3.0), on infinite numbers (this fails e.g. on IRIX 6.5 and mingw), +dnl and on negative zero (this fails e.g. on NetBSD 4.99). +AC_DEFUN([gl_FUNC_FREXP_WORKS], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works], + [ + AC_TRY_RUN([ +#include +#include +#include +int main() +{ + int i; + volatile double x; +/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0. + So we use -zero instead. */ + double zero = 0.0; + /* Test on denormalized numbers. */ + for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5) + ; + if (x > 0.0) + { + int exp; + double y = frexp (x, &exp); + /* On machines with IEEE754 arithmetic: x = 1.11254e-308, exp = -1022. + On NetBSD: y = 0.75. Correct: y = 0.5. */ + if (y != 0.5) + return 1; + } + /* Test on infinite numbers. */ + x = 1.0 / 0.0; + { + int exp; + double y = frexp (x, &exp); + if (y != x) + return 1; + } + /* Test on negative zero. */ + x = -zero; + { + int exp; + double y = frexp (x, &exp); + if (memcmp (&y, &x, sizeof x)) + return 1; + } + return 0; +}], [gl_cv_func_frexp_works=yes], [gl_cv_func_frexp_works=no], + [case "$host_os" in + netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";; + *) gl_cv_func_frexp_works="guessing yes";; + esac + ]) + ]) +]) -- cgit v1.2.3