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-rw-r--r--gnulib-m4/frexp.m4146
1 files changed, 146 insertions, 0 deletions
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 <math.h>
+ 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="$LIBS -lm"
+ AC_TRY_LINK([#include <math.h>
+ double x;],
+ [int e; return frexp (x, &e) > 0;],
+ [gl_cv_func_frexp_in_libm=yes],
+ [gl_cv_func_frexp_in_libm=no])
+ LIBS="$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 <math.h>
+ 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 $gl_func_frexp_no_libm = yes; then
+ AC_DEFINE([HAVE_FREXP_IN_LIBC], [1],
+ [Define if the frexp() function is available in libc.])
+ else
+ AC_LIBOBJ([frexp])
+ fi
+])
+
+dnl Test whether frexp() works also on denormalized numbers (this fails e.g. on
+dnl NetBSD 3.0), on infinite numbers (this fails e.g. on IRIX 6.5 and mingw),
+dnl and on negative zero (this fails e.g. on NetBSD 4.99).
+AC_DEFUN([gl_FUNC_FREXP_WORKS],
+[
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works],
+ [
+ AC_TRY_RUN([
+#include <float.h>
+#include <math.h>
+#include <string.h>
+int main()
+{
+ int i;
+ volatile double x;
+/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
+ So we use -zero instead. */
+ double zero = 0.0;
+ /* Test on denormalized numbers. */
+ for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5)
+ ;
+ if (x > 0.0)
+ {
+ int exp;
+ double y = frexp (x, &exp);
+ /* On machines with IEEE754 arithmetic: x = 1.11254e-308, exp = -1022.
+ On NetBSD: y = 0.75. Correct: y = 0.5. */
+ if (y != 0.5)
+ return 1;
+ }
+ /* Test on infinite numbers. */
+ x = 1.0 / 0.0;
+ {
+ int exp;
+ double y = frexp (x, &exp);
+ if (y != x)
+ return 1;
+ }
+ /* Test on negative zero. */
+ x = -zero;
+ {
+ int exp;
+ double y = frexp (x, &exp);
+ if (memcmp (&y, &x, sizeof x))
+ return 1;
+ }
+ return 0;
+}], [gl_cv_func_frexp_works=yes], [gl_cv_func_frexp_works=no],
+ [case "$host_os" in
+ netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";;
+ *) gl_cv_func_frexp_works="guessing yes";;
+ esac
+ ])
+ ])
+])