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authorAndreas Rottmann <a.rottmann@gmx.at>2009-09-14 12:32:44 +0200
committerAndreas Rottmann <a.rottmann@gmx.at>2009-09-14 12:32:44 +0200
commitfa095a4504cbe668e4244547e2c141597bea4ecf (patch)
tree06135820a286ffec47804e75fbf8a147e92acd2e /gnulib-m4/isnanf.m4
Imported Upstream version 0.9.1upstream/0.9.1
Diffstat (limited to 'gnulib-m4/isnanf.m4')
-rw-r--r--gnulib-m4/isnanf.m4179
1 files changed, 179 insertions, 0 deletions
diff --git a/gnulib-m4/isnanf.m4 b/gnulib-m4/isnanf.m4
new file mode 100644
index 00000000..2ad8f945
--- /dev/null
+++ b/gnulib-m4/isnanf.m4
@@ -0,0 +1,179 @@
+# isnanf.m4 serial 10
+dnl Copyright (C) 2007-2009 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.
+
+dnl Check how to get or define isnanf().
+
+AC_DEFUN([gl_FUNC_ISNANF],
+[
+ AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ ISNANF_LIBM=
+ gl_HAVE_ISNANF_NO_LIBM
+ if test $gl_cv_func_isnanf_no_libm = no; then
+ gl_HAVE_ISNANF_IN_LIBM
+ if test $gl_cv_func_isnanf_in_libm = yes; then
+ ISNANF_LIBM=-lm
+ fi
+ fi
+ if test $gl_cv_func_isnanf_no_libm = yes \
+ || test $gl_cv_func_isnanf_in_libm = yes; then
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $ISNANF_LIBM"
+ gl_ISNANF_WORKS
+ LIBS="$save_LIBS"
+ case "$gl_cv_func_isnanf_works" in
+ *yes) gl_func_isnanf=yes ;;
+ *) gl_func_isnanf=no; ISNANF_LIBM= ;;
+ esac
+ else
+ gl_func_isnanf=no
+ fi
+ if test $gl_func_isnanf != yes; then
+ HAVE_ISNANF=0
+ gl_BUILD_ISNANF
+ fi
+ AC_SUBST([ISNANF_LIBM])
+])
+
+dnl Check how to get or define isnanf() without linking with libm.
+
+AC_DEFUN([gl_FUNC_ISNANF_NO_LIBM],
+[
+ gl_HAVE_ISNANF_NO_LIBM
+ if test $gl_cv_func_isnanf_no_libm = yes; then
+ gl_ISNANF_WORKS
+ fi
+ if test $gl_cv_func_isnanf_no_libm = yes \
+ && { case "$gl_cv_func_isnanf_works" in
+ *yes) true;;
+ *) false;;
+ esac
+ }; then
+ AC_DEFINE([HAVE_ISNANF_IN_LIBC], [1],
+ [Define if the isnan(float) function is available in libc.])
+ else
+ gl_BUILD_ISNANF
+ fi
+])
+
+dnl Pull in replacement isnanf definition. It does not need -lm.
+AC_DEFUN([gl_BUILD_ISNANF],
+[
+ AC_LIBOBJ([isnanf])
+ gl_FLOAT_EXPONENT_LOCATION
+])
+
+dnl Test whether isnanf() can be used without libm.
+AC_DEFUN([gl_HAVE_ISNANF_NO_LIBM],
+[
+ AC_CACHE_CHECK([whether isnan(float) can be used without linking with libm],
+ [gl_cv_func_isnanf_no_libm],
+ [
+ AC_TRY_LINK([#include <math.h>
+ #if __GNUC__ >= 4
+ # undef isnanf
+ # define isnanf(x) __builtin_isnanf ((float)(x))
+ #elif defined isnan
+ # undef isnanf
+ # define isnanf(x) isnan ((float)(x))
+ #endif
+ float x;],
+ [return isnanf (x);],
+ [gl_cv_func_isnanf_no_libm=yes],
+ [gl_cv_func_isnanf_no_libm=no])
+ ])
+])
+
+dnl Test whether isnanf() can be used with libm.
+AC_DEFUN([gl_HAVE_ISNANF_IN_LIBM],
+[
+ AC_CACHE_CHECK([whether isnan(float) can be used with libm],
+ [gl_cv_func_isnanf_in_libm],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS -lm"
+ AC_TRY_LINK([#include <math.h>
+ #if __GNUC__ >= 4
+ # undef isnanf
+ # define isnanf(x) __builtin_isnanf ((float)(x))
+ #elif defined isnan
+ # undef isnanf
+ # define isnanf(x) isnan ((float)(x))
+ #endif
+ float x;],
+ [return isnanf (x);],
+ [gl_cv_func_isnanf_in_libm=yes],
+ [gl_cv_func_isnanf_in_libm=no])
+ LIBS="$save_LIBS"
+ ])
+])
+
+dnl Test whether isnanf() rejects Infinity (this fails on Solaris 2.5.1),
+dnl recognizes a NaN (this fails on IRIX 6.5 with cc), and recognizes a NaN
+dnl with in-memory representation 0x7fbfffff (this fails on IRIX 6.5).
+AC_DEFUN([gl_ISNANF_WORKS],
+[
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_REQUIRE([gl_FLOAT_EXPONENT_LOCATION])
+ AC_CACHE_CHECK([whether isnan(float) works], [gl_cv_func_isnanf_works],
+ [
+ AC_TRY_RUN([
+#include <math.h>
+#if __GNUC__ >= 4
+# undef isnanf
+# define isnanf(x) __builtin_isnanf ((float)(x))
+#elif defined isnan
+# undef isnanf
+# define isnanf(x) isnan ((float)(x))
+#endif
+/* The Compaq (ex-DEC) C 6.4 compiler chokes on the expression 0.0 / 0.0. */
+#ifdef __DECC
+static float
+NaN ()
+{
+ static float zero = 0.0f;
+ return zero / zero;
+}
+#else
+# define NaN() (0.0f / 0.0f)
+#endif
+#define NWORDS \
+ ((sizeof (float) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+typedef union { unsigned int word[NWORDS]; float value; } memory_float;
+int main()
+{
+ memory_float m;
+
+ if (isnanf (1.0f / 0.0f))
+ return 1;
+
+ if (!isnanf (NaN ()))
+ return 1;
+
+#if defined FLT_EXPBIT0_WORD && defined FLT_EXPBIT0_BIT
+ /* The isnanf function should be immune against changes in the sign bit and
+ in the mantissa bits. The xor operation twiddles a bit that can only be
+ a sign bit or a mantissa bit. */
+ if (FLT_EXPBIT0_WORD == 0 && FLT_EXPBIT0_BIT > 0)
+ {
+ m.value = NaN ();
+ /* Set the bits below the exponent to 01111...111. */
+ m.word[0] &= -1U << FLT_EXPBIT0_BIT;
+ m.word[0] |= 1U << (FLT_EXPBIT0_BIT - 1) - 1;
+ if (!isnanf (m.value))
+ return 1;
+ }
+#endif
+
+ return 0;
+}], [gl_cv_func_isnanf_works=yes], [gl_cv_func_isnanf_works=no],
+ [case "$host_os" in
+ irix* | solaris*) gl_cv_func_isnanf_works="guessing no";;
+ *) gl_cv_func_isnanf_works="guessing yes";;
+ esac
+ ])
+ ])
+])