-# logl.m4 serial 10
+# logl.m4 serial 11
dnl Copyright (C) 2010-2019 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 Test whether logl() works.
dnl On OSF/1 5.1, logl(-0.0L) is NaN.
+dnl On NetBSD 8.0, the result is accurate to only 16 digits.
AC_DEFUN([gl_FUNC_LOGL_WORKS],
[
AC_REQUIRE([AC_PROG_CC])
[
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <float.h>
#include <math.h>
-volatile long double x;
-long double y;
-int main ()
+/* Override the values of <float.h>, like done in float.in.h. */
+#if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__)
+# undef LDBL_MANT_DIG
+# define LDBL_MANT_DIG 64
+# undef LDBL_MIN_EXP
+# define LDBL_MIN_EXP (-16381)
+# undef LDBL_MAX_EXP
+# define LDBL_MAX_EXP 16384
+#endif
+#if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__)
+# undef LDBL_MANT_DIG
+# define LDBL_MANT_DIG 64
+# undef LDBL_MIN_EXP
+# define LDBL_MIN_EXP (-16381)
+# undef LDBL_MAX_EXP
+# define LDBL_MAX_EXP 16384
+#endif
+#if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__
+# undef LDBL_MIN_EXP
+# define LDBL_MIN_EXP DBL_MIN_EXP
+#endif
+#if defined __sgi && (LDBL_MANT_DIG >= 106)
+# undef LDBL_MANT_DIG
+# define LDBL_MANT_DIG 106
+# if defined __GNUC__
+# undef LDBL_MIN_EXP
+# define LDBL_MIN_EXP DBL_MIN_EXP
+# endif
+#endif
+#undef logl
+extern
+#ifdef __cplusplus
+"C"
+#endif
+long double logl (long double);
+static long double dummy (long double x) { return 0; }
+volatile long double gx;
+long double gy;
+int main (int argc, char *argv[])
{
- x = -0.0L;
- y = logl (x);
- if (!(y + y == y))
- return 1;
- return 0;
+ long double (* volatile my_logl) (long double) = argc ? logl : dummy;
+ int result = 0;
+ /* This test fails on OSF/1 5.1. */
+ {
+ gx = -0.0L;
+ gy = logl (gx);
+ if (!(gy + gy == gy))
+ result |= 1;
+ }
+ /* This test fails on NetBSD 8.0. */
+ {
+ const long double TWO_LDBL_MANT_DIG = /* 2^LDBL_MANT_DIG */
+ (long double) (1U << ((LDBL_MANT_DIG - 1) / 5))
+ * (long double) (1U << ((LDBL_MANT_DIG - 1 + 1) / 5))
+ * (long double) (1U << ((LDBL_MANT_DIG - 1 + 2) / 5))
+ * (long double) (1U << ((LDBL_MANT_DIG - 1 + 3) / 5))
+ * (long double) (1U << ((LDBL_MANT_DIG - 1 + 4) / 5));
+ long double x = 16.981137113807045L;
+ long double err = (my_logl (x) + my_logl (1.0L / x)) * TWO_LDBL_MANT_DIG;
+ if (!(err >= -100.0L && err <= 100.0L))
+ result |= 2;
+ }
+
+ return result;
}
]])],
[gl_cv_func_logl_works=yes],
[gl_cv_func_logl_works=no],
[case "$host_os" in
- osf*) gl_cv_func_logl_works="guessing no" ;;
- # Guess yes on native Windows.
- mingw*) gl_cv_func_logl_works="guessing yes" ;;
- *) gl_cv_func_logl_works="guessing yes" ;;
+ # Guess yes on glibc systems.
+ *-gnu* | gnu*) gl_cv_func_logl_works="guessing yes" ;;
+ # Guess yes on native Windows.
+ mingw*) gl_cv_func_logl_works="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_logl_works="guessing no" ;;
esac
])
])