-# sqrtl.m4 serial 3
-dnl Copyright (C) 2010-2011 Free Software Foundation, Inc.
+# sqrtl.m4 serial 9
+dnl Copyright (C) 2010-2014 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_SQRTL],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+
dnl Persuade glibc <math.h> to declare sqrtl().
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
+ long double (*funcptr) (long double) = sqrtl;
long double x;]],
- [[return sqrtl (x) > 0.4;]])],
+ [[return funcptr (x) > 0.4
+ || sqrtl (x) > 0.4;]])],
[gl_cv_func_sqrtl_no_libm=yes],
[gl_cv_func_sqrtl_no_libm=no])
])
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
+ long double (*funcptr) (long double) = sqrtl;
long double x;]],
- [[return sqrtl (x) > 0.4;]])],
+ [[return funcptr (x) > 0.4
+ || sqrtl (x) > 0.4;]])],
[gl_cv_func_sqrtl_in_libm=yes],
[gl_cv_func_sqrtl_in_libm=no])
LIBS="$save_LIBS"
if test $gl_cv_func_sqrtl_no_libm = yes \
|| test $gl_cv_func_sqrtl_in_libm = yes; then
dnl Also check whether it's declared.
- dnl MacOS X 10.3 has sqrtl() in libc but doesn't declare it in <math.h>.
- AC_CHECK_DECL([sqrtl], , [HAVE_DECL_SQRTL=0], [#include <math.h>])
+ dnl Mac OS X 10.3 has sqrtl() in libc but doesn't declare it in <math.h>.
+ AC_CHECK_DECL([sqrtl], , [HAVE_DECL_SQRTL=0], [[#include <math.h>]])
+
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $SQRTL_LIBM"
+ gl_FUNC_SQRTL_WORKS
+ LIBS="$save_LIBS"
+ case "$gl_cv_func_sqrtl_works" in
+ *yes) ;;
+ *) REPLACE_SQRTL=1 ;;
+ esac
else
HAVE_DECL_SQRTL=0
HAVE_SQRTL=0
- AC_LIBOBJ([sqrtl])
- AC_REQUIRE([gl_FUNC_ISNANL])
- AC_REQUIRE([gl_FUNC_FREXPL])
- AC_REQUIRE([gl_FUNC_LDEXPL])
- AC_REQUIRE([gl_FUNC_SQRT])
- dnl Append $ISNANL_LIBM to SQRTL_LIBM, avoiding gratuitous duplicates.
- case " $SQRTL_LIBM " in
- *" $ISNANL_LIBM "*) ;;
- *) SQRTL_LIBM="$SQRTL_LIBM $ISNANL_LIBM" ;;
- esac
- dnl Append $FREXPL_LIBM to SQRTL_LIBM, avoiding gratuitous duplicates.
- case " $SQRTL_LIBM " in
- *" $FREXPL_LIBM "*) ;;
- *) SQRTL_LIBM="$SQRTL_LIBM $FREXPL_LIBM" ;;
- esac
- dnl Append $LDEXPL_LIBM to SQRTL_LIBM, avoiding gratuitous duplicates.
- case " $SQRTL_LIBM " in
- *" $LDEXPL_LIBM "*) ;;
- *) SQRTL_LIBM="$SQRTL_LIBM $LDEXPL_LIBM" ;;
- esac
- dnl Append $SQRT_LIBM to SQRTL_LIBM, avoiding gratuitous duplicates.
- case " $SQRTL_LIBM " in
- *" $SQRT_LIBM "*) ;;
- *) SQRTL_LIBM="$SQRTL_LIBM $SQRT_LIBM" ;;
- esac
+ fi
+ if test $HAVE_SQRTL = 0 || test $REPLACE_SQRTL = 1; then
+ dnl Find libraries needed to link lib/sqrtl.c.
+ if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+ AC_REQUIRE([gl_FUNC_SQRT])
+ SQRTL_LIBM="$SQRT_LIBM"
+ else
+ AC_REQUIRE([gl_FUNC_ISNANL])
+ AC_REQUIRE([gl_FUNC_FREXPL])
+ AC_REQUIRE([gl_FUNC_LDEXPL])
+ AC_REQUIRE([gl_FUNC_SQRT])
+ dnl Append $ISNANL_LIBM to SQRTL_LIBM, avoiding gratuitous duplicates.
+ case " $SQRTL_LIBM " in
+ *" $ISNANL_LIBM "*) ;;
+ *) SQRTL_LIBM="$SQRTL_LIBM $ISNANL_LIBM" ;;
+ esac
+ dnl Append $FREXPL_LIBM to SQRTL_LIBM, avoiding gratuitous duplicates.
+ case " $SQRTL_LIBM " in
+ *" $FREXPL_LIBM "*) ;;
+ *) SQRTL_LIBM="$SQRTL_LIBM $FREXPL_LIBM" ;;
+ esac
+ dnl Append $LDEXPL_LIBM to SQRTL_LIBM, avoiding gratuitous duplicates.
+ case " $SQRTL_LIBM " in
+ *" $LDEXPL_LIBM "*) ;;
+ *) SQRTL_LIBM="$SQRTL_LIBM $LDEXPL_LIBM" ;;
+ esac
+ dnl Append $SQRT_LIBM to SQRTL_LIBM, avoiding gratuitous duplicates.
+ case " $SQRTL_LIBM " in
+ *" $SQRT_LIBM "*) ;;
+ *) SQRTL_LIBM="$SQRTL_LIBM $SQRT_LIBM" ;;
+ esac
+ fi
fi
AC_SUBST([SQRTL_LIBM])
])
+
+dnl Test whether sqrtl() works.
+dnl On OpenBSD 5.1/SPARC, sqrtl(8.1974099812331540680810141969554806865L) has
+dnl rounding errors that eat up the last 8 to 9 decimal digits.
+AC_DEFUN([gl_FUNC_SQRTL_WORKS],
+[
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether sqrtl works], [gl_cv_func_sqrtl_works],
+ [
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <float.h>
+#include <math.h>
+#ifndef sqrtl /* for AIX */
+extern
+#ifdef __cplusplus
+"C"
+#endif
+long double sqrtl (long double);
+#endif
+static long double
+my_ldexpl (long double x, int d)
+{
+ for (; d > 0; d--)
+ x *= 2.0L;
+ for (; d < 0; d++)
+ x *= 0.5L;
+ return x;
+}
+volatile long double x;
+volatile long double y;
+long double z;
+int main ()
+{
+ x = 8.1974099812331540680810141969554806865L;
+ y = sqrtl (x);
+ z = y * y - x;
+ z = my_ldexpl (z, LDBL_MANT_DIG);
+ if (z < 0)
+ z = - z;
+ if (z > 100.0L)
+ return 1;
+ return 0;
+}
+]])],
+ [gl_cv_func_sqrtl_works=yes],
+ [gl_cv_func_sqrtl_works=no],
+ [case "$host_os" in
+ openbsd*) gl_cv_func_sqrtl_works="guessing no";;
+ *) gl_cv_func_sqrtl_works="guessing yes";;
+ esac
+ ])
+ ])
+])