NEWS.stable: log cherry-pick [e446f25]->[c092018] relocatable-shell: Update suggested...

[gnulib.git] / m4 / floorl.m4

diff --git a/m4/floorl.m4 b/m4/floorl.m4
index f21285d..3bf471b 100644 (file)
--- a/m4/floorl.m4
+++ b/m4/floorl.m4
@@ -1,5 +1,5 @@
-# floorl.m4 serial 8
-dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+# floorl.m4 serial 11
+dnl Copyright (C) 2007, 2009-2014 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.
@@ -7,10 +7,13 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_FLOORL],
 [
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+
   dnl Persuade glibc <math.h> to declare floorl().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether floorl() is declared.
-  AC_CHECK_DECLS([floorl], , , [#include <math.h>])
+  AC_CHECK_DECLS([floorl], , , [[#include <math.h>]])
   if test "$ac_cv_have_decl_floorl" = yes; then
     dnl Test whether floorl() can be used without libm.
     gl_FUNC_FLOORL_LIBS
@@ -23,8 +26,13 @@ AC_DEFUN([gl_FUNC_FLOORL],
     HAVE_DECL_FLOORL=0
   fi
   if test $HAVE_DECL_FLOORL = 0 || test $REPLACE_FLOORL = 1; then
-    dnl No libraries are needed to link lib/floorl.c.
-    FLOORL_LIBM=
+    dnl Find libraries needed to link lib/floorl.c.
+    if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+      AC_REQUIRE([gl_FUNC_FLOOR])
+      FLOORL_LIBM="$FLOOR_LIBM"
+    else
+      FLOORL_LIBM=
+    fi
   fi
   AC_SUBST([FLOORL_LIBM])
 ])
@@ -41,8 +49,9 @@ AC_DEFUN([gl_FUNC_FLOORL_LIBS],
            # define __NO_MATH_INLINES 1 /* for glibc */
            #endif
            #include <math.h>
+           long double (*funcptr) (long double) = floorl;
            long double x;]],
-         [[x = floorl(x);]])],
+         [[x = funcptr (x) + floorl(x);]])],
       [gl_cv_func_floorl_libm=])
     if test "$gl_cv_func_floorl_libm" = "?"; then
       save_LIBS="$LIBS"
@@ -53,8 +62,9 @@ AC_DEFUN([gl_FUNC_FLOORL_LIBS],
              # define __NO_MATH_INLINES 1 /* for glibc */
              #endif
              #include <math.h>
+             long double (*funcptr) (long double) = floorl;
              long double x;]],
-           [[x = floorl(x);]])],
+           [[x = funcptr (x) + floorl(x);]])],
         [gl_cv_func_floorl_libm="-lm"])
       LIBS="$save_LIBS"
     fi