roundl: Simplify for platforms where 'long double' == 'double'.

* lib/roundl.c: Include <config.h>.
(roundl) [HAVE_SAME_LONG_DOUBLE_AS_DOUBLE]: New function.
* lib/round.c [!USE_LONG_DOUBLE]: Don't include <config.h> a second
time.
* m4/roundl.m4 (gl_FUNC_ROUNDL): Require gl_LONG_DOUBLE_VS_DOUBLE.
Determine ROUNDL_LIBM according to HAVE_SAME_LONG_DOUBLE_AS_DOUBLE.
* modules/roundl (Depends-on): Add round. Update conditions.

5 files changed, 65 insertions, 26 deletions

diff --git a/ChangeLog b/ChangeLog
index 64549f443d..a342bb0ac5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2011-10-09  Bruno Haible  <bruno@clisp.org>
 
+	roundl: Simplify for platforms where 'long double' == 'double'.
+	* lib/roundl.c: Include <config.h>.
+	(roundl) [HAVE_SAME_LONG_DOUBLE_AS_DOUBLE]: New function.
+	* lib/round.c [!USE_LONG_DOUBLE]: Don't include <config.h> a second
+	time.
+	* m4/roundl.m4 (gl_FUNC_ROUNDL): Require gl_LONG_DOUBLE_VS_DOUBLE.
+	Determine ROUNDL_LIBM according to HAVE_SAME_LONG_DOUBLE_AS_DOUBLE.
+	* modules/roundl (Depends-on): Add round. Update conditions.
+
+2011-10-09  Bruno Haible  <bruno@clisp.org>
+
 	truncl: Simplify for platforms where 'long double' == 'double'.
 	* lib/truncl.c: Include <config.h>.
 	(truncl) [HAVE_SAME_LONG_DOUBLE_AS_DOUBLE]: New function.
diff --git a/lib/round.c b/lib/round.c
index a1dbead444..a6c778e7a3 100644
--- a/lib/round.c
+++ b/lib/round.c
@@ -18,7 +18,9 @@
 /* Written by Ben Pfaff <blp@gnu.org>, 2007.
    Based heavily on code by Bruno Haible. */
 
-#include <config.h>
+#if ! defined USE_LONG_DOUBLE
+# include <config.h>
+#endif
 
 /* Specification.  */
 #include <math.h>
diff --git a/lib/roundl.c b/lib/roundl.c
index 28f3f6f5c8..9cf81db4c1 100644
--- a/lib/roundl.c
+++ b/lib/roundl.c
@@ -15,5 +15,22 @@
    with this program; if not, write to the Free Software Foundation,
    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#define USE_LONG_DOUBLE
-#include "round.c"
+#include <config.h>
+
+#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
+
+/* Specification.  */
+# include <math.h>
+
+long double
+roundl (long double x)
+{
+  return round (x);
+}
+
+#else
+
+# define USE_LONG_DOUBLE
+# include "round.c"
+
+#endif
diff --git a/m4/roundl.m4 b/m4/roundl.m4
index eece9d7cb3..fcabe9ee0a 100644
--- a/m4/roundl.m4
+++ b/m4/roundl.m4
@@ -1,4 +1,4 @@
-# roundl.m4 serial 12
+# roundl.m4 serial 13
 dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,8 +8,11 @@ AC_DEFUN([gl_FUNC_ROUNDL],
 [
   m4_divert_text([DEFAULTS], [gl_roundl_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+
   dnl Persuade glibc <math.h> to declare roundl().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   AC_CHECK_DECLS([roundl], , , [[#include <math.h>]])
   if test "$ac_cv_have_decl_roundl" = yes; then
     gl_CHECK_MATH_LIB([ROUNDL_LIBM], [x = roundl (x);])
@@ -61,30 +64,35 @@ int main (int argc, char *argv[])
   fi
   if test $HAVE_DECL_ROUNDL = 0 || test $REPLACE_ROUNDL = 1; then
     dnl Find libraries needed to link lib/roundl.c.
-    AC_CHECK_DECLS([ceill, floorl], , , [[#include <math.h>]])
-    if test "$ac_cv_have_decl_floorl" = yes \
-       && test "$ac_cv_have_decl_ceill" = yes; then
-      gl_FUNC_FLOORL_LIBS
-      gl_FUNC_CEILL_LIBS
-      if test "$FLOORL_LIBM" != '?' && test "$CEILL_LIBM" != '?'; then
-        AC_DEFINE([HAVE_FLOORL_AND_CEILL], [1],
-          [Define if the both the floorl() and ceill() functions exist.])
-        ROUNDL_LIBM=
-        dnl Append $FLOORL_LIBM to ROUNDL_LIBM, avoiding gratuitous duplicates.
-        case " $ROUNDL_LIBM " in
-          *" $FLOORL_LIBM "*) ;;
-          *) ROUNDL_LIBM="$ROUNDL_LIBM $FLOORL_LIBM" ;;
-        esac
-        dnl Append $CEILL_LIBM to ROUNDL_LIBM, avoiding gratuitous duplicates.
-        case " $ROUNDL_LIBM " in
-          *" $CEILL_LIBM "*) ;;
-          *) ROUNDL_LIBM="$ROUNDL_LIBM $CEILL_LIBM" ;;
-        esac
+    if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+      AC_REQUIRE([gl_FUNC_ROUND])
+      ROUNDL_LIBM="$ROUND_LIBM"
+    else
+      AC_CHECK_DECLS([ceill, floorl], , , [[#include <math.h>]])
+      if test "$ac_cv_have_decl_floorl" = yes \
+         && test "$ac_cv_have_decl_ceill" = yes; then
+        gl_FUNC_FLOORL_LIBS
+        gl_FUNC_CEILL_LIBS
+        if test "$FLOORL_LIBM" != '?' && test "$CEILL_LIBM" != '?'; then
+          AC_DEFINE([HAVE_FLOORL_AND_CEILL], [1],
+            [Define if the both the floorl() and ceill() functions exist.])
+          ROUNDL_LIBM=
+          dnl Append $FLOORL_LIBM to ROUNDL_LIBM, avoiding gratuitous duplicates.
+          case " $ROUNDL_LIBM " in
+            *" $FLOORL_LIBM "*) ;;
+            *) ROUNDL_LIBM="$ROUNDL_LIBM $FLOORL_LIBM" ;;
+          esac
+          dnl Append $CEILL_LIBM to ROUNDL_LIBM, avoiding gratuitous duplicates.
+          case " $ROUNDL_LIBM " in
+            *" $CEILL_LIBM "*) ;;
+            *) ROUNDL_LIBM="$ROUNDL_LIBM $CEILL_LIBM" ;;
+          esac
+        else
+          ROUNDL_LIBM=
+        fi
       else
         ROUNDL_LIBM=
       fi
-    else
-      ROUNDL_LIBM=
     fi
   fi
   AC_SUBST([ROUNDL_LIBM])
diff --git a/modules/roundl b/modules/roundl
index 91671f4411..3b5c962889 100644
--- a/modules/roundl
+++ b/modules/roundl
@@ -12,7 +12,8 @@ m4/ceill.m4
 Depends-on:
 math
 extensions
-float           [test $HAVE_DECL_ROUNDL = 0 || test $REPLACE_ROUNDL = 1]
+round           [{ test $HAVE_DECL_ROUNDL = 0 || test $REPLACE_ROUNDL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1]
+float           [{ test $HAVE_DECL_ROUNDL = 0 || test $REPLACE_ROUNDL = 1; } && test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 0]
 
 configure.ac:
 gl_FUNC_ROUNDL