X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Flogl.m4;h=769cfe0d5fcb0b4a39693048dcb7de553f03bdc7;hb=bbfcd2f1a92c9bdbb8d7d7d0a8a8c6665c316747;hp=196dcbdaa118c82ed0ce4671d13e5b538db456ac;hpb=73e329f11142c2804e42825e1590041d68dbb6e9;p=gnulib.git

diff --git a/m4/logl.m4 b/m4/logl.m4
index 196dcbdaa..769cfe0d5 100644
--- a/m4/logl.m4
+++ b/m4/logl.m4
@@ -1,5 +1,5 @@
-# logl.m4 serial 1
-dnl Copyright (C) 2010 Free Software Foundation, Inc.
+# logl.m4 serial 9
+dnl Copyright (C) 2010-2013 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.
@@ -7,6 +7,8 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_LOGL],
 [
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
+  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+
   dnl Persuade glibc <math.h> to declare logl().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
 
@@ -14,12 +16,16 @@ AC_DEFUN([gl_FUNC_LOGL],
   AC_CACHE_CHECK([whether logl() can be used without linking with libm],
     [gl_cv_func_logl_no_libm],
     [
-      AC_TRY_LINK([#ifndef __NO_MATH_INLINES
-                   # define __NO_MATH_INLINES 1 /* for glibc */
-                   #endif
-                   #include <math.h>
-                   long double x;],
-                  [return logl (x) > 1;],
+      AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM(
+           [[#ifndef __NO_MATH_INLINES
+             # define __NO_MATH_INLINES 1 /* for glibc */
+             #endif
+             #include <math.h>
+             long double (*funcptr) (long double) = logl;
+             long double x;]],
+           [[return funcptr (x) > 1
+                    || logl (x) > 1;]])],
         [gl_cv_func_logl_no_libm=yes],
         [gl_cv_func_logl_no_libm=no])
     ])
@@ -29,12 +35,16 @@ AC_DEFUN([gl_FUNC_LOGL],
       [
         save_LIBS="$LIBS"
         LIBS="$LIBS -lm"
-        AC_TRY_LINK([#ifndef __NO_MATH_INLINES
-                     # define __NO_MATH_INLINES 1 /* for glibc */
-                     #endif
-                     #include <math.h>
-                     long double x;],
-                    [return logl (x) > 1;],
+        AC_LINK_IFELSE(
+          [AC_LANG_PROGRAM(
+             [[#ifndef __NO_MATH_INLINES
+               # define __NO_MATH_INLINES 1 /* for glibc */
+               #endif
+               #include <math.h>
+               long double (*funcptr) (long double) = logl;
+               long double x;]],
+             [[return funcptr (x) > 1
+                      || logl (x) > 1;]])],
           [gl_cv_func_logl_in_libm=yes],
           [gl_cv_func_logl_in_libm=no])
         LIBS="$save_LIBS"
@@ -46,16 +56,79 @@ AC_DEFUN([gl_FUNC_LOGL],
   if test $gl_cv_func_logl_no_libm = yes \
      || test $gl_cv_func_logl_in_libm = yes; then
     dnl Also check whether it's declared.
-    dnl MacOS X 10.3 has logl() in libc but doesn't declare it in <math.h>.
-    AC_CHECK_DECL([logl], , [HAVE_DECL_LOGL=0], [#include <math.h>])
+    dnl Mac OS X 10.3 has logl() in libc but doesn't declare it in <math.h>.
+    AC_CHECK_DECL([logl], , [HAVE_DECL_LOGL=0], [[#include <math.h>]])
+    save_LIBS="$LIBS"
+    LIBS="$LIBS $LOGL_LIBM"
+    gl_FUNC_LOGL_WORKS
+    LIBS="$save_LIBS"
+    case "$gl_cv_func_logl_works" in
+      *yes) ;;
+      *) REPLACE_LOGL=1 ;;
+    esac
   else
-    HAVE_DECL_LOGL=0
     HAVE_LOGL=0
-    AC_LIBOBJ([logl])
-    AC_REQUIRE([gl_FUNC_FREXPL])
-    AC_REQUIRE([gl_FUNC_ISNANL])
-    AC_REQUIRE([gl_FUNC_FLOORL])
-    LOGL_LIBM="$FREXPL_LIBM $ISNANL_LIBM $FLOORL_LIBM"
+    HAVE_DECL_LOGL=0
+  fi
+  if test $HAVE_LOGL = 0 || test $REPLACE_LOGL = 1; then
+    dnl Find libraries needed to link lib/logl.c.
+    if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+      AC_REQUIRE([gl_FUNC_LOG])
+      LOGL_LIBM="$LOG_LIBM"
+    else
+      if test $HAVE_LOGL = 0; then
+        AC_REQUIRE([gl_FUNC_FREXPL])
+        AC_REQUIRE([gl_FUNC_ISNANL])
+        AC_REQUIRE([gl_FUNC_FLOORL])
+        dnl Append $FREXPL_LIBM to LOGL_LIBM, avoiding gratuitous duplicates.
+        case " $LOGL_LIBM " in
+          *" $FREXPL_LIBM "*) ;;
+          *) LOGL_LIBM="$LOGL_LIBM $FREXPL_LIBM" ;;
+        esac
+        dnl Append $ISNANL_LIBM to LOGL_LIBM, avoiding gratuitous duplicates.
+        case " $LOGL_LIBM " in
+          *" $ISNANL_LIBM "*) ;;
+          *) LOGL_LIBM="$LOGL_LIBM $ISNANL_LIBM" ;;
+        esac
+        dnl Append $FLOORL_LIBM to LOGL_LIBM, avoiding gratuitous duplicates.
+        case " $LOGL_LIBM " in
+          *" $FLOORL_LIBM "*) ;;
+          *) LOGL_LIBM="$LOGL_LIBM $FLOORL_LIBM" ;;
+        esac
+      fi
+    fi
   fi
   AC_SUBST([LOGL_LIBM])
 ])
+
+dnl Test whether logl() works.
+dnl On OSF/1 5.1, logl(-0.0L) is NaN.
+AC_DEFUN([gl_FUNC_LOGL_WORKS],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether logl works], [gl_cv_func_logl_works],
+    [
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+#include <math.h>
+volatile long double x;
+long double y;
+int main ()
+{
+  x = -0.0L;
+  y = logl (x);
+  if (!(y + y == y))
+    return 1;
+  return 0;
+}
+]])],
+        [gl_cv_func_logl_works=yes],
+        [gl_cv_func_logl_works=no],
+        [case "$host_os" in
+           osf*) gl_cv_func_logl_works="guessing no";;
+           *)    gl_cv_func_logl_works="guessing yes";;
+         esac
+        ])
+    ])
+])