Merge commit 'a39d4083cab589d7cd6a13e8a4b8db8875261d75'

[gnulib.git] / m4 / logl.m4

diff --git a/m4/logl.m4 b/m4/logl.m4
index dfc301a..12f4a70 100644 (file)
--- a/m4/logl.m4
+++ b/m4/logl.m4
@@ -1,5 +1,5 @@
-# logl.m4 serial 4
-dnl Copyright (C) 2010-2011 Free Software Foundation, Inc.
+# logl.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.
@@ -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])
 
@@ -20,8 +22,10 @@ AC_DEFUN([gl_FUNC_LOGL],
              # define __NO_MATH_INLINES 1 /* for glibc */
              #endif
              #include <math.h>
+             long double (*funcptr) (long double) = logl;
              long double x;]],
-           [[return logl (x) > 1;]])],
+           [[return funcptr (x) > 1
+                    || logl (x) > 1;]])],
         [gl_cv_func_logl_no_libm=yes],
         [gl_cv_func_logl_no_libm=no])
     ])
@@ -37,8 +41,10 @@ AC_DEFUN([gl_FUNC_LOGL],
                # define __NO_MATH_INLINES 1 /* for glibc */
                #endif
                #include <math.h>
+               long double (*funcptr) (long double) = logl;
                long double x;]],
-             [[return logl (x) > 1;]])],
+             [[return funcptr (x) > 1
+                      || logl (x) > 1;]])],
           [gl_cv_func_logl_in_libm=yes],
           [gl_cv_func_logl_in_libm=no])
         LIBS="$save_LIBS"
@@ -50,30 +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
+    HAVE_DECL_LOGL=0
+  fi
+  if test $HAVE_LOGL = 0 || test $REPLACE_LOGL = 1; then
     dnl Find libraries needed to link lib/logl.c.
-    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
+    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
+        ])
+    ])
+])