X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fisnan.m4;h=ababb254b4c78301faed999b78ac83e9843bb5df;hb=43593319b31e6b0175b8eec4433bac744959822d;hp=f146601cd63b00f4721c92e34a411429cb870040;hpb=7080851f5a8270aee50e8545d28c48c6c75decc1;p=gnulib.git

diff --git a/m4/isnan.m4 b/m4/isnan.m4
index f146601cd..ababb254b 100644
--- a/m4/isnan.m4
+++ b/m4/isnan.m4
@@ -1,5 +1,5 @@
-# isnan.m4 serial 1
-dnl Copyright (C) 2007-2008 Free Software Foundation, Inc.
+# isnan.m4 serial 5
+dnl Copyright (C) 2007-2013 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.
@@ -11,9 +11,6 @@ AC_DEFUN([gl_ISNAN],
   AC_REQUIRE([gl_FUNC_ISNAND])
   AC_REQUIRE([gl_FUNC_ISNANL])
 
-  ISNAN_LIBM="$ISNANF_LIBM $ISNAND_LIBM $ISNANL_LIBM"
-  AC_SUBST([ISNAN_LIBM])
-
   # If we replaced any of the underlying isnan* functions, replace
   # the isnan macro; it undoubtedly suffers from the same flaws.
   AC_MSG_CHECKING([whether isnan macro works])
@@ -21,12 +18,27 @@ AC_DEFUN([gl_ISNAN],
      && test $gl_func_isnand = yes \
      && test $gl_func_isnanl = yes; then
     AC_MSG_RESULT([yes])
+    ISNAN_LIBM=
+    dnl Append $ISNANF_LIBM to ISNAN_LIBM, avoiding gratuitous duplicates.
+    case " $ISNAN_LIBM " in
+      *" $ISNANF_LIBM "*) ;;
+      *) ISNAN_LIBM="$ISNAN_LIBM $ISNANF_LIBM" ;;
+    esac
+    dnl Append $ISNAND_LIBM to ISNAN_LIBM, avoiding gratuitous duplicates.
+    case " $ISNAN_LIBM " in
+      *" $ISNAND_LIBM "*) ;;
+      *) ISNAN_LIBM="$ISNAN_LIBM $ISNAND_LIBM" ;;
+    esac
+    dnl Append $ISNANL_LIBM to ISNAN_LIBM, avoiding gratuitous duplicates.
+    case " $ISNAN_LIBM " in
+      *" $ISNANL_LIBM "*) ;;
+      *) ISNAN_LIBM="$ISNAN_LIBM $ISNANL_LIBM" ;;
+    esac
   else
-    # Make sure the rpl_isnan[fdl] functions get built.
-    gl_BUILD_ISNANF
-    gl_BUILD_ISNAND
-    gl_BUILD_ISNANL
-    REPLACE_ISNAN=1
     AC_MSG_RESULT([no])
+    dnl REPLACE_ISNAN=1 also makes sure the rpl_isnan[fdl] functions get built.
+    REPLACE_ISNAN=1
+    ISNAN_LIBM=
   fi
+  AC_SUBST([ISNAN_LIBM])
 ])