Note that GCC 4.0 will optimize ceil (constant), we therefore
have to make the argument non-constant.

================================================================================
Index: configure.ac
===================================================================
--- configure.ac.orig	2009-02-09 10:58:53.000000000 +0100
+++ configure.ac	2010-09-08 16:10:06.434722846 +0200
@@ -108,6 +108,25 @@ fi
 AC_CHECK_FUNCS(vsyslog syslog)
 AC_FUNC_ALLOCA
 
+AC_MSG_CHECKING(for ceil)
+AC_TRY_LINK([#define __NO_MATH_INLINES 1
+             double d;],
+	    [d = ceil(1.0*d);],
+	    SYNLDFLAGS=""
+	    AC_MSG_RESULT(yes),
+	    SYNLDFLAGS=-lm
+	    AC_MSG_RESULT(no))
+
+if test "$SYNLDFLAGS" = "-lm" ; then
+    SAVE_LIBS="$LIBS"
+    AC_CHECK_LIB(m,
+                 ceil,
+		 ,
+		 echo "libmath.so is needed due the ceil function"
+		 exit 1)
+    LIBS="$SAVE_LIBS"
+fi
+
 case $with_curses in
 No|no|N|n) SHARED_LIBS=-lc ;;
 *)
@@ -138,6 +157,7 @@ AC_SUBST(ELISP)
 AC_SUBST(SHLIB)
 AC_SUBST(PICFLAGS)
 AC_SUBST(SOLDFLAGS)
+AC_SUBST(SYNLDFLAGS)
 AC_SUBST(CURSES_OBJS)
 AC_SUBST(SHARED_LIBS)
 AC_SUBST(lispdir)
Index: src/Makefile.in
===================================================================
--- src/Makefile.in.orig	2010-09-08 16:06:46.812997967 +0200
+++ src/Makefile.in	2010-09-08 16:09:40.464506680 +0200
@@ -82,7 +82,7 @@ prog/%:	prog/%.o
 all:	gpm lib/libgpm.so.@abi_lev@ lib/libgpm.a $(PROG)
 
 gpm:	$(GOBJ)
-	$(CC) @LDFLAGS@ $(LDFLAGS) -o $@ $(GOBJ) @LIBS@ $(LIBS) -lm
+	$(CC) @LDFLAGS@ @SYNLDFLAGS@ -o $@ $(GOBJ) @LIBS@ $(LIBS) -lm
 
 # construct dependings of sourcefiles and link sourcefiles
 $(DEPFILE) dep: prog/gpm-root.c
@@ -164,7 +164,8 @@ lib/libgpm.a:	$(LOBJ)
 
 lib/libgpm.so.@abi_full@:	$(PICS)
 	$(CC) @SOLDFLAGS@libgpm.so.@abi_lev@ \
-	@LDFLAGS@ $(LDFLAGS) -o lib/libgpm.so.@abi_full@ $^ @LIBS@ @SHARED_LIBS@ $(LIBS)	
+	@LDFLAGS@ $(LDFLAGS) -o lib/libgpm.so.@abi_full@ $^ @LIBS@ @SHARED_LIBS@ @SYNLDFLAGS@ $(LIBS)
+
 lib/libgpm.so.@abi_lev@:	lib/libgpm.so.@abi_full@
 	$(LN_S) -f libgpm.so.@abi_full@ lib/libgpm.so.@abi_lev@
 # unneeded, isn't it?