--- gforth/configure.in	2002/10/04 19:17:05	1.87
+++ gforth/configure.in	2002/12/23 22:14:05	1.91
@@ -36,7 +36,7 @@ AC_ARG_ENABLE(force-reg,
 			  the machine.h file. This can cause a good speedup,
 			  but also incorrect code with some gcc versions on
 			  some processors (default disabled).],
-AC_DEFINE(FORCE_REG))
+AC_DEFINE(FORCE_REG,,[Define if you want to use explicit register declarations for better performance or for more convenient CODE words (does not work with all GCC versions on all machines)]))
 
 AC_ARG_WITH(debug,
 [  --with-debug     specifies option -g to compile with debug info (default)
@@ -117,7 +117,7 @@ if test "$ac_cv_int_type_cell" != int; t
 	echo "Since you don't have a proper C on this machine, that's one more reason"
 	echo "to use Forth;-)"
 fi
-AC_DEFINE_UNQUOTED(CELL_TYPE,$ac_cv_int_type_cell)
+AC_DEFINE_UNQUOTED(CELL_TYPE,$ac_cv_int_type_cell,[an integer type that is as long as a pointer])
 
 ac_cv_int_type_double_cell=none
 case `expr 2 '*' "$ac_cv_sizeof_char_p"` in
@@ -140,9 +140,9 @@ if test "$ac_cv_int_type_double_cell" =
 	echo 'long longs for your machine (the GCC manual states that they \"are twice as'
 	echo "long as \`long int\'\")."
 	AC_LIBOBJ(dblsub)
-	AC_DEFINE(BUGGY_LONG_LONG)
+	AC_DEFINE(BUGGY_LONG_LONG,,[define this if there is no working DOUBLE_CELL_TYPE on your machine])
 else
-  AC_DEFINE_UNQUOTED(DOUBLE_CELL_TYPE,$ac_cv_int_type_double_cell)
+  AC_DEFINE_UNQUOTED(DOUBLE_CELL_TYPE,$ac_cv_int_type_double_cell,[an integer type that is twice as long as a pointer])
 fi
 
 AC_MSG_CHECKING([whether the linker accepts -export-dynamic])
@@ -205,7 +205,7 @@ case "$host_cpu" in
 		AC_MSG_RESULT($ac_link_mips_t)
 		fixme #dynamically generated code should be in the same 256MB
 		# region as the text segment; no indirect threading necessary
-		test $ac_link_mips_t = yes||(echo cannot link text and data into same 256M region, using indirect threading; AC_DEFINE(INDIRECT_THREADED))
+		test $ac_link_mips_t = yes||(echo cannot link text and data into same 256M region, using indirect threading; AC_DEFINE(INDIRECT_THREADED,,[Define if you want to force an indirect threaded code implementation]))
 		AC_MSG_CHECKING([whether the linker accepts -D])
 		OLDLDFLAGS=$LDFLAGS
 		LDFLAGS="$LDFLAGS -Xlinker -D -Xlinker 10400000"
@@ -233,6 +233,12 @@ esac
 AC_SUBST(host)
 AC_SUBST(ENGINE_FLAGS)
 
+# Try if GCC understands -fno-cross-jump
+
+CFLAGS_1="$CFLAGS"
+CFLAGS="$CFLAGS -fno-cross-jump"
+AC_TRY_COMPILE(,,,CFLAGS="$CFLAGS_1")
+
 AC_CHECK_PROG(asm_fs,asm.fs,arch/$machine/asm.fs,,$srcdir/arch/$machine)
 AC_SUBST(asm_fs)
 
@@ -242,12 +248,16 @@ AC_SUBST(disasm_fs)
 case "$host_os" in
 	*win32)
 		EXE=".exe"
+		DIRSEP="\\"
 		;;
 	*)
 		EXE=""
+		DIRSEP="/"
 		;;
 esac
 AC_SUBST(EXE)
+AC_SUBST(DIRSEP)
+AC_DEFINE_UNQUOTED(DIRSEP,'$DIRSEP',[a directory separator character])
 
 dnl Now a little support for DOS/DJGCC
 AC_SUBST(GFORTH_EXE)
@@ -261,14 +271,14 @@ GFORTHDITC_EXE=""
 
 PATHSEP=":"
 AC_SUBST(PATHSEP)
-AC_DEFINE_UNQUOTED(PATHSEP,'$PATHSEP')
+AC_DEFINE_UNQUOTED(PATHSEP,'$PATHSEP',[a path separator character])
 
 AC_SUBST(FORTHSIZES)
 
 if test "$PEEPHOLE" = "yes"
 then
    PEEPHOLEFLAG="true"
-   AC_DEFINE(HAS_PEEPHOLE)
+   AC_DEFINE(HAS_PEEPHOLE,,[Define if you want to use peephole optimization])
 else
    PEEPHOLEFLAG="false"
 fi
@@ -297,6 +307,33 @@ else
   KERNEL="kernl16l.fi kernl16b.fi kernl32l.fi kernl32b.fi kernl64l.fi kernl64b.fi"
 fi
 
+#check how to do asm(".skip 16")
+for i in ".skip 16" ".block 16" ".org .+16" ".=.+16" ".space 16"
+do
+	AC_MSG_CHECKING([whether asm("$i") skips 16 bytes])
+	AC_TRY_RUN(
+int foo(int);
+main()
+{
+  exit(foo(0)!=16);
+}
+int foo(int x)
+{
+  if (x) {
+  label1:
+    asm("$i");
+  label2:
+  }
+  return (&&label2)-(&&label1);
+}
+	,AC_MSG_RESULT(yes)
+         AC_DEFINE_UNQUOTED(SKIP16,asm("$i"),statement for skipping 16 bytes)
+         break
+	,AC_MSG_RESULT(no),)
+	
+done	
+
+
 dnl Checks for programs.
 AC_PROG_LN_S
 dnl AM_PROG_INSTALL #performed by AM_INIT_AUTOMAKE
@@ -314,8 +351,8 @@ AC_REPLACE_FUNCS(memmove strtoul pow10 s
 AC_CHECK_FUNCS(dlopen sys_siglist getrusage)
 AC_DECL_SYS_SIGLIST
 AC_CHECK_FUNC(getopt_long,true,AC_LIBOBJ(getopt.$ac_objext getopt1))
-AC_CHECK_FUNCS(rint expm1 log1p)
-AC_REPLACE_FUNCS(ecvt)
+AC_CHECK_FUNCS(expm1 log1p)
+AC_REPLACE_FUNCS(rint ecvt)
 dnl No check for select, because our replacement is no good under
 dnl anything but DOS
 AC_CHECK_HEADERS(sys/mman.h fnmatch.h)