* config/i386/cygwin.asm. Add copyright notice. Add comment

	on why this code is needed.

From-SVN: r72869

gcc/ChangeLog

+2003-10-24  Danny Smith  <dannysmith@users.sourceforge.net>
+
+	* config/i386/cygwin.asm. Add copyright notice. Add comment
+	on why this code is needed.
+
 2003-10-23  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* config/h8300/clzhi2.c: Fix warnings.

gcc/config/i386/cygwin.asm

-/* stuff needed for libgcc on win32.  */
+/* stuff needed for libgcc on win32.
+ *
+ *   Copyright (C) 1996, 1998, 2001, 2003 Free Software Foundation, Inc.
+ *   Written By Steve Chamberlain
+ * 
+ * This file is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ * 
+ * In addition to the permissions in the GNU General Public License, the
+ * Free Software Foundation gives you unlimited permission to link the
+ * compiled version of this file with other programs, and to distribute
+ * those programs without any restriction coming from the use of this
+ * file.  (The General Public License restrictions do apply in other
+ * respects; for example, they cover modification of the file, and
+ * distribution when not linked into another program.)
+ * 
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ * 
+ *    As a special exception, if you link this library with files
+ *    compiled with GCC to produce an executable, this does not cause
+ *    the resulting executable to be covered by the GNU General Public License.
+ *    This exception does not however invalidate any other reasons why
+ *    the executable file might be covered by the GNU General Public License.
+ */
 
 #ifdef L_chkstk
 
+/* Function prologue calls _alloca to probe the stack when allocating more
+   than CHECK_STACK_LIMIT bytes in one go.  Touching the stack at 4K
+   increments is necessary to ensure that the guard pages used
+   by the OS virtual memory manger are allocated in correct sequence.  */
+
 	.global ___chkstk
 	.global	__alloca
 ___chkstk:
@@ -27,6 +65,4 @@ done: 	subl   %eax,%ecx
 	movl   (%eax),%ecx	/* recover saved temp */
 	movl   4(%eax),%eax	/* get return address */
 	jmp    *%eax	
-
-
 #endif