Minor improvements, code cleanup and license clarification

[fw/sdcc] / device / lib / z80 / strlen.s

diff --git a/device/lib/z80/strlen.s b/device/lib/z80/strlen.s
index 2eccf70d695caf87b016c6d69f06f526e55f683b..583a27add171af4f6e61ad7427f1f2ca420806eb 100644 (file)
--- a/device/lib/z80/strlen.s
+++ b/device/lib/z80/strlen.s
@@ -1,3 +1,31 @@
+; Copyright (C) 2008-2009
+; Philipp Klaus Krause
+
+; This file is part of the sdcc Library.  This library 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.
+
+; This library 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 library; see the file COPYING.  If not, write to the Free
+; Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+; USA.
+
+; As a special exception, you may use this file as part of a free software
+; library without restriction.  Specifically, if other files instantiate
+; templates or use macros or inline functions from this file, or you compile
+; this file and link it with other files to produce an executable, this
+; file does not by itself 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.
+
         .area   _CODE
 
        .globl _strlen
@@ -5,17 +33,15 @@
 ; The Z80 has the cpir instruction, which is perfect for implementing strlen().
 
 _strlen:
-       push    ix
-       ld      ix, #0
-       add     ix, sp
-       ld      l, 4(ix)
-       ld      h, 5(ix)
+       pop     bc
+       pop     hl
+       push    hl
+       push    bc
        xor     a, a
        ld      b, a
        ld      c, a
        cpir
        ld      hl, #-1
        sbc     hl, bc  ; C flag still cleared from xor above.
-       pop     ix
        ret