[avr-libc-commit] [2136] Submitted by Krzysztof Kosciuszkiewicz:

[Joerg Wunsch]

Revision: 2136
          http://svn.sv.gnu.org/viewvc/?view=rev&root=avr-libc&revision=2136
Author:   joerg_wunsch
Date:     2010-06-08 12:03:38 +0000 (Tue, 08 Jun 2010)
Log Message:
-----------
Submitted by Krzysztof Kosciuszkiewicz:
patch #6690: Shorten calculation of dallas 1-wire crc
* include/util/crc16.h (_crc_ibutton_update): no need to
use the T flag bit to save bit 0 of the operand

Ticket Links:
:-----------
    http://savannah.gnu.org/patch/?6690

Modified Paths:
--------------
    trunk/avr-libc/ChangeLog
    trunk/avr-libc/NEWS
    trunk/avr-libc/include/util/crc16.h

Modified: trunk/avr-libc/ChangeLog
===================================================================
--- trunk/avr-libc/ChangeLog    2010-06-08 11:28:03 UTC (rev 2135)
+++ trunk/avr-libc/ChangeLog    2010-06-08 12:03:38 UTC (rev 2136)
@@ -1,5 +1,12 @@
 2010-06-08  Joerg Wunsch <address@hidden>
 
+       Submitted by Krzysztof Kosciuszkiewicz:
+       patch #6690: Shorten calculation of dallas 1-wire crc
+       * include/util/crc16.h (_crc_ibutton_update): no need to
+       use the T flag bit to save bit 0 of the operand
+
+2010-06-08  Joerg Wunsch <address@hidden>
+
        Submitted by Tero Sinervo:
        patch #6791: Minor fixes to stdio.h documentation
        * include/stdio.h: Fix spelling mistakes.

Modified: trunk/avr-libc/NEWS
===================================================================
--- trunk/avr-libc/NEWS 2010-06-08 11:28:03 UTC (rev 2135)
+++ trunk/avr-libc/NEWS 2010-06-08 12:03:38 UTC (rev 2136)
@@ -280,6 +280,7 @@
   [#6500] Reentrant code faq
   [#6517] Pgmspace with float support
   [#6649] sqrt.S in libm changes
+  [#6690] Shorten calculation of dallas 1-wire crc
   [#6718] Optimize the EEPROM functions
   [#6720] FAQ update. Add EEPROM section, baud rate section. Correct spelling.
   [#6791] Minor fixes to stdio.h documentation

Modified: trunk/avr-libc/include/util/crc16.h
===================================================================
--- trunk/avr-libc/include/util/crc16.h 2010-06-08 11:28:03 UTC (rev 2135)
+++ trunk/avr-libc/include/util/crc16.h 2010-06-08 12:03:38 UTC (rev 2136)
@@ -322,9 +322,8 @@
                "       eor     %0, %4" "\n\t"
                "       ldi     %1, 8" "\n\t"
                "       ldi     %2, 0x8C" "\n\t"
-               "1:     bst     %0, 0" "\n\t"
-               "       lsr     %0" "\n\t"
-               "       brtc    2f" "\n\t"
+               "1:     lsr     %0" "\n\t"
+               "       brcc    2f" "\n\t"
                "       eor     %0, %2" "\n\t"
                "2:     dec     %1" "\n\t"
                "       brne    1b" "\n\t"