# mul10.S

/* Copyright (c) 2002, 2006, 2007 Marek Michalkiewicz

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modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
* Neither the name of the copyright holders nor the names of
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE. */

/*
mul10.S - optimized 16-bit multiply by 10

Contributors:
Created by Marek Michalkiewicz <marekm@linux.org.pl>
*/

#if !defined(__DOXYGEN__)

#include "macros.inc"

#define r_hi r25
#define r_lo r24
#define r_tmp2 r23
#define r_tmp_lo r22
#define r_tmp_hi r23

/*
r_hi:r_lo *= 10

Optimized version, without calling __mulhi3 (which is slow for
non-enhanced core, and not present in libgcc.a for enhanced core).
*/

ASSEMBLY_CLIB_SECTION
.global _U(__mulhi_const_10)

_U(__mulhi_const_10):
#if defined(__AVR_HAVE_MUL__)
ldi r_tmp2,10
mul r_hi,r_tmp2
mov r_hi,r0
mul r_lo,r_tmp2
mov r_lo,r0
clr r1  ; __zero_reg__
#else
X_movw  r_tmp_lo, r_lo