# strupr.S

/* Copyright (c) 2002, 2007 Reiner Patommel

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* Redistributions in binary form must reproduce the above copyright
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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
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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. */

/* $Id$ */

/*
strupr.S
Convert a string to upper case

Contributors:
Created by Reiner Patommel
*/

/** \file */

/** \ingroup avr_string
\fn char *strupr(char *s)
\brief Convert a string to upper case.

The strupr() function will convert a string to upper case. Only the lower
case alphabetic characters [a .. z] are converted.  Non-alphabetic
characters will not be changed.

\returns The strupr() function returns a pointer to the converted
string.  The pointer is the same as that passed in since the operation is
perform in place. */

#if !defined(__DOXYGEN__)

#include "macros.inc"

#define str_hi r25
#define str_lo r24
#define temp   r22

ASSEMBLY_CLIB_SECTION
.global _U(strupr)
.type   _U(strupr), @function

_U(strupr):
X_movw  XL, str_lo

1:      ld      temp, X
subi    temp, 'a'
cpi     temp, 'z'-'a'+1
brlo    2f              ; if tepm is a..z, then temp += 'A'-'a'
subi    temp, 'A'-'a'   ; else restore temp
2:      subi    temp, -'A'
st      X+, temp
brne    1b              ; Z for temp
ret

.size   _U(strupr), . - _U(strupr)

#endif /* not __DOXYGEN__ */