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/* Copyright (c) 2002 Michael Stumpf <mistumpf@de.pepperl-fuchs.com>
Copyright (c) 2006 Dmitry Xmelkov
All rights reserved.
Redistribution and use in source and binary forms, with or without
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. */
/* $Id: fp_mpack.S,v 1.1 2007/01/14 14:54:19 dmix Exp $ */
#include "fp32def.h"
#include "asmdef.h"
/* float __fp_mpack (<non_standart>);
Merge parts of float value.
Input:
T - sign
rA3 - exponent
rA2.rA1.rA0 - mantissa
Possible input combinations:
exp==0 - zero or subnormal, mantissa shift to right is needed
exp==1, rA2 < 0x80 - subnormal
exp==1, rA2 >= 0x80 - normal
exp==2..254, rA2 >= 0x80 - normal
exp==255, rA2.rA1.rA0 == 0 - Infinity
exp==255, rA2.rA1.rA0 != 0 - NaN
*/
ENTRY __fp_mpack
cpi rA3, 255
breq 3f
subi rA3, 1
brcc 1f ; rA3 was > 0
lsr rA2
ror rA1
ror rA0
ror rAE
subi rA3, -1 ; rA3 := 0
1: cpi rA2, 0x80 ; C set, if rA2.7 == 0
2: sbci rA3, -1
3: lsl rA2
lsr rA3
ror rA2
bld rA3, 7 ; sign
ret
ENDFUNC
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