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/* -*- Mode: Asm -*- */
/* Copyright (c) 2002 Michael Stumpf <mistumpf@de.pepperl-fuchs.com>
Copyright (c) 2005 Anatoly Sokolov <aesok@post.ru>
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: ldexp.S,v 1.7.2.3 2006/01/06 14:30:17 aesok Exp $ */
/*
ldexp.S is part of FPlib V 0.3.0 ported to avr-as
for details see readme.fplib
*----------------------------------------------------------------------------------------
*
* A = 2^exp * x
* e.g.
* double y = ldexp( 3.45, 2 ) = 2^2 * 3.45 = 13.8
*/
#if !defined(__DOXYGEN__)
#include "gasava.inc"
#include "macros.inc"
#include "fplib.inc"
#define rExpH rBE
TEXT_SEG(fplib, ldexp)
FUNCTION(ldexp)
GLOBAL(ldexp)
RCALL _U(__fp_split_a) ; Non return if NaN; clears rAE
TST rA3 ;
BREQ .L_zero ; 2^x*0 = 0
CLR rExpH
ADD rA3, rPL ; rExpH.rA3 := sum of exponent and arg
ADC rExpH, rPH
BRVS .L_Inf ; overflow is possible for positive only
BRMI .L_zero ; if underflow return 0
LDI rPL, lo8(EMAX)
LDI rPH, hi8(EMAX)
CP rA3, rPL
CPC rExpH, rPH
BRGE .L_Inf ; if overflow return +/-Inf
RJMP _U(__fp_merge) ; rT0 must not be cleared : rAE=0 no rounding anyway
.L_zero:
RJMP _U(__fp_zero)
.L_Inf:
BRTS .L_mInf ; branch if arg negative
RJMP _U(__fp_p_inf)
.L_mInf:
RJMP _U(__fp_m_inf)
ENDFUNC
#endif /* not __DOXYGEN__ */
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