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/* -------------------------------------------------------------- */
/* (C)Copyright 2007,2008, */
/* International Business Machines Corporation */
/* 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 IBM Corporation nor the names of its */
/* 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. */
/* -------------------------------------------------------------- */
/* PROLOG END TAG zYx */
#ifdef __SPU__
#ifndef _LOG1PD2_H_
#define _LOG1PD2_H_ 1
#include <spu_intrinsics.h>
#include "simdmath.h"
#include "logd2.h"
#include "divd2.h"
#define LOG1PD2_P0 0.0000000000000000000000000e+00
#define LOG1PD2_P1 1.0000000000000000000000000e+00
#define LOG1PD2_P2 2.3771612265431403265836252e+00
#define LOG1PD2_P3 2.0034423569559494104908026e+00
#define LOG1PD2_P4 7.1309327316770110272159400e-01
#define LOG1PD2_P5 9.8219761968547217301228613e-02
#define LOG1PD2_P6 3.4385125174546914139650511e-03
#define LOG1PD2_Q0 1.0000000000000000000000000e+00
#define LOG1PD2_Q1 2.8771612265431403265836252e+00
#define LOG1PD2_Q2 3.1086896368941925317130881e+00
#define LOG1PD2_Q3 1.5583843494335058998956356e+00
#define LOG1PD2_Q4 3.6047236436186669283898709e-01
#define LOG1PD2_Q5 3.2620075387969869884496887e-02
#define LOG1PD2_Q6 6.8047193336239690346356479e-04
/*
* FUNCTION
* vector double _log1pd2(vector double x)
*
* DESCRIPTION
* The function _log1pd2 computes the natural logarithm of x + 1
* for each of the double word elements of x.
*
*/
static __inline vector double _log1pd2(vector double x)
{
vector double oned = spu_splats(1.0);
vector double rangehi = spu_splats(0.35);
vector double rangelo = spu_splats(0.0);
vector unsigned long long use_log;
vector double pr, qr;
vector double eresult;
vector double rresult;
vector double result;
/* Compiler Bug. Replace xbug with x when spu_cmp*() doesn't
* modify it's arguments! */
volatile vector double xbug = x;
use_log = spu_or(spu_cmpgt(xbug, rangehi), spu_cmpgt(rangelo, xbug));
/*
* Calculate directly using log(x+1)
*/
eresult = _logd2(spu_add(x, oned));
/*
* For x in [0.0,0.35], use a rational approximation.
*/
pr = spu_madd(x, spu_splats(LOG1PD2_P6), spu_splats(LOG1PD2_P5));
qr = spu_madd(x, spu_splats(LOG1PD2_Q6), spu_splats(LOG1PD2_Q5));
pr = spu_madd(pr, x, spu_splats(LOG1PD2_P4));
qr = spu_madd(qr, x, spu_splats(LOG1PD2_Q4));
pr = spu_madd(pr, x, spu_splats(LOG1PD2_P3));
qr = spu_madd(qr, x, spu_splats(LOG1PD2_Q3));
pr = spu_madd(pr, x, spu_splats(LOG1PD2_P2));
qr = spu_madd(qr, x, spu_splats(LOG1PD2_Q2));
pr = spu_madd(pr, x, spu_splats(LOG1PD2_P1));
qr = spu_madd(qr, x, spu_splats(LOG1PD2_Q1));
pr = spu_madd(pr, x, spu_splats(LOG1PD2_P0));
qr = spu_madd(qr, x, spu_splats(LOG1PD2_Q0));
rresult = _divd2(pr, qr);
/*
* Select either direct calculation or rational approximation.
*/
result = spu_sel(rresult, eresult, use_log);
return result;
}
#endif /* _LOG1PD2_H_ */
#endif /* __SPU__ */
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