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Diffstat (limited to 'newlib/libm/machine/spu/headers/log1pf4.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/log1pf4.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/newlib/libm/machine/spu/headers/log1pf4.h b/newlib/libm/machine/spu/headers/log1pf4.h new file mode 100644 index 000000000..376aaaa72 --- /dev/null +++ b/newlib/libm/machine/spu/headers/log1pf4.h @@ -0,0 +1,124 @@ +/* -------------------------------------------------------------- */ +/* (C)Copyright 2006,2007, */ +/* 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. */ +/* 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 _LOG1PF4_H_ +#define _LOG1PF4_H_ 1 + +#include <spu_intrinsics.h> +#include "simdmath.h" + +#include "logf4.h" +#include "divf4.h" + +/* + * FUNCTION + * vector float _log1pf4(vector float x) + * + * DESCRIPTION + * The function _log1pf4 computes the natural logarithm of x + 1 + * for each of the float word elements of x. + * + * + */ + +#define LOG1PF4_P0 0.0000000000000000000000000e+00f +#define LOG1PF4_P1 1.0000000000000000000000000e+00f +#define LOG1PF4_P2 1.4220868022897381610647471e+00f +#define LOG1PF4_P3 5.4254553902256308361984338e-01f +#define LOG1PF4_P4 4.5971908823142115796400731e-02f + +#define LOG1PF4_Q0 1.0000000000000000000000000e+00f +#define LOG1PF4_Q1 1.9220868007537357247116461e+00f +#define LOG1PF4_Q2 1.1702556461286610645089468e+00f +#define LOG1PF4_Q3 2.4040413392943396631018516e-01f +#define LOG1PF4_Q4 1.0637426466449625625521058e-02f + + +static __inline vector float _log1pf4(vector float x) +{ + vector float onef = spu_splats(1.0f); + vector float range = spu_splats(0.35f); + vector unsigned int use_log; + vector float pr, qr; + vector float eresult; + vector float rresult; + vector float result; + + use_log = spu_cmpabsgt(x, range); + + /* + * Calculate directly using log(x+1) + */ + eresult = _logf4(spu_add(x, onef)); + + /* + * For x in [-0.35,0.35], use a rational approximation. + */ + pr = spu_madd(x, spu_splats((float)LOG1PF4_P4), spu_splats((float)LOG1PF4_P3)); + qr = spu_madd(x, spu_splats((float)LOG1PF4_Q4), spu_splats((float)LOG1PF4_Q3)); + pr = spu_madd(pr, x, spu_splats((float)LOG1PF4_P2)); + qr = spu_madd(qr, x, spu_splats((float)LOG1PF4_Q2)); + pr = spu_madd(pr, x, spu_splats((float)LOG1PF4_P1)); + qr = spu_madd(qr, x, spu_splats((float)LOG1PF4_Q1)); + pr = spu_madd(pr, x, spu_splats((float)LOG1PF4_P0)); + qr = spu_madd(qr, x, spu_splats((float)LOG1PF4_Q0)); + rresult = _divf4(pr, qr); + + /* + * Select either direct calculation or rational approximation. + */ + result = spu_sel(rresult, eresult, use_log); + + return result; +} + +#endif /* _LOG1PF4_H_ */ +#endif /* __SPU__ */ |