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Diffstat (limited to 'newlib/libm/machine/spu/headers/expm1d2.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/expm1d2.h | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/newlib/libm/machine/spu/headers/expm1d2.h b/newlib/libm/machine/spu/headers/expm1d2.h new file mode 100644 index 000000000..18149f7e0 --- /dev/null +++ b/newlib/libm/machine/spu/headers/expm1d2.h @@ -0,0 +1,147 @@ +/* -------------------------------------------------------------- */ +/* (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 _EXPM1D2_H_ +#define _EXPM1D2_H_ 1 + +#include <spu_intrinsics.h> + +#include "expd2.h" +#include "divd2.h" + +#define EXPM1_P0 0.0000000000000000000000000e+00 +#define EXPM1_P1 1.0000000000000000000000000e+00 +#define EXPM1_P2 9.7234232565378004697204117e-04 +#define EXPM1_P3 3.3328278237299953368211192e-02 +#define EXPM1_P4 3.1156225044634678993365345e-05 +#define EXPM1_P5 2.1352206553343212164751408e-04 +#define EXPM1_P6 1.6975135794626144795757452e-07 +#define EXPM1_P7 2.7686287801334994383131629e-07 +#define EXPM1_P8 1.1186114936216450015354379e-10 + +#define EXPM1_Q0 1.0000000000000000000000000e+00 +#define EXPM1_Q1 -4.9902765767434620336473472e-01 +#define EXPM1_Q2 1.1617544040780639069687652e-01 +#define EXPM1_Q3 -1.6551954366467523660499950e-02 +#define EXPM1_Q4 1.5864115838972218334307351e-03 +#define EXPM1_Q5 -1.0534540477401370666288988e-04 +#define EXPM1_Q6 4.7650003993592160620959043e-06 +#define EXPM1_Q7 -1.3529198871087017840776265e-07 +#define EXPM1_Q8 1.8635779407675460757658020e-09 + +/* + * FUNCTION + * vector double _expm1d2(vector double x) + * + * DESCRIPTION + * _expm1d2 computes the exponential - 1 for each element + * of the input vector x. + * + * This function is intended to return accurate values, even + * where exp(x) - 1 would normally produce bad results due to + * floating-point cancellation errors. + * + */ + +static __inline vector double _expm1d2(vector double x) +{ + vector double oned = spu_splats(1.0); + vector double range = spu_splats(1.0625); + vector unsigned long long use_exp; + 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_exp = spu_cmpabsgt(xbug, range); + + /* + * Calculate directly using exp(x) - 1 + */ + eresult = spu_sub(_expd2(x), oned); + + /* + * For x in [-1.0625,1.0625], use a rational approximation. + * The madd's are interleaved to reduce dependency stalls. Looks + * like gcc is smart enough to do this on it's own... but why + * take the chance. + */ + pr = spu_madd(x, spu_splats(EXPM1_P8), spu_splats(EXPM1_P7)); + qr = spu_madd(x, spu_splats(EXPM1_Q8), spu_splats(EXPM1_Q7)); + pr = spu_madd(pr, x, spu_splats(EXPM1_P6)); + qr = spu_madd(qr, x, spu_splats(EXPM1_Q6)); + pr = spu_madd(pr, x, spu_splats(EXPM1_P5)); + qr = spu_madd(qr, x, spu_splats(EXPM1_Q5)); + pr = spu_madd(pr, x, spu_splats(EXPM1_P4)); + qr = spu_madd(qr, x, spu_splats(EXPM1_Q4)); + pr = spu_madd(pr, x, spu_splats(EXPM1_P3)); + qr = spu_madd(qr, x, spu_splats(EXPM1_Q3)); + pr = spu_madd(pr, x, spu_splats(EXPM1_P2)); + qr = spu_madd(qr, x, spu_splats(EXPM1_Q2)); + pr = spu_madd(pr, x, spu_splats(EXPM1_P1)); + qr = spu_madd(qr, x, spu_splats(EXPM1_Q1)); + pr = spu_madd(pr, x, spu_splats(EXPM1_P0)); + qr = spu_madd(qr, x, spu_splats(EXPM1_Q0)); + rresult = _divd2(pr, qr); + + /* + * Select either direct calculation or rational approximation. + */ + result = spu_sel(rresult, eresult, use_exp); + + return result; +} + +#endif /* _EXPM1D2_H_ */ +#endif /* __SPU__ */ |