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[/] [openrisc/] [trunk/] [gnu-src/] [newlib-1.17.0/] [newlib/] [libm/] [machine/] [spu/] [headers/] [expm1d2.h] - Rev 148
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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 _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__ */
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