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Diffstat (limited to 'newlib/libm/machine/spu/headers/tanhf4.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/tanhf4.h | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/newlib/libm/machine/spu/headers/tanhf4.h b/newlib/libm/machine/spu/headers/tanhf4.h deleted file mode 100644 index 6d45572b0..000000000 --- a/newlib/libm/machine/spu/headers/tanhf4.h +++ /dev/null @@ -1,135 +0,0 @@ -/* -------------------------------------------------------------- */ -/* (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 _TANHF4_H_ -#define _TANHF4_H_ 1 - -#include <spu_intrinsics.h> - -#include "expf4.h" -#include "divf4.h" - -#include "tanhd2.h" - -/* - * FUNCTION - * vector float _tanhf4(vector float x) - * - * DESCRIPTION - * The _tanhf4 function computes the hyperbolic tangent for each - * element of the input vector. - * - * We use the following to approximate tanh: - * - * |x| <= .25: Taylor Series - * |x| > .25: tanh(x) = (exp(2x) - 1)/(exp(2x) + 1) - * - * - * SPECIAL CASES: - * - tanh(+/- 0) = +/-0 - * - tanh(+/- infinity) = +/- 1 - * - */ - -static __inline vector float _tanhf4(vector float x) -{ - vector float signbit = spu_splats(-0.0f); - vector float onef = spu_splats(1.0f); - vector float twof = spu_splats(2.0f); - vector float xabs; - vector float x2; - vector unsigned int gttaylor; - vector float e; - vector float tresult; - vector float eresult; - vector float result; - - xabs = spu_andc(x, signbit); - - /* - * This is where we switch from Taylor Series - * to exponential formula. - */ - gttaylor = spu_cmpgt(xabs, spu_splats(0.25f)); - - - /* - * Taylor Series Approximation - */ - x2 = spu_mul(x,x); - tresult = spu_madd(x2, spu_splats((float)TANH_TAY06), spu_splats((float)TANH_TAY05)); - tresult = spu_madd(x2, tresult, spu_splats((float)TANH_TAY04)); - tresult = spu_madd(x2, tresult, spu_splats((float)TANH_TAY03)); - tresult = spu_madd(x2, tresult, spu_splats((float)TANH_TAY02)); - tresult = spu_madd(x2, tresult, spu_splats((float)TANH_TAY01)); - tresult = spu_mul(xabs, tresult); - - - /* - * Exponential Formula - * Our expf4 function gives a more accurate result in general - * with xabs instead of x for x<0. We correct for sign later. - */ - e = _expf4(spu_mul(xabs, twof)); - eresult = _divf4(spu_sub(e, onef), spu_add(e, onef)); - - - /* - * Select Taylor or exp result. - */ - result = spu_sel(tresult, eresult, gttaylor); - - /* - * Correct for accumulated truncation error when - * tanh(x) should return 1. - * Note that this also handles the special case of - * x = +/- infinity. - */ - result = spu_sel(result, onef, spu_cmpgt(xabs, spu_splats(9.125f))); - - /* - * Antisymmetric function - preserve sign bit of x - * in the result. - */ - result = spu_sel(result, x, (vec_uint4)signbit); - - return result; -} - -#endif /* _TANHF4_H_ */ -#endif /* __SPU__ */ |