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Diffstat (limited to 'newlib/libm/machine/spu/headers/log2f4.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/log2f4.h | 124 |
1 files changed, 0 insertions, 124 deletions
diff --git a/newlib/libm/machine/spu/headers/log2f4.h b/newlib/libm/machine/spu/headers/log2f4.h deleted file mode 100644 index 3853e91bb..000000000 --- a/newlib/libm/machine/spu/headers/log2f4.h +++ /dev/null @@ -1,124 +0,0 @@ -/* -------------------------------------------------------------- */ -/* (C)Copyright 2001,2008, */ -/* International Business Machines Corporation, */ -/* Sony Computer Entertainment, Incorporated, */ -/* Toshiba 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 _LOG2F4_H_ -#define _LOG2F4_H_ 1 - -#include <spu_intrinsics.h> - -/* - * FUNCTION - * vector float _log2f4(vector float x) - * - * DESCRIPTION - * The _log2f4 function computes log (base 2) on a vector if inputs - * values x. The _log2f4 function is approximated as a polynomial of - * order 8 (C. Hastings, Jr, 1955). - * - * __8__ - * \ - * \ - * log2f(1+x) = / Ci*x^i - * /____ - * i=1 - * - * for x in the range 0.0 to 1.0 - * - * C1 = 1.4426898816672 - * C2 = -0.72116591947498 - * C3 = 0.47868480909345 - * C4 = -0.34730547155299 - * C5 = 0.24187369696082 - * C6 = -0.13753123777116 - * C7 = 0.052064690894143 - * C8 = -0.0093104962134977 - * - * This function assumes that x is a non-zero positive value. - * - */ -static __inline vector float _log2f4(vector float x) -{ - vector signed int exponent; - vector float result; - vector float x2, x4; - vector float hi, lo; - - /* Extract the exponent from the input X. - */ - exponent = (vector signed int)spu_and(spu_rlmask((vector unsigned int)(x), -23), 0xFF); - exponent = spu_add(exponent, -127); - - /* Compute the remainder after removing the exponent. - */ - x = (vector float)spu_sub((vector signed int)(x), spu_sl(exponent, 23)); - - /* Calculate the log2 of the remainder using the polynomial - * approximation. - */ - x = spu_sub(x, spu_splats(1.0f)); - - /* Instruction counts can be reduced if the polynomial was - * computed entirely from nested (dependent) fma's. However, - * to reduce the number of pipeline stalls, the polygon is evaluated - * in two halves (hi amd lo). - */ - x2 = spu_mul(x, x); - x4 = spu_mul(x2, x2); - - hi = spu_madd(x, spu_splats(-0.0093104962134977f), spu_splats(0.052064690894143f)); - hi = spu_madd(x, hi, spu_splats(-0.13753123777116f)); - hi = spu_madd(x, hi, spu_splats( 0.24187369696082f)); - hi = spu_madd(x, hi, spu_splats(-0.34730547155299f)); - lo = spu_madd(x, spu_splats(0.47868480909345f), spu_splats(-0.72116591947498f)); - lo = spu_madd(x, lo, spu_splats(1.4426898816672f)); - lo = spu_mul(x, lo); - result = spu_madd(x4, hi, lo); - - /* Add the exponent back into the result. - */ - result = spu_add(result, spu_convtf(exponent, 0)); - - return (result); -} - -#endif /* _LOG2F4_H_ */ -#endif /* __SPU__ */ |