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Diffstat (limited to 'newlib/libm/machine/spu/headers/atand2.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/atand2.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/newlib/libm/machine/spu/headers/atand2.h b/newlib/libm/machine/spu/headers/atand2.h new file mode 100644 index 000000000..27d55c9b3 --- /dev/null +++ b/newlib/libm/machine/spu/headers/atand2.h @@ -0,0 +1,115 @@ +/* -------------------------------------------------------------- */ +/* (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 _ATAND2_H_ +#define _ATAND2_H_ 1 + +#include <spu_intrinsics.h> + +#include "simdmath.h" +#include "recipd2.h" +#include "logd2.h" +#include "acosd2.h" +#include "asind2.h" +#include "sqrtd2.h" + +/* + * FUNCTION + * vector double _atand2(vector double x) + * + * DESCRIPTION + * The _atand2 function computes the arc tangent of a vector of values x. + * + * The arc tangent function is computed using the following relations: + * [0, 1] : arcsin(x1/sqrt(spu_add(x1squ + 1 ))); + * (1, infinity] : PI/2 + atanf(-1/x) + * [-infinity, 0) : -arcsin(|x|) + * + */ + +static __inline vector double _atand2(vector double x) +{ + vector double signbit = spu_splats(-0.0); + vector double oned = spu_splats(1.0); + vector double pi2 = spu_splats(SM_PI_2); + vector double xabs, x1; + vector double result; + vector unsigned long long gt1; + + xabs = spu_andc(x, signbit); + gt1 = spu_cmpgt(xabs, oned); + + /* + * For x > 1, use the relation: + * atan(x) = pi/2 - atan(1/x), x>1 + */ + x1 = spu_sel(xabs, _recipd2(xabs), gt1); + + vector double x1squ = spu_mul(x1, x1); + + result = _asind2(_divd2(x1, _sqrtd2(spu_add(x1squ, oned)))); + + /* + * For x > 1, use the relation: atan(x) = pi/2 - atan(1/x), x>1 + */ + result = spu_sel(result, spu_sub(pi2, result), gt1); + + /* + * Antisymmetric function - preserve sign of x in result. + */ + result = spu_sel(result, x, (vec_ullong2)signbit); + + return (result); +} + +#endif /* _ATAND2_H_ */ +#endif /* __SPU__ */ |