newlib-cygwin/newlib/libm/machine/spu/headers/tanf4.h

113 lines
5.2 KiB
C

/* -------------------------------------------------------------- */
/* (C)Copyright 2006,2007, */
/* International Business Machines Corporation, */
/* Sony Computer Entertainment, Incorporated, */
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/* copyright notice, this list of conditions and the following */
/* disclaimer in the documentation and/or other materials */
/* provided with the distribution. */
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/* PROLOG END TAG zYx */
#ifdef __SPU__
#ifndef _TANF4_H_
#define _TANF4_H_ 1
#include <spu_intrinsics.h>
#include "cos_sin.h"
#include "divf4.h"
/*
* FUNCTION
* vector float _tanf4(vector float angle)
*
* DESCRIPTION
* The _tanf4 function computes the tangent of a vector of "angle"s
* (expressed in radians) to an accuracy of single precision floating
* point.
*
*/
static __inline vector float _tanf4(vector float angle)
{
vec_int4 octant;
vec_uint4 select;
vec_float4 cos, sin;
vec_float4 num, den;
vec_float4 toggle_sign, answer;
/* Range reduce the input angle x into the range -PI/4 to PI/4
* by performing simple modulus.
*/
MOD_PI_OVER_FOUR_F(angle, octant);
/* Compute the cosine and sine of the range reduced input.
*/
COMPUTE_COS_SIN_F(angle, cos, sin);
/* For each SIMD element, select the numerator, denominator, and sign
* correction depending upon the octant of the original angle.
*
* octants angles numerator denominator sign toggle
* ------- ------------ --------- ----------- -----------
* 0 0 to 45 sin cos no
* 1,2 45 to 135 cos sin no,yes
* 3,4 135 to 225 sin cos yes,no
* 5,6 225 to 315 cos sin no,yes
* 7 315 to 360 sin cos yes
*/
toggle_sign = (vec_float4)spu_sl(spu_and(octant, 2), 30);
select = spu_cmpeq(spu_and(octant, 2), 0);
num = spu_sel(cos, sin, select);
den = spu_sel(sin, cos, select);
answer = spu_xor(_divf4(num, den), toggle_sign);
return (answer);
}
#endif /* _TANF4_H_ */
#endif /* __SPU__ */