Files
bullet3/Extras/simdmathlibrary/spu/cosf4.c
ejcoumans 7529cdb3f6 Added SCE SIMD math library in Extras/simdmathlibrary
The upcoming vectormath that will used to speed up the SPU version of Extras/BulletMultiThreaded depends on this.
2007-07-23 04:58:24 +00:00

95 lines
3.7 KiB
C

/* cosf4 - Computes the cosine of each of the four slots by using a polynomial approximation
Copyright (C) 2006, 2007 Sony Computer Entertainment Inc.
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 the Sony Computer Entertainment Inc 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.
*/
#include <simdmath.h>
#include <spu_intrinsics.h>
#include "sincos_c.h"
vector float
cosf4 (vector float x)
{
vec_float4 xl,xl2,xl3,res;
vec_int4 q;
// Range reduction using : xl = angle * TwoOverPi;
//
xl = spu_mul(x, spu_splats(0.63661977236f));
// Find the quadrant the angle falls in
// using: q = (int) (ceil(abs(xl))*sign(xl))
//
xl = spu_add(xl,spu_sel(spu_splats(0.5f),xl,spu_splats(0x80000000)));
q = spu_convts(xl,0);
// Compute an offset based on the quadrant that the angle falls in
//
vec_int4 offset = spu_add(spu_splats(1),spu_and(q,spu_splats((int)0x3)));
// Remainder in range [-pi/4..pi/4]
//
vec_float4 qf = spu_convtf(q,0);
vec_float4 p1 = spu_nmsub(qf,spu_splats(_SINCOS_KC1),x);
xl = spu_nmsub(qf,spu_splats(_SINCOS_KC2),p1);
// Compute x^2 and x^3
//
xl2 = spu_mul(xl,xl);
xl3 = spu_mul(xl2,xl);
// Compute both the sin and cos of the angles
// using a polynomial expression:
// cx = 1.0f + xl2 * ((C0 * xl2 + C1) * xl2 + C2), and
// sx = xl + xl3 * ((S0 * xl2 + S1) * xl2 + S2)
//
vec_float4 ct1 = spu_madd(spu_splats(_SINCOS_CC0),xl2,spu_splats(_SINCOS_CC1));
vec_float4 st1 = spu_madd(spu_splats(_SINCOS_SC0),xl2,spu_splats(_SINCOS_SC1));
vec_float4 ct2 = spu_madd(ct1,xl2,spu_splats(_SINCOS_CC2));
vec_float4 st2 = spu_madd(st1,xl2,spu_splats(_SINCOS_SC2));
vec_float4 cx = spu_madd(ct2,xl2,spu_splats(1.0f));
vec_float4 sx = spu_madd(st2,xl3,xl);
// Use the cosine when the offset is odd and the sin
// when the offset is even
//
vec_uchar16 mask1 = (vec_uchar16)spu_cmpeq(spu_and(offset,(int)0x1),spu_splats((int)0));
res = spu_sel(cx,sx,mask1);
// Flip the sign of the result when (offset mod 4) = 1 or 2
//
vec_uchar16 mask2 = (vec_uchar16)spu_cmpeq(spu_and(offset,(int)0x2),spu_splats((int)0));
res = spu_sel((vec_float4)spu_xor(spu_splats(0x80000000),(vec_uint4)res),res,mask2);
return res;
}