/* -------------------------------------------------------------- */ /* (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 _ACOSF4_H_ #define _ACOSF4_H_ 1 #include #include "divf4.h" #include "sqrtf4.h" /* * FUNCTION * vector float _acosf4(vector float x) * * DESCRIPTION * The _acosf4 function computes the arc cosine for a vector of values x; * that is the values whose cosine is x. Results are undefined if x is * outside the range [-1, 1]. * * RETURNS * The _acosf4 function returns the arc cosine in radians and the value is * mathematically defined to be in the range [0, pi]. * */ static __inline vector float _acosf4(vector float x) { vec_float4 zero = spu_splats(0.0f); vec_float4 half = spu_splats(0.5f); vec_float4 one = spu_splats(1.0f); vec_float4 two = spu_splats(2.0f); vec_float4 pi = spu_splats(3.1415925026e+00f); vec_float4 pio2_hi = spu_splats(1.5707962513e+00f); vec_float4 pio2_lo = spu_splats(7.5497894159e-08f); vec_float4 snan = (vec_float4)spu_splats((unsigned int)0x7FC00000); vec_uint4 denorm_threshold = spu_splats((unsigned int)0x23000000); vec_uint4 sign_mask = spu_splats((unsigned int)0x80000000); vec_float4 p0 = (vec_float4)spu_splats((unsigned int)0x3E2AAAAB); vec_float4 p1 = (vec_float4)spu_splats((unsigned int)0xBEA6B090); vec_float4 p2 = (vec_float4)spu_splats((unsigned int)0x3E4E0AA8); vec_float4 p3 = (vec_float4)spu_splats((unsigned int)0xBD241146); vec_float4 p4 = (vec_float4)spu_splats((unsigned int)0x3A4F7F04); vec_float4 p5 = (vec_float4)spu_splats((unsigned int)0x3811EF08); vec_float4 q1 = (vec_float4)spu_splats((unsigned int)0xC019D139); vec_float4 q2 = (vec_float4)spu_splats((unsigned int)0x4001572D); vec_float4 q3 = (vec_float4)spu_splats((unsigned int)0xBF303361); vec_float4 q4 = (vec_float4)spu_splats((unsigned int)0x3D9DC62E); vec_uint4 x_abs = spu_andc((vec_uint4)x,sign_mask); vec_uint4 x_pos = spu_cmpgt(sign_mask,(vec_uint4)x); vec_uint4 almost_half = spu_splats((unsigned int)0x3EFFFFFF); vec_uint4 sel0 = spu_nand(spu_splats((unsigned int)0xFFFFFFFF),spu_cmpgt(x_abs,almost_half)); vec_uint4 sel1 = spu_andc(x_pos,sel0); // pos vec_float4 za = spu_sel(spu_sel(spu_add(one,x),spu_sub(one,x),sel1) ,x,sel0); vec_float4 zb = spu_sel(half,x,sel0); vec_float4 z = spu_mul(za,zb); vec_float4 p; p = spu_madd(z,p5,p4); p = spu_madd(p,z,p3); p = spu_madd(p,z,p2); p = spu_madd(p,z,p1); p = spu_madd(p,z,p0); p = spu_mul(p,z); vec_float4 q; q = spu_madd(z,q4,q3); q = spu_madd(q,z,q2); q = spu_madd(q,z,q1); q = spu_madd(q,z,one); // Only used by secondaries vec_float4 s = _sqrtf4(z); vec_float4 r = _divf4(p,q); vec_float4 w1 = spu_msub(r,s,pio2_lo); vec_float4 df = (vec_float4)spu_and((vec_uint4)s,0xFFFFF000); vec_float4 c = _divf4(spu_nmsub(df,df,z),spu_add(s,df)); vec_float4 w2 = spu_madd(r,s,c); vec_float4 result0 = spu_sub(pio2_hi,spu_sub(x,spu_nmsub(x,r,pio2_lo))); vec_float4 result1 = spu_mul(two,spu_add(df,w2)); vec_float4 result2 = spu_nmsub(two,spu_add(s,w1),pi); vec_float4 result; result = spu_sel(result2,result1,sel1); result = spu_sel(result,result0,sel0); // If |x|==1 then: // if x == 1, return 0 // else return pi vec_uint4 abs_one = spu_cmpeq(x_abs,(vec_uint4)one); vec_uint4 out_of_bounds = spu_cmpgt(x_abs,(vec_uint4)one); vec_uint4 underflow = spu_cmpgt(denorm_threshold,x_abs); result = spu_sel(result,spu_sel(pi,zero,x_pos),abs_one); // If 1 < |x| then return sNaN result = spu_sel(result,snan,out_of_bounds); // If |x| < 2**-57, then return pi/2 (OFF BY 1 ULP) result = spu_sel(result,spu_add(pio2_hi,pio2_lo),underflow); return result; } #endif /* _ACOSF4_H_ */ #endif /* __SPU__ */