7529cdb3f6
The upcoming vectormath that will used to speed up the SPU version of Extras/BulletMultiThreaded depends on this.
87 lines
3.1 KiB
C
87 lines
3.1 KiB
C
/* asinf4 - Computes the inverse sine of all four slots of x
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Copyright (C) 2006, 2007 Sony Computer Entertainment Inc.
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All rights reserved.
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Redistribution and use in source and binary forms,
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with or without modification, are permitted provided that the
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following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of the Sony Computer Entertainment Inc nor the names
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of its contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <simdmath.h>
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#include <altivec.h>
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#include "common-types.h"
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vector float asinf4 (vector float x)
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{
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// positive = (x > 0)
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//
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vec_uint4 positive = (vec_uint4)vec_cmpgt(x,vec_splatsf4(0.0f));
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// x = absf(x)
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//
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x = vec_abs(x);
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// gtHalf = (|x| > 0.5)
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//
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vec_uint4 gtHalf = (vec_uint4)vec_cmpgt(x,vec_splatsf4(0.5f));
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// if (x > 0.5)
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// g = 0.5 - 0.5*x
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// x = -2 * sqrtf(g)
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// else
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// g = x * x
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//
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vec_float4 g = vec_sel(vec_madd(x,x,vec_splatsf4(0.0f)),vec_madd(vec_splatsf4(-0.5f),x,vec_splatsf4(0.5f)),gtHalf);
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x = vec_sel(x,vec_madd(vec_splatsf4(-2.0f),sqrtf4(g),vec_splatsf4(0.0f)),gtHalf);
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// Compute the polynomials and take their ratio
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// denom = (1.0f*g + -0.554846723e+1f)*g + 5.603603363f
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// num = x * g * (-0.504400557f * g + 0.933933258f)
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//
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vec_float4 denom = vec_add(g,vec_splatsf4(-5.54846723f));
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vec_float4 num = vec_madd(vec_splatsf4(-0.504400557f),g,vec_splatsf4(0.933933258f));
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denom = vec_madd(denom,g,vec_splatsf4(5.603603363f));
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num = vec_madd(vec_madd(x,g,vec_splatsf4(0.0f)),num,vec_splatsf4(0.0f));
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// x = x + num / denom
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//
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x = vec_add(x,divf4(num,denom));
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// if (x > 0.5)
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// x = x + M_PI_2
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//
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x = vec_sel(x,vec_add(x,vec_splatsf4(1.57079632679489661923f)),gtHalf);
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// if (!positive) x = -x
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//
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x = vec_sel((vec_float4)vec_xor(vec_splatsi4(0x80000000),(vec_int4)x),x,positive);
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return x;
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}
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