7529cdb3f6
The upcoming vectormath that will used to speed up the SPU version of Extras/BulletMultiThreaded depends on this.
66 lines
2.6 KiB
C
66 lines
2.6 KiB
C
/* expf4 -
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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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#define _EXPF_H_C1 ((float)-0.6931470632553101f)
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#define _EXPF_H_C2 ((float)-1.1730463525082e-7f)
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#define _EXPF_H_INVLN2 ((float)1.4426950408889634f)
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vector float
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expf4 (vector float x)
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{
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vec_float4 zeros = vec_splatsf4(0.0f);
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vec_uint4 xnegmask = (vec_uint4)vec_cmpgt(zeros, x);
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vec_float4 goffset = vec_sel(vec_splatsf4( 0.5f),vec_splatsf4(-0.5f),xnegmask);
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vec_float4 g = vec_madd(x, vec_splatsf4(_EXPF_H_INVLN2), zeros);
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vec_int4 xexp = vec_cts(vec_add(g, goffset),0);
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g = vec_ctf(xexp, 0);
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g = vec_madd(g, vec_splatsf4(_EXPF_H_C2), vec_madd(g, vec_splatsf4(_EXPF_H_C1), x));
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vec_float4 z = vec_madd(g, g, zeros);
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vec_float4 a = vec_madd(z, vec_splatsf4(0.0999748594f), zeros);
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vec_float4 b = vec_madd(g,
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vec_madd(z,
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vec_splatsf4(0.0083208258f),
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vec_splatsf4(0.4999999992f)
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),
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zeros);
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vec_float4 foo = divf4(vec_add(vec_splatsf4(1.0f), vec_add(a, b)),
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vec_add(vec_splatsf4(1.0f), vec_sub(a, b)));
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return ldexpf4(foo, xexp);
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}
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