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95 lines
3.8 KiB
C
95 lines
3.8 KiB
C
/*
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(C) Copyright 2001,2006,
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International Business Machines Corporation,
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Sony Computer Entertainment, Incorporated,
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Toshiba Corporation,
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice,
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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 names of the copyright holders nor the names of their
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contributors may be used to endorse or promote products derived from this
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software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
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OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef _FLOOR_H_
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#define _FLOOR_H_ 1
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#include <spu_intrinsics.h>
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#include "headers/vec_literal.h"
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/* Round the input downwards to the nearest integer.
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*/
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static __inline double _floor(double x)
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{
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vec_uchar16 swap_words = VEC_LITERAL(vec_uchar16, 4,5,6,7, 0,1,2,3, 12,13,14,15, 8,9,10,11);
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vec_uchar16 splat_hi = VEC_LITERAL(vec_uchar16, 0,1,2,3,0,1,2,3, 8,9,10,11, 8,9,10,11);
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vec_uint4 one = VEC_LITERAL(vec_uint4, 0, 1, 0, 1);
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vec_int4 exp, shift;
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vec_uint4 mask, mask_1, frac_mask, addend, insert, pos, equal0;
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vec_ullong2 sign = VEC_SPLAT_U64(0x8000000000000000ULL);
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vec_double2 in, in_hi, out;
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vec_double2 minus_one = VEC_SPLAT_F64(-1.0);
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in = spu_promote(x, 0);
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/* This function generates the following component
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* based upon the inputs.
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*
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* mask = bits of the input that need to be replaced.
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* insert = value of the bits that need to be replaced
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* addend = value to be added to perform function.
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*
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* These are applied as follows:.
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*
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* out = ((in & mask) | insert) + addend
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*/
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in_hi = spu_shuffle(in, in, splat_hi);
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pos = spu_cmpgt((vec_int4)in_hi, -1);
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exp = spu_and(spu_rlmask((vec_int4)in_hi, -20), 0x7FF);
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shift = spu_sub(VEC_LITERAL(vec_int4, 1023, 1043, 1023, 1043), exp);
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/* clamp shift to the range 0 to -31.
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*/
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shift = spu_sel(VEC_SPLAT_S32(-32), spu_andc(shift, (vec_int4)spu_cmpgt(shift, 0)), spu_cmpgt(shift, -32));
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frac_mask = spu_rlmask(VEC_LITERAL(vec_uint4, 0xFFFFF, -1, 0xFFFFF, -1), shift);
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mask = spu_orc(frac_mask, spu_cmpgt(exp, 0x3FE));
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/* addend = ((in & mask) && (in >= 0)) ? mask+1 : 0
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*/
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mask_1 = spu_addx(mask, one, spu_rlqwbyte(spu_genc(mask, one), 4));
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equal0 = spu_cmpeq(spu_and((vec_uint4)in, mask), 0);
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addend = spu_andc(spu_andc(mask_1, pos),
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spu_and(equal0, spu_shuffle(equal0, equal0, swap_words)));
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insert = spu_andc(spu_andc((vec_uint4)minus_one, pos),
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spu_cmpgt((vec_uint4)spu_add(exp, -1), 1022));
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in = spu_sel(in, (vec_double2)insert, spu_andc((vec_ullong2)mask, sign));
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out = (vec_double2)spu_addx((vec_uint4)in, addend,
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spu_rlqwbyte(spu_genc((vec_uint4)in, addend), 4));
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return (spu_extract(out, 0));
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}
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#endif /* _FLOOR_H_ */
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