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71 lines
2.7 KiB
C
71 lines
2.7 KiB
C
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/*
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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 _TRUNC_H_
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#define _TRUNC_H_ 1
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#include <spu_intrinsics.h>
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#include "headers/vec_literal.h"
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/* Truncate the input downwards to the nearest integer.
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*/
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static __inline double _trunc(double x)
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{
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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_int4 exp, shift;
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vec_uint4 sign = VEC_LITERAL(vec_uint4, 0x80000000, 0, 0x80000000, 0);
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vec_uint4 or_mask, and_mask, mask;
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vec_double2 in, in_hi, out;
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in = spu_promote(x, 0);
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/* Construct a mask to remove the fraction bits. The mask
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* depends on the exponent of the floating point
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* input value.
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*/
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in_hi = spu_shuffle(in, in, splat_hi);
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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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or_mask = spu_andc(spu_cmpgt(shift, 0), sign);
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and_mask = spu_rlmask(VEC_LITERAL(vec_uint4, 0xFFFFF, -1, 0xFFFFF, -1), shift);
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mask = spu_or(spu_and(and_mask, spu_cmpgt(shift, -31)), or_mask);
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/* Apply the mask and return the result.
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*/
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out = spu_andc(in, (vec_double2)(mask));
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return (spu_extract(out, 0));
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}
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#endif /* _TRUNC_H_ */
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