71 lines
2.7 KiB
C
71 lines
2.7 KiB
C
/*
|
|
(C) Copyright 2001,2006,
|
|
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 names of the copyright holders nor the names of their
|
|
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.
|
|
*/
|
|
#ifndef _TRUNC_H_
|
|
#define _TRUNC_H_ 1
|
|
|
|
#include <spu_intrinsics.h>
|
|
#include "headers/vec_literal.h"
|
|
|
|
/* Truncate the input downwards to the nearest integer.
|
|
*/
|
|
static __inline double _trunc(double x)
|
|
{
|
|
vec_uchar16 splat_hi = VEC_LITERAL(vec_uchar16, 0,1,2,3,0,1,2,3, 8,9,10,11, 8,9,10,11);
|
|
vec_int4 exp, shift;
|
|
vec_uint4 sign = VEC_LITERAL(vec_uint4, 0x80000000, 0, 0x80000000, 0);
|
|
vec_uint4 or_mask, and_mask, mask;
|
|
vec_double2 in, in_hi, out;
|
|
|
|
in = spu_promote(x, 0);
|
|
|
|
/* Construct a mask to remove the fraction bits. The mask
|
|
* depends on the exponent of the floating point
|
|
* input value.
|
|
*/
|
|
in_hi = spu_shuffle(in, in, splat_hi);
|
|
exp = spu_and(spu_rlmask((vec_int4)in_hi, -20), 0x7FF);
|
|
|
|
shift = spu_sub(VEC_LITERAL(vec_int4, 1023, 1043, 1023, 1043), exp);
|
|
or_mask = spu_andc(spu_cmpgt(shift, 0), sign);
|
|
|
|
and_mask = spu_rlmask(VEC_LITERAL(vec_uint4, 0xFFFFF, -1, 0xFFFFF, -1), shift);
|
|
mask = spu_or(spu_and(and_mask, spu_cmpgt(shift, -31)), or_mask);
|
|
|
|
/* Apply the mask and return the result.
|
|
*/
|
|
out = spu_andc(in, (vec_double2)(mask));
|
|
|
|
return (spu_extract(out, 0));
|
|
}
|
|
#endif /* _TRUNC_H_ */
|