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bullet3/Extras/simdmathlibrary/spu/simdmath/nextafterd2.h
2007-07-27 18:53:58 +00:00

98 lines
4.2 KiB
C

/* nextafterd2 - find next representable floating-point value towards 2nd param.
Copyright (C) 2006, 2007 Sony Computer Entertainment Inc.
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 name of the Sony Computer Entertainment Inc nor the names
of its 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 ___SIMD_MATH_NEXTAFTERD2_H___
#define ___SIMD_MATH_NEXTAFTERD2_H___
#include <simdmath.h>
#include <spu_intrinsics.h>
static inline vector double
_nextafterd2 (vector double xx, vector double yy)
{
vec_uint4 abs_x, abs_y, sign_x, abs_dif;
vec_uint4 is_sub, is_zerox, is_zeroy;
vec_uint4 is_equal, is_infy, is_nany;
vec_uint4 res0, res1, res;
vec_uint4 vec_zero = ((vec_uint4){0,0,0,0});
vec_uint4 vec_one = ((vec_uint4){0,1,0,1});
vec_uint4 vec_m1 = ((vec_uint4){0x80000000,1,0x80000000,1});
vec_uint4 msk_exp = ((vec_uint4){0x7FF00000,0,0x7FF00000,0});
vec_uint4 msk_abs = ((vec_uint4){0x7FFFFFFF,-1,0x7FFFFFFF,-1});
vec_uchar16 msk_all_eq = ((vec_uchar16){4,5,6,7,0,1,2,3,12,13,14,15,8,9,10,11});
// mask sign bit
abs_x = spu_and( (vec_uint4)xx, msk_abs);
abs_y = spu_and( (vec_uint4)yy, msk_abs);
is_zerox = spu_cmpeq( abs_x, vec_zero);
is_zerox = spu_and( is_zerox, spu_shuffle(is_zerox,is_zerox,msk_all_eq));
// -0 exception
sign_x = spu_and((vec_uint4)xx, ((vec_uint4){0x80000000,0,0x80000000,0}));
sign_x = spu_sel(sign_x, vec_zero, is_zerox);
// if same sign |y| < |x| -> decrease
abs_dif = spu_subx(abs_y, abs_x, spu_rlqwbyte(spu_genb(abs_y, abs_x), 4));
is_sub = spu_xor((vec_uint4)yy, sign_x); // not same sign -> decrease
is_sub = spu_or(is_sub, abs_dif);
is_sub = spu_rlmaska(is_sub, -31);
is_sub = spu_shuffle(is_sub,is_sub,((vec_uchar16){0,0,0,0,0,0,0,0,8,8,8,8,8,8,8,8}));
res0 = spu_addx( abs_x, vec_one, spu_rlqwbyte(spu_genc(abs_x,vec_one),4)); // calc increase
res1 = spu_subx( abs_x, vec_one, spu_rlqwbyte(spu_genb(abs_x,vec_one),4)); // calc decrease
res = spu_sel( res0, res1, is_sub); // select increase or decrease
res = spu_or( res, sign_x); // set sign
// check exception
// 0 -> -1
res = spu_sel(res, vec_m1, spu_and(is_zerox, is_sub));
// check equal (include 0,-0)
is_zeroy = spu_cmpeq( abs_y, vec_zero);
is_zeroy = spu_and( is_zeroy, spu_shuffle(is_zeroy,is_zeroy,msk_all_eq));
is_equal = spu_cmpeq((vec_uint4)xx, (vec_uint4)yy);
is_equal = spu_and(is_equal, spu_shuffle(is_equal,is_equal,msk_all_eq));
is_equal = spu_or(is_equal, spu_and(is_zeroy, is_zerox));
res = spu_sel(res, (vec_uint4)yy, is_equal);
// check nan
is_infy = spu_cmpeq( abs_y, msk_exp);
is_infy = spu_and( is_infy, spu_shuffle(is_infy,is_infy,msk_all_eq));
is_nany = spu_and( abs_y, msk_exp);
is_nany = spu_cmpeq( is_nany, msk_exp);
is_nany = spu_and( is_nany, spu_shuffle(is_nany,is_nany,msk_all_eq));
is_nany = spu_sel( is_nany, vec_zero, is_infy);
res = spu_sel(res, (vec_uint4)yy, is_nany);
return (vec_double2)res;
}
#endif