89 lines
4.4 KiB
C
89 lines
4.4 KiB
C
/* fmodf4 - for each of four float slots, compute remainder of x/y defined as x - truncated_integer(x/y) * y.
|
|
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_FMODF4_H___
|
|
#define ___SIMD_MATH_FMODF4_H___
|
|
|
|
#include <simdmath.h>
|
|
#include <altivec.h>
|
|
|
|
#include <simdmath/divf4.h>
|
|
#include <simdmath/fabsf4.h>
|
|
#include <simdmath/copysignf4.h>
|
|
|
|
//
|
|
// This returns an accurate result when |divf4(x,y)| < 2^20 and |x| < 2^128, and otherwise returns zero.
|
|
// If x == 0, the result is 0.
|
|
// If x != 0 and y == 0, the result is undefined.
|
|
|
|
static inline vector float
|
|
_fmodf4 (vector float x, vector float y)
|
|
{
|
|
vector float q, xabs, yabs, qabs, xabs2;
|
|
vector signed int qi0, qi1, qi2;
|
|
vector float i0, i1, i2, r1, r2, i;
|
|
vector unsigned int inrange;
|
|
|
|
// Find i = truncated_integer(|x/y|)
|
|
|
|
// If |divf4(x,y)| < 2^20, the quotient is at most off by 1.0.
|
|
// Thus i is either the truncated quotient, one less, or one greater.
|
|
|
|
q = _divf4( x, y );
|
|
xabs = _fabsf4( x );
|
|
yabs = _fabsf4( y );
|
|
qabs = _fabsf4( q );
|
|
xabs2 = vec_add( xabs, xabs );
|
|
|
|
inrange = (vector unsigned int)vec_cmpgt( (vector float)(__vec_splatsu4(0x49800000)), qabs );
|
|
|
|
qi1 = vec_cts( qabs, 0 );
|
|
qi0 = vec_add( qi1, __vec_splatsi4(-1) );
|
|
qi2 = vec_add( qi1, __vec_splatsi4(1) );
|
|
|
|
i0 = vec_ctf( qi0, 0 );
|
|
i1 = vec_ctf( qi1, 0 );
|
|
i2 = vec_ctf( qi2, 0 );
|
|
|
|
// Correct i will be the largest one such that |x| - i*|y| >= 0.
|
|
|
|
r1 = vec_nmsub( i1, yabs, xabs );
|
|
r2 = vec_nmsub( i2, yabs, xabs );
|
|
|
|
i = i0;
|
|
i = vec_sel( i1, i, vec_cmpgt( __vec_splatsi4(0), (vector signed int)r1 ) );
|
|
i = vec_sel( i2, i, vec_cmpgt( __vec_splatsi4(0), (vector signed int)r2 ) );
|
|
|
|
i = _copysignf4( i, q );
|
|
|
|
return vec_sel( __vec_splatsf4(0.0f), vec_nmsub( i, y, x ), inrange );
|
|
}
|
|
|
|
#endif
|