103 lines
3.7 KiB
C
103 lines
3.7 KiB
C
/* divu4 -
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Copyright (C) 2006, 2007 Sony Computer Entertainment Inc.
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All rights reserved.
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Redistribution and use in source and binary forms,
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with or without modification, are permitted provided that the
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following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, 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 name of the Sony Computer Entertainment Inc nor the names
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of its contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef ___SIMD_MATH_DIVU4_H___
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#define ___SIMD_MATH_DIVU4_H___
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#include <simdmath.h>
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#include <spu_intrinsics.h>
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// divu4 - for each of four unsigned integer slots, compute quotient and remainder of numer/denom
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// and store in divu4_t struct. Divide by zero produces quotient = 0, remainder = numerator.
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static inline divu4_t
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_divu4 (vector unsigned int numer, vector unsigned int denom)
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{
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divu4_t res;
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vec_int4 shift;
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vec_uint4 quot, newQuot;
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vec_uint4 denomZeros, numerZeros, denomLeft, oneLeft, denomShifted, oneShifted;
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vec_uint4 newNum, skip, cont;
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int anyCont;
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// Get difference of leading zeros.
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// Any possible negative value will be interpreted as a shift > 31
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denomZeros = spu_cntlz( denom );
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numerZeros = spu_cntlz( numer );
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shift = (vec_int4)spu_sub( denomZeros, numerZeros );
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// Shift denom to align leading one with numerator's
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denomShifted = spu_sl( denom, (vec_uint4)shift );
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oneShifted = spu_sl( spu_splats(1U), (vec_uint4)shift );
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oneShifted = spu_sel( oneShifted, spu_splats(0U), spu_cmpeq( denom, 0 ) );
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// Shift left all leading zeros.
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denomLeft = spu_sl( denom, denomZeros );
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oneLeft = spu_sl( spu_splats(1U), denomZeros );
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quot = spu_splats(0U);
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do
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{
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cont = spu_cmpgt( oneShifted, 0U );
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anyCont = spu_extract( spu_gather( cont ), 0 );
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newQuot = spu_or( quot, oneShifted );
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// Subtract shifted denominator from remaining numerator
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// when denominator is not greater.
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skip = spu_cmpgt( denomShifted, numer );
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newNum = spu_sub( numer, denomShifted );
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// If denominator is greater, next shift is one more, otherwise
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// next shift is number of leading zeros of remaining numerator.
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numerZeros = spu_sel( spu_cntlz( newNum ), numerZeros, skip );
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shift = (vec_int4)spu_sub( skip, numerZeros );
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oneShifted = spu_rlmask( oneLeft, shift );
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denomShifted = spu_rlmask( denomLeft, shift );
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quot = spu_sel( newQuot, quot, skip );
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numer = spu_sel( newNum, numer, spu_orc(skip,cont) );
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}
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while ( anyCont );
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res.quot = quot;
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res.rem = numer;
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return res;
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}
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#endif
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