| /* -------------------------------------------------------------- */ |
| /* (C)Copyright 2001,2008, */ |
| /* 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 name of IBM Corporation 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. */ |
| /* -------------------------------------------------------------- */ |
| /* PROLOG END TAG zYx */ |
| #ifdef __SPU__ |
| #ifndef _POWD2_H_ |
| #define _POWD2_H_ 1 |
| |
| #include "exp2d2.h" |
| #include "log2d2.h" |
| |
| /* |
| * FUNCTION |
| * vector double _powd2(vector double x, vector double y) |
| * |
| * DESCRIPTION |
| * The _powd2 function computes x raised to the power y for the set of |
| * vectors. The powd2 function is computed as by decomposing |
| * the problem into: |
| * |
| * x^y = 2^(y*log2(x)) |
| * |
| * |
| */ |
| static __inline vector double _powd2(vector double x, vector double y) |
| { |
| vec_uchar16 splat_hi = (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_uint4) { 0x80000000, 0, 0x80000000, 0 }; |
| vec_uint4 or_mask, and_mask, evenmask, intmask; |
| vec_double2 in_hi; |
| vector double signmask = spu_splats(-0.0); |
| vector signed int error = spu_splats(-1); |
| vector double zero = spu_splats(0.0); |
| vector unsigned int y_is_int, y_is_odd, y_is_even; |
| vector unsigned int x_is_neg; |
| vector double xabs, xsign; |
| vector double out; |
| |
| |
| xsign = spu_and(x, signmask); |
| xabs = spu_andc(x, signmask); |
| x_is_neg = (vec_uint4)spu_cmpgt(zero, x); |
| |
| |
| /* First we solve assuming x was non-negative */ |
| out = _exp2d2(spu_mul(y, _log2d2(xabs))); |
| |
| in_hi = spu_shuffle(y, y, splat_hi); |
| exp = spu_and(spu_rlmask((vec_int4)in_hi, -20), 0x7FF); |
| |
| /* Determine if y is an integer */ |
| shift = spu_sub(((vec_int4) { 1023, 1043, 1023, 1043 }), exp); |
| or_mask = spu_andc(spu_cmpgt(shift, 0), sign); |
| and_mask = spu_rlmask(((vec_uint4) { 0xFFFFF, -1, 0xFFFFF, -1 }), shift); |
| intmask = spu_or(spu_and(and_mask, spu_cmpgt(shift, -32)), or_mask); |
| y_is_int = (vec_uint4)spu_cmpeq(y, spu_andc(y, (vec_double2)(intmask))); |
| |
| /* Determine if y is an even integer */ |
| shift = spu_sub(((vec_int4) { 1024, 1044, 1024, 1044 }), exp); |
| or_mask = spu_andc(spu_cmpgt(shift, 0), sign); |
| and_mask = spu_rlmask(((vec_uint4) { 0xFFFFF, -1, 0xFFFFF, -1 }), shift); |
| evenmask = spu_or(spu_and(and_mask, spu_cmpgt(shift, -32)), or_mask); |
| y_is_even = (vec_uint4)spu_cmpeq(y, spu_andc(y, (vec_double2)(evenmask))); |
| |
| y_is_odd = spu_andc(y_is_int, y_is_even); |
| |
| |
| /* Special Cases |
| */ |
| |
| /* x < 0 is only ok when y integer */ |
| out = spu_sel(out, (vec_double2)error, (vec_ullong2)spu_andc(x_is_neg, y_is_int)); |
| |
| /* Preserve the sign of x if y is an odd integer */ |
| out = spu_sel(out, spu_or(out, xsign), (vec_ullong2)y_is_odd); |
| |
| /* x = anything, y = +/- 0, returns 1 */ |
| out = spu_sel(out, spu_splats(1.0), spu_cmpabseq(y, zero)); |
| |
| return(out); |
| } |
| |
| #endif /* _POWD2_H_ */ |
| #endif /* __SPU__ */ |