1 | /* |
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2 | (C) Copyright 2001,2006, |
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3 | International Business Machines Corporation, |
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4 | Sony Computer Entertainment, Incorporated, |
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5 | Toshiba Corporation, |
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6 | |
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7 | All rights reserved. |
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8 | |
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9 | Redistribution and use in source and binary forms, with or without |
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10 | modification, are permitted provided that the following conditions are met: |
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11 | |
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12 | * Redistributions of source code must retain the above copyright notice, |
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13 | this list of conditions and the following disclaimer. |
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14 | * Redistributions in binary form must reproduce the above copyright |
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15 | notice, this list of conditions and the following disclaimer in the |
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16 | documentation and/or other materials provided with the distribution. |
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17 | * Neither the names of the copyright holders nor the names of their |
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18 | contributors may be used to endorse or promote products derived from this |
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19 | software without specific prior written permission. |
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20 | |
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21 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
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22 | IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
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23 | TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A |
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24 | PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER |
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25 | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
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26 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
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27 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
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28 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
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29 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
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30 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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31 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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32 | */ |
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33 | #ifndef _ROUND_H_ |
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34 | #define _ROUND_H_ 1 |
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35 | |
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36 | #include <spu_intrinsics.h> |
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37 | #include "headers/vec_literal.h" |
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38 | |
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39 | /* Round the input to the nearest integer, rounding halfway |
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40 | * cases away from zero. |
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41 | */ |
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42 | static __inline double _round(double x) |
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43 | { |
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44 | vec_uchar16 splat_hi = VEC_LITERAL(vec_uchar16, 0,1,2,3,0,1,2,3, 8,9,10,11, 8,9,10,11); |
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45 | vec_int4 exp, shift; |
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46 | vec_uint4 sign = VEC_LITERAL(vec_uint4, 0x80000000, 0, 0x80000000, 0); |
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47 | vec_uint4 or_mask, and_mask, mask, addend; |
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48 | vec_double2 in, in_hi, out; |
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49 | |
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50 | in = spu_promote(x, 0); |
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51 | |
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52 | /* Add 0.5 (fixed precision to eliminate rounding issues) |
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53 | */ |
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54 | in_hi = spu_shuffle(in, in, splat_hi); |
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55 | exp = spu_and(spu_rlmask((vec_int4)in_hi, -20), 0x7FF); |
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56 | |
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57 | shift = spu_sub(VEC_LITERAL(vec_int4, 1022, 1043, 1022, 1043), exp); |
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58 | |
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59 | addend = spu_and(spu_rlmask(VEC_LITERAL(vec_uint4, 0x100000, 0x80000000, |
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60 | 0x100000, 0x80000000), shift), |
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61 | spu_cmpgt((vec_uint4)spu_add(shift, -1), -33)); |
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62 | |
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63 | in = (vec_double2)spu_addx((vec_uint4)in, addend, |
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64 | spu_rlqwbyte(spu_genc((vec_uint4)in, addend), 4)); |
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65 | |
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66 | /* Truncate the result. |
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67 | */ |
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68 | in_hi = spu_shuffle(in, in, splat_hi); |
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69 | exp = spu_and(spu_rlmask((vec_int4)in_hi, -20), 0x7FF); |
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70 | |
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71 | shift = spu_sub(VEC_LITERAL(vec_int4, 1023, 1043, 1023, 1043), exp); |
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72 | or_mask = spu_andc(spu_cmpgt(shift, 0), sign); |
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73 | |
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74 | |
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75 | and_mask = spu_rlmask(VEC_LITERAL(vec_uint4, 0xFFFFF, -1, 0xFFFFF, -1), |
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76 | shift); |
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77 | mask = spu_or(spu_and(and_mask, spu_cmpgt(shift, -31)), or_mask); |
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78 | |
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79 | /* Apply the mask and return the result. |
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80 | */ |
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81 | out = spu_andc(in, (vec_double2)(mask)); |
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82 | |
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83 | return (spu_extract(out, 0)); |
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84 | } |
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85 | #endif /* _ROUND_H_ */ |
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