1 | /* |
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2 | * Copyright (c) 2017 International Characters. |
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3 | * This software is licensed to the public under the Open Software License 3.0. |
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4 | */ |
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5 | #ifndef SWIZZLE_H |
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6 | #define SWIZZLE_H |
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7 | |
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8 | #include "kernel.h" |
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9 | namespace IDISA { class IDISA_Builder; } |
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10 | |
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11 | |
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12 | // The SwizzleGenerator class creates a kernel that transforms a set of bit streams into a swizzled form. |
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13 | // In swizzled form, one "swizzle field" each from a set of streams are grouped together to be processed |
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14 | // as a unit using SIMD operations. For example, for a swizzle field width of 64 and a block size of 256, |
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15 | // 4 streams are swizzled together to be operated on as a group. The ratio of the block size to the |
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16 | // swizzle field size is known as the swizzle factor, in this case 4. |
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17 | |
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18 | // Swizzled form is convenient for performing sequential operations on parallel sets of streams, |
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19 | // such as compression of each swizzle field by known counts, or stitching together known numbers |
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20 | // of bits from two different sources. |
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21 | |
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22 | // Any number of bit streams may be swizzled together. However, the outputSets are always |
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23 | // grouped together in multiples of the swizzle factor. If the bit stream count is not |
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24 | // an exact multiple of the swizzle factor, null streams (all zero bits) are added for |
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25 | // each swizzle group. |
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26 | |
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27 | // The input streams may come from any number of parallel input sets, each of the same size. |
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28 | // The number of inputSets defaults to 1. |
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29 | |
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30 | // The output streams may be separated in a number of output sets. However, output streams |
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31 | // sets must be a multiple of the swizzle factor size. |
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32 | |
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33 | // For example: consider the following 4 streams (32 bits each) |
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34 | // Stream 1: abcdef00 ghi00000 jk000000 lmnop000 |
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35 | // Stream 2: qrstuv00 wxy00000 z1000000 23456000 |
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36 | // Stream 3: ABCDEF00 GHI00000 JK000000 LMNOP000 |
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37 | // Stream 4: QRSTUV00 WZY00000 Z1000000 23456000 |
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38 | // |
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39 | // The swizzled output using a field width of 8 produces the following swizzles. |
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40 | // |
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41 | // Swizzle 1: abcdef00 qrstuv00 ABCDEF00 QRSTUV00 |
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42 | // Swizzle 2: ghi00000 wxy00000 GHI00000 WZY00000 |
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43 | // Swizzle 3: jk000000 z1000000 JK000000 Z1000000 |
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44 | // Swizzle 4: lmnop000 23456000 LMNOP000 23456000 |
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45 | // |
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46 | // Now it might be convenient to compress all fields of swizzle 1 by 2, all fields of swizzle 2 by 5 |
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47 | // and so on. |
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48 | // |
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49 | namespace kernel { |
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50 | |
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51 | class SwizzleGenerator : public BlockOrientedKernel { |
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52 | public: |
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53 | |
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54 | SwizzleGenerator(IDISA::IDISA_Builder * iBuilder, unsigned bitStreamCount, unsigned outputSets = 1, unsigned inputSets = 1, unsigned fieldWidth = 64); |
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55 | |
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56 | protected: |
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57 | |
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58 | void generateDoBlockMethod() override; |
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59 | |
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60 | private: |
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61 | const unsigned mBitStreamCount; |
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62 | const unsigned mFieldWidth; |
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63 | const unsigned mSwizzleFactor; |
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64 | const unsigned mInputSets; |
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65 | const unsigned mOutputSets; |
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66 | }; |
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67 | |
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68 | } |
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69 | |
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70 | #endif |
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71 | |
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