1/* 2Copyright (c) 2012 Advanced Micro Devices, Inc. 3 4This software is provided 'as-is', without any express or implied warranty. 5In no event will the authors be held liable for any damages arising from the use of this software. 6Permission is granted to anyone to use this software for any purpose, 7including commercial applications, and to alter it and redistribute it freely, 8subject to the following restrictions: 9 101. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 112. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 123. This notice may not be removed or altered from any source distribution. 13*/ 14//Originally written by Takahiro Harada 15 16 17typedef unsigned int u32; 18#define GET_GROUP_IDX get_group_id(0) 19#define GET_LOCAL_IDX get_local_id(0) 20#define GET_GLOBAL_IDX get_global_id(0) 21#define GET_GROUP_SIZE get_local_size(0) 22#define GROUP_LDS_BARRIER barrier(CLK_LOCAL_MEM_FENCE) 23 24// takahiro end 25#define WG_SIZE 128 26#define m_numElems x 27#define m_numBlocks y 28#define m_numScanBlocks z 29 30/*typedef struct 31{ 32 uint m_numElems; 33 uint m_numBlocks; 34 uint m_numScanBlocks; 35 uint m_padding[1]; 36} ConstBuffer; 37*/ 38 39u32 ScanExclusive(__local u32* data, u32 n, int lIdx, int lSize) 40{ 41 u32 blocksum; 42 int offset = 1; 43 for(int nActive=n>>1; nActive>0; nActive>>=1, offset<<=1) 44 { 45 GROUP_LDS_BARRIER; 46 for(int iIdx=lIdx; iIdx<nActive; iIdx+=lSize) 47 { 48 int ai = offset*(2*iIdx+1)-1; 49 int bi = offset*(2*iIdx+2)-1; 50 data[bi] += data[ai]; 51 } 52 } 53 54 GROUP_LDS_BARRIER; 55 56 if( lIdx == 0 ) 57 { 58 blocksum = data[ n-1 ]; 59 data[ n-1 ] = 0; 60 } 61 62 GROUP_LDS_BARRIER; 63 64 offset >>= 1; 65 for(int nActive=1; nActive<n; nActive<<=1, offset>>=1 ) 66 { 67 GROUP_LDS_BARRIER; 68 for( int iIdx = lIdx; iIdx<nActive; iIdx += lSize ) 69 { 70 int ai = offset*(2*iIdx+1)-1; 71 int bi = offset*(2*iIdx+2)-1; 72 u32 temp = data[ai]; 73 data[ai] = data[bi]; 74 data[bi] += temp; 75 } 76 } 77 GROUP_LDS_BARRIER; 78 79 return blocksum; 80} 81 82__attribute__((reqd_work_group_size(WG_SIZE,1,1))) 83__kernel 84void LocalScanKernel(__global u32* dst, __global u32 *src, __global u32 *sumBuffer, 85 uint4 cb) 86{ 87 __local u32 ldsData[WG_SIZE*2]; 88 89 int gIdx = GET_GLOBAL_IDX; 90 int lIdx = GET_LOCAL_IDX; 91 92 ldsData[2*lIdx] = ( 2*gIdx < cb.m_numElems )? src[2*gIdx]: 0; 93 ldsData[2*lIdx + 1] = ( 2*gIdx+1 < cb.m_numElems )? src[2*gIdx + 1]: 0; 94 95 u32 sum = ScanExclusive(ldsData, WG_SIZE*2, GET_LOCAL_IDX, GET_GROUP_SIZE); 96 97 if( lIdx == 0 ) sumBuffer[GET_GROUP_IDX] = sum; 98 99 if( (2*gIdx) < cb.m_numElems ) 100 { 101 dst[2*gIdx] = ldsData[2*lIdx]; 102 } 103 if( (2*gIdx + 1) < cb.m_numElems ) 104 { 105 dst[2*gIdx + 1] = ldsData[2*lIdx + 1]; 106 } 107} 108 109__attribute__((reqd_work_group_size(WG_SIZE,1,1))) 110__kernel 111void AddOffsetKernel(__global u32 *dst, __global u32 *blockSum, uint4 cb) 112{ 113 const u32 blockSize = WG_SIZE*2; 114 115 int myIdx = GET_GROUP_IDX+1; 116 int lIdx = GET_LOCAL_IDX; 117 118 u32 iBlockSum = blockSum[myIdx]; 119 120 int endValue = min((myIdx+1)*(blockSize), cb.m_numElems); 121 for(int i=myIdx*blockSize+lIdx; i<endValue; i+=GET_GROUP_SIZE) 122 { 123 dst[i] += iBlockSum; 124 } 125} 126 127__attribute__((reqd_work_group_size(WG_SIZE,1,1))) 128__kernel 129void TopLevelScanKernel(__global u32* dst, uint4 cb) 130{ 131 __local u32 ldsData[2048]; 132 int gIdx = GET_GLOBAL_IDX; 133 int lIdx = GET_LOCAL_IDX; 134 int lSize = GET_GROUP_SIZE; 135 136 for(int i=lIdx; i<cb.m_numScanBlocks; i+=lSize ) 137 { 138 ldsData[i] = (i<cb.m_numBlocks)? dst[i]:0; 139 } 140 141 GROUP_LDS_BARRIER; 142 143 u32 sum = ScanExclusive(ldsData, cb.m_numScanBlocks, GET_LOCAL_IDX, GET_GROUP_SIZE); 144 145 for(int i=lIdx; i<cb.m_numBlocks; i+=lSize ) 146 { 147 dst[i] = ldsData[i]; 148 } 149 150 if( gIdx == 0 ) 151 { 152 dst[cb.m_numBlocks] = sum; 153 } 154} 155