import opencl_course source for a start

opencl/parallel_primitives/kernels/PrefixScanKernels.cl

@@ -0,0 +1,154 @@
+/*
+Copyright (c) 2012 Advanced Micro Devices, Inc.  
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. 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.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+//Originally written by Takahiro Harada
+
+
+typedef unsigned int u32;
+#define GET_GROUP_IDX get_group_id(0)
+#define GET_LOCAL_IDX get_local_id(0)
+#define GET_GLOBAL_IDX get_global_id(0)
+#define GET_GROUP_SIZE get_local_size(0)
+#define GROUP_LDS_BARRIER barrier(CLK_LOCAL_MEM_FENCE)
+
+// takahiro end
+#define WG_SIZE 128 
+#define m_numElems x
+#define m_numBlocks y
+#define m_numScanBlocks z
+
+/*typedef struct
+{
+	uint m_numElems;
+	uint m_numBlocks;
+	uint m_numScanBlocks;
+	uint m_padding[1];
+} ConstBuffer;
+*/
+
+u32 ScanExclusive(__local u32* data, u32 n, int lIdx, int lSize)
+{
+	u32 blocksum;
+    int offset = 1;
+    for(int nActive=n>>1; nActive>0; nActive>>=1, offset<<=1)
+    {
+        GROUP_LDS_BARRIER;
+        for(int iIdx=lIdx; iIdx<nActive; iIdx+=lSize)
+        {
+            int ai = offset*(2*iIdx+1)-1;
+            int bi = offset*(2*iIdx+2)-1;
+            data[bi] += data[ai];
+        }
+	}
+
+    GROUP_LDS_BARRIER;
+
+    if( lIdx == 0 )
+	{
+		blocksum = data[ n-1 ];
+        data[ n-1 ] = 0;
+	}
+
+	GROUP_LDS_BARRIER;
+
+	offset >>= 1;
+    for(int nActive=1; nActive<n; nActive<<=1, offset>>=1 )
+    {
+        GROUP_LDS_BARRIER;
+        for( int iIdx = lIdx; iIdx<nActive; iIdx += lSize )
+        {
+            int ai = offset*(2*iIdx+1)-1;
+            int bi = offset*(2*iIdx+2)-1;
+            u32 temp = data[ai];
+            data[ai] = data[bi];
+            data[bi] += temp;
+        }
+	}
+	GROUP_LDS_BARRIER;
+
+	return blocksum;
+}
+
+__attribute__((reqd_work_group_size(WG_SIZE,1,1)))
+__kernel
+void LocalScanKernel(__global u32* dst, __global u32 *src, __global u32 *sumBuffer,
+		uint4 cb)
+{
+	__local u32 ldsData[WG_SIZE*2];
+
+	int gIdx = GET_GLOBAL_IDX;
+	int lIdx = GET_LOCAL_IDX;
+
+	ldsData[2*lIdx]     = ( 2*gIdx < cb.m_numElems )? src[2*gIdx]: 0;
+	ldsData[2*lIdx + 1] = ( 2*gIdx+1 < cb.m_numElems )? src[2*gIdx + 1]: 0;
+
+	u32 sum = ScanExclusive(ldsData, WG_SIZE*2, GET_LOCAL_IDX, GET_GROUP_SIZE);
+
+	if( lIdx == 0 ) sumBuffer[GET_GROUP_IDX] = sum;
+
+	if( (2*gIdx) < cb.m_numElems )
+    {
+        dst[2*gIdx]     = ldsData[2*lIdx];
+	}
+	if( (2*gIdx + 1) < cb.m_numElems )
+	{
+        dst[2*gIdx + 1] = ldsData[2*lIdx + 1];
+    }
+}
+
+__attribute__((reqd_work_group_size(WG_SIZE,1,1)))
+__kernel
+void AddOffsetKernel(__global u32 *dst, __global u32 *blockSum, uint4 cb)
+{
+	const u32 blockSize = WG_SIZE*2;
+
+	int myIdx = GET_GROUP_IDX+1;
+	int lIdx = GET_LOCAL_IDX;
+
+	u32 iBlockSum = blockSum[myIdx];
+
+	int endValue = min((myIdx+1)*(blockSize), cb.m_numElems);
+	for(int i=myIdx*blockSize+lIdx; i<endValue; i+=GET_GROUP_SIZE)
+	{
+		dst[i] += iBlockSum;
+	}
+}
+
+__attribute__((reqd_work_group_size(WG_SIZE,1,1)))
+__kernel
+void TopLevelScanKernel(__global u32* dst, uint4 cb)
+{
+	__local u32 ldsData[2048];
+	int gIdx = GET_GLOBAL_IDX;
+	int lIdx = GET_LOCAL_IDX;
+	int lSize = GET_GROUP_SIZE;
+
+	for(int i=lIdx; i<cb.m_numScanBlocks; i+=lSize )
+	{
+		ldsData[i] = (i<cb.m_numBlocks)? dst[i]:0;
+	}
+
+	GROUP_LDS_BARRIER;
+
+	u32 sum = ScanExclusive(ldsData, cb.m_numScanBlocks, GET_LOCAL_IDX, GET_GROUP_SIZE);
+
+	for(int i=lIdx; i<cb.m_numBlocks; i+=lSize )
+	{
+		dst[i] = ldsData[i];
+	}
+
+	if( gIdx == 0 )
+	{
+		dst[cb.m_numBlocks] = sum;
+	}
+}