Bolt SAMPLE CODE CONTEST : Radix sort

examples/CMakeLists.txt.in

@@ -180,6 +180,7 @@ endif( )
 find_package( Bolt REQUIRED )
 
 add_subdirectory( DeviceVector )
+add_subdirectory( RadixSort )
 add_subdirectory( Scan )
 add_subdirectory( Sort )
 add_subdirectory( StdDev )

examples/RadixSort/CMakeLists.txt

@@ -0,0 +1,46 @@
+############################################################################                                                                                     
+#   Copyright 2012 - 2013 Advanced Micro Devices, Inc.                                     
+#                                                                                    
+#   Licensed under the Apache License, Version 2.0 (the "License");   
+#   you may not use this file except in compliance with the License.                 
+#   You may obtain a copy of the License at                                          
+#                                                                                    
+#       http://www.apache.org/licenses/LICENSE-2.0                      
+#                                                                                    
+#   Unless required by applicable law or agreed to in writing, software              
+#   distributed under the License is distributed on an "AS IS" BASIS,              
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.         
+#   See the License for the specific language governing permissions and              
+#   limitations under the License.                                                   
+
+############################################################################                                                                                     
+
+# List the names of common files to compile across all platforms
+set( clBolt.Example.RadixSort.Source RadixSort.cpp )
+set( clBolt.Example.RadixSort.Headers   ${BOLT_INCLUDE_DIRS}/bolt/cl/count.h ${BOLT_INCLUDE_DIRS}/bolt/cl/detail/count.inl
+                                        ${BOLT_INCLUDE_DIRS}/bolt/cl/device_vector.h
+                                        ${BOLT_INCLUDE_DIRS}/bolt/cl/scan.h ${BOLT_INCLUDE_DIRS}/bolt/cl/detail/scan.inl
+                                        ${BOLT_INCLUDE_DIRS}/bolt/cl/scatter.h ${BOLT_INCLUDE_DIRS}/bolt/cl/detail/scatter.inl
+                                        ${BOLT_INCLUDE_DIRS}/bolt/cl/transform.h ${BOLT_INCLUDE_DIRS}/bolt/cl/detail/transform.inl )
+
+set( clBolt.Example.RadixSort.Files ${clBolt.Example.RadixSort.Source} ${clBolt.Example.RadixSort.Headers} )
+
+# Include headers files
+include_directories( ${BOLT_INCLUDE_DIRS} ${OPENCL_INCLUDE_DIRS} )
+
+add_executable( clBolt.Example.RadixSort ${clBolt.Example.RadixSort.Files} )
+if(BUILD_TBB)
+    target_link_libraries( clBolt.Example.RadixSort ${BOLT_LIBRARIES} ${OPENCL_LIBRARIES} ${GTEST_LIBRARIES} ${Boost_LIBRARIES}  ${TBB_LIBRARIES} )
+else (BUILD_TBB)
+    target_link_libraries( clBolt.Example.RadixSort ${BOLT_LIBRARIES} ${OPENCL_LIBRARIES} ${GTEST_LIBRARIES} ${Boost_LIBRARIES}  )
+endif()
+
+set_target_properties( clBolt.Example.RadixSort PROPERTIES VERSION ${Examples_VERSION} )
+set_target_properties( clBolt.Example.RadixSort PROPERTIES RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/staging" )
+
+# CPack configuration; include the executable into the package
+install( TARGETS clBolt.Example.RadixSort
+	RUNTIME DESTINATION ${BIN_DIR}
+	LIBRARY DESTINATION ${LIB_DIR}
+	ARCHIVE DESTINATION ${LIB_DIR}
+	)

examples/RadixSort/RadixSort.cpp

@@ -0,0 +1,185 @@
+/***************************************************************************
+*   Copyright 2012 - 2013 Advanced Micro Devices, Inc.
+*
+*   Licensed under the Apache License, Version 2.0 (the "License");
+*   you may not use this file except in compliance with the License.
+*   You may obtain a copy of the License at
+*
+*       http://www.apache.org/licenses/LICENSE-2.0
+*
+*   Unless required by applicable law or agreed to in writing, software
+*   distributed under the License is distributed on an "AS IS" BASIS,
+*   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+*   See the License for the specific language governing permissions and
+*   limitations under the License.
+
+***************************************************************************/
+
+#include <bolt/cl/count.h>
+#include <bolt/cl/device_vector.h>
+#include <bolt/cl/scan.h>
+#include <bolt/cl/scatter.h>
+#include <bolt/cl/transform.h>
+
+#include <iostream>
+#include <vector>
+#include <numeric>
+
+const int BITS_IN_UNSIGNED = (8*sizeof(unsigned));
+
+template <typename T>
+void CheckAscending(T &input, size_t length)
+{
+    size_t index;
+    for( index = 0; index < input.size( ) -1; ++index )
+    {
+        if(input[index] <= input[index+1])
+            continue;
+        else
+            break;
+    }
+    if(index == (length-1))
+    {
+        std::cout << "PASSED....\n";
+    }
+    else
+    {
+        std::cout << "FAILED....\n";
+    }
+}
+
+// Serial version of Radix Sort
+void SerialRadixSort (const std::vector<unsigned> &input, size_t length, std::vector<unsigned> &answerSerial)
+{
+    std::vector<unsigned> vInput(input.begin(), input.end());
+    std::vector<unsigned> vBuffer0(length);
+    std::vector<unsigned> vBuffer1(length);
+
+    for (int iter = 0; iter < BITS_IN_UNSIGNED; iter++)
+    {
+        int iOffsetB0 = 0;
+        int iOffsetB1 = 0;
+
+        // Separate 0s and 1s to separate buffers
+        for (int i = 0; i < length; i++)
+        {
+            if ((vInput[i] & (1<<iter)) == 0) // 0s
+                vBuffer0[iOffsetB0++] = vInput[i];
+            else // 1s
+                vBuffer1[iOffsetB1++] = vInput[i];
+        }
+        // Copy 0s to the beginning of the vInput
+        std::vector<unsigned>::iterator vInputNext = std::copy(vBuffer0.begin(), vBuffer0.begin() + iOffsetB0, vInput.begin());
+        // Copy 1s to after 0s we just copied
+        std::copy(vBuffer1.begin(), vBuffer1.begin() + iOffsetB1, vInputNext);
+    }
+
+    // Copy the answer 
+    std::copy(vInput.begin(), vInput.end(), back_inserter(answerSerial));
+}
+
+// Functor for checking whether bit is 0 or 1
+BOLT_FUNCTOR(find_zeros,
+struct find_zeros
+{
+    unsigned iMask;
+
+    find_zeros (unsigned iter) { iMask = 1 << iter;};
+
+    bool operator()(const unsigned &x) const {return (x & iMask) == 0;}
+};
+);
+
+BOLT_FUNCTOR(find_ones,
+struct find_ones
+{
+    unsigned iMask;
+
+    find_ones (unsigned iter) { iMask = 1 << iter;};
+
+    bool operator()(const unsigned &x) const {return (x & iMask) != 0;}
+};
+);
+
+// Bolt version of Radix Sort
+void BoltRadixSort (const std::vector<unsigned> &input, size_t length, std::vector<unsigned> &answerBolt)
+{
+    bolt::cl::device_vector<unsigned> dvInput( input.begin(), input.end());
+    bolt::cl::device_vector<unsigned> dvBuffer(length);
+    bolt::cl::device_vector<unsigned> dvMaskedVals(length);
+    bolt::cl::device_vector<unsigned> dvOffsetVals(length);
+
+    for (int iter = 0; iter < BITS_IN_UNSIGNED; iter += 2)
+    {
+        // iter
+        // Separate 0s first
+        bolt::cl::transform(dvInput.begin(), dvInput.end(), dvMaskedVals.begin(), find_zeros(iter)); // Find elements with 0's, in parallel
+        bolt::cl::exclusive_scan(dvMaskedVals.begin(), dvMaskedVals.end(), dvOffsetVals.begin()); // Figure out where in the buffer to copy to, in parallel
+        bolt::cl::scatter_if(dvInput.begin(), dvInput.end(), dvOffsetVals.begin(), dvMaskedVals.begin(), dvBuffer.begin()); // Copy all the values to the buffer in parallel
+
+        // And then, separate 1s
+        int count = bolt::cl::count(dvMaskedVals.begin(), dvMaskedVals.end(), 1); // Count how many elements with 0's we already processed
+        bolt::cl::transform(dvInput.begin(), dvInput.end(), dvMaskedVals.begin(), find_ones(iter)); // Find elements with 1's, in parallel
+        bolt::cl::exclusive_scan(dvMaskedVals.begin(), dvMaskedVals.end(), dvOffsetVals.begin(), count); // Figure out where in the buffer to copy to, in parallel
+        bolt::cl::scatter_if(dvInput.begin(), dvInput.end(), dvOffsetVals.begin(), dvMaskedVals.begin(), dvBuffer.begin()); // Copy all the values to the buffer in parallel
+
+        // iter + 1
+        // In order to avoid unnecessary copy operation, perfrom (iter+1)'th iteration in the same loop
+        // Separate 0s first
+        bolt::cl::transform(dvBuffer.begin(), dvBuffer.end(), dvMaskedVals.begin(), find_zeros(iter+1)); // Find elements with 0's first, in parallel
+        bolt::cl::exclusive_scan(dvMaskedVals.begin(), dvMaskedVals.end(), dvOffsetVals.begin()); // Figure out where in the buffer to copy to, in parallel
+        bolt::cl::scatter_if(dvBuffer.begin(), dvBuffer.end(), dvOffsetVals.begin(), dvMaskedVals.begin(), dvInput.begin()); // Copy all the values to the buffer in parallel
+
+        // And then, separate 1s
+        count = bolt::cl::count(dvMaskedVals.begin(), dvMaskedVals.end(), 1); // Count how many elements with 0's we already processed
+        bolt::cl::transform(dvBuffer.begin(), dvBuffer.end(), dvMaskedVals.begin(), find_ones(iter+1)); // Find elements with 1's, in parallel
+        bolt::cl::exclusive_scan(dvMaskedVals.begin(), dvMaskedVals.end(), dvOffsetVals.begin(), count); // Figure out where in the buffer to copy to, in parallel
+        bolt::cl::scatter_if(dvBuffer.begin(), dvBuffer.end(), dvOffsetVals.begin(), dvMaskedVals.begin(), dvInput.begin()); // Copy all the values to the buffer in parallel
+    }
+
+    // Copy the answer 
+    bolt::cl::device_vector<unsigned>::pointer pData = dvInput.data();
+    std::copy(&pData[0], &pData[length], back_inserter(answerBolt));
+}
+
+int main()
+{
+    std::cout << "\nRadix Sort EXAMPLE \n";
+
+    srand (time(NULL));
+
+    // Prepare 2^10 elements of random unsigned numbers to be sorted
+    size_t length = 1024*1024;
+    std::vector<unsigned> input(length);
+    std::generate(input.begin(), input.end(), rand);
+
+    std::vector<unsigned> answerBolt;
+    std::vector<unsigned> answerSerial;
+
+    // Serial version of Radix Sort
+    std::cout << "\nSorting a vector of " << length << " unsigned integer elements using Serial Radix sort.\n";
+    SerialRadixSort (input, length, answerSerial);
+    CheckAscending (answerSerial, length);
+
+    // Bolt version of Radix Sort
+    std::cout << "\nSorting a vector of " << length << " unsigned integer elements using Bolt Radix sort.\n";
+    BoltRadixSort (input, length, answerBolt);
+    CheckAscending (answerBolt, length);
+
+    // Verify that answerSerial matches answerBolt
+    std::cout << "\nComparing output of Serial Radix sort and Bolt Radix sort.\n";
+    size_t i=0;
+    for (i=0; i<answerSerial.size(); i++)
+    {
+        if (answerSerial[i] != answerBolt[i])
+        {
+            std::cout << "Mismatch!!!" << std::endl;
+            break;
+        }
+    }
+    if (i == answerSerial.size())
+        std::cout << "Serial Radix sort and Bolt Radix sort matched!" << std::endl;
+
+    std::cout << "COMPLETED. ...\n";
+    return 0;
+}