# HG changeset patch
# User Yuuhi TOMARI <yuhi@cr.ie.u-ryukyu.ac.jp>
# Date 1334145560 -32400
# Node ID 4d6463c84338bbdb5b75d81255249c492875890f

Twice example on OpenCL

diff -r 000000000000 -r 4d6463c84338 twice.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/twice.cc	Wed Apr 11 20:59:20 2012 +0900
@@ -0,0 +1,98 @@
+#include <stdlib.h>
+#include <OpenCL/opencl.h>
+#include <stdio.h>
+
+#define MAX_SOURCE_SIZE (0x100000)
+#define DEFAULT 432
+
+void
+print_data(int *data, int size, const char *title)
+{
+    printf("%s ---\n", title);
+    for ( int i = 0; i < size; i++) {
+        printf("%2d ", data[i]);
+    }
+    printf("\n");
+}
+
+int main(int argc, char *argv[]) {
+
+    cl_platform_id platform_id = NULL;
+    cl_uint ret_num_platforms;
+    cl_device_id device_id = NULL;
+    cl_uint ret_num_devices;
+    cl_context context = NULL;
+    cl_command_queue command_queue = NULL;
+    cl_mem memobj_in, memobj_out, data_count = NULL;
+    cl_program program = NULL;
+    cl_kernel kernel = NULL;
+    size_t kernel_code_size;
+    char *kernel_src_str;
+    cl_int ret;
+    FILE *fp;
+    cl_event ev;
+
+    clGetPlatformIDs(1, &platform_id, &ret_num_platforms);
+    clGetDeviceIDs(platform_id, CL_DEVICE_TYPE_DEFAULT, 1, &device_id, 
+                   &ret_num_devices);
+    context = clCreateContext( NULL, 1, &device_id, NULL, NULL, &ret);
+
+    command_queue = clCreateCommandQueue(context, device_id, 0, &ret);
+    fp = fopen("twice.cl", "r");
+    kernel_src_str = (char*)malloc(MAX_SOURCE_SIZE);
+    kernel_code_size = fread(kernel_src_str, 1, MAX_SOURCE_SIZE, fp);
+    fclose(fp);
+
+    program = clCreateProgramWithSource(context, 1, (const char **)&kernel_src_str,
+                                        (const size_t *)&kernel_code_size, &ret);
+    clBuildProgram(program, 1, &device_id, "", NULL, NULL);
+    kernel = clCreateKernel(program, "twice", &ret);
+
+    int task_array_num;
+    if ( ((task_array_num = atoi(argv[1])) == 0)  || argc != 1 ){
+        // 無効な引数ならデフォルトの値として432を設定
+        task_array_num = DEFAULT;
+    }
+
+    int count,*data,*output_data;
+    data = (int *)malloc(sizeof(int)*task_array_num);
+    output_data = (int *)malloc(sizeof(int)*task_array_num);
+
+    for (count = 0; count < task_array_num ; count++){
+        data[count] = count;
+    }
+
+    //メモリバッファの作成
+    memobj_in = clCreateBuffer(context, CL_MEM_READ_WRITE, sizeof(int)*count, NULL, &ret);
+    memobj_out = clCreateBuffer(context, CL_MEM_READ_WRITE, sizeof(int)*count, NULL, &ret);
+    data_count = clCreateBuffer(context, CL_MEM_READ_WRITE, sizeof(int)*count, NULL, &ret);
+  
+    //メモリバッファに入力データを書き込み
+    ret = clEnqueueWriteBuffer(command_queue, memobj_in, CL_TRUE, 0,
+                               sizeof(int)*count, data, 0, NULL, NULL);
+    ret = clEnqueueWriteBuffer(command_queue, data_count, CL_TRUE, 0,
+                                   sizeof(count), &count, 0, NULL, NULL);
+    
+    print_data(data, count, "before");
+    
+    clSetKernelArg(kernel, 0, sizeof(cl_mem), (void *)&memobj_in);
+    clSetKernelArg(kernel, 1, sizeof(cl_mem), (void *)&memobj_out);
+    clSetKernelArg(kernel, 2, sizeof(cl_mem), (void *)&data_count);
+    ret = clEnqueueTask(command_queue, kernel, 0, NULL, &ev);
+    
+    //メモリバッファから結果を取得
+    ret = clEnqueueReadBuffer(command_queue, memobj_out, CL_TRUE, 0,
+                              sizeof(int)*count, output_data, 1, &ev, NULL);
+        
+    print_data(output_data, count, "after");
+    free(data);
+    free(output_data);
+    clReleaseKernel(kernel);
+    clReleaseProgram(program);
+    clReleaseCommandQueue(command_queue);
+    clReleaseContext(context);
+
+    free(kernel_src_str);
+
+    return 0;
+}
diff -r 000000000000 -r 4d6463c84338 twice.cl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/twice.cl	Wed Apr 11 20:59:20 2012 +0900
@@ -0,0 +1,11 @@
+__kernel void
+twice(__global int *input_data,
+      __global int *output_data,
+      __global int *data_count)
+{
+    int count = *data_count;
+	for (int i = 0; i<count; i++) {
+	    output_data[i] = input_data[i] * 2;
+	}
+        
+}
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