OpenCL:使用struct作为内核参数 [英] OpenCL: using struct as kernel argument

问题描述

我可以使用struct作为OpenCL内核参数吗?

Can I use struct as OpenCL kernel argument?

我想在NVIDIA OpenCL 1.2(NVIDIA驱动程序352.39)中使用结构类型作为OpenCL内核参数

I want to use struct type as OpenCL kernel argument in NVIDIA OpenCL 1.2 (NVIDIA driver 352.39)

我尝试过，但是会导致CL_OUT_OF_RESOURCE错误.

I tried, but it makes CL_OUT_OF_RESOURCE error.

我的代码有什么问题?

[用于结构定义]

/* struct type definition */
typedef struct _st_foo
{
    int aaa;
    int bbb;
     .....
    int zzz;
}st_foo;      // st_foo doesn't have any pointer members

[主机代码]

/* OpenCL initalize... */

st_foo stVar;

cl_mem cm_buffer;
cm_buffer = clCreateBuffer(cxContext, CL_MEM_READ_ONLY, sizeof(st_foo), NULL, NULL);
clSetKernelArg(ckKernel, 0, sizeof(cl_mem), (void*)&cm_buffer);
clEnqueueWriteBuffer(cqueue, cm_buffer, CL_TRUE, 0, sizeof(st_foo), &stVar, 0, NULL, NULL);

[内核代码]

__kernel void testfunction(__global const st_foo *stVar)
{
    printf("stVar->aaa=%d\n", stVar->aaa);
}

推荐答案

如果不使用OpenCL数据类型，则在OpenCL中声明结构是不安全的.而且，对齐可能是一个问题，迫使主机/设备编译器中的数据包对齐.

It is not safe to declare structs in OpenCL if you are not using the OpenCL datatypes. And also, alignment may be an issue, force a packet alignment in the Host/Device compiler.

您应将结构声明为:

[主持人]

typedef struct __attribute__ ((packed)) _st_foo
{
    cl_int aaa;
    cl_int bbb;
     .....
    cl_int zzz;
}st_foo;

[设备]

typedef struct __attribute__ ((packed)) _st_foo
{
    int aaa;
    int bbb;
     .....
    int zzz;
};

另外，如果只需要一个参数而不是结构数组，则只需将其传递为:

Aditionally, if you just want a single parameter, not an array of structs, then just pass it in as:

clSetKernelArg(ckKernel, 0, sizeof(mystruct), mystruct);

这篇关于OpenCL:使用struct作为内核参数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！