如何cudaMemcpy由指向设备数组的指针数组指向的主机值Cuda

Question

I am trying to find a way, if it is possible, to copy the values that are pointed by a host array of pointers pts that points to some elements of another host array s ( float2 type). The values that need to be dereferenced from pts with the -> operator are in random positions in the s array.

Is there a way to copy these values pointed by pts without having to use an intermediate host buffer to write the values in it before using cudaMemcpy ? I only came up with a for loop copying one element at a time but isnt this redundant? I use cuda 5.5 Thanks.

Answer 1

If the values you want to copy are in random locations, and you want to copy only those values to the device, you will need to write a separate loop in host code that aggregates those values first into a single contiguous buffer.

You can then copy that buffer using an ordinary approach like cudaMemcpy .