OpenCLAllocator::upload() unnecessary loop slow down the operation (Bug #3488)

Added by Hui Zhao about 11 years ago. Updated about 11 years ago.

Status:	Done	Start date:	2014-01-15
Priority:	Normal	Due date:
Assignee:	Ilya Lavrenov	% Done:	100%
Category:	ocl
Target version:	3.0-alpha
Affected version:	branch 'master' (3.0-dev)	Operating System:	Any
Difficulty:	Easy	HW Platform:	Any
Pull request:	https://github.com/Itseez/opencv/pull/2165

Description

Puzzled on the strange slowness for `Mat.copyTo(UMat)`. By checking out the code found

core\src\ocl.cpp, around line 3539 with unnecessary crc looping. Please fix it. It does slow down the operation significantly(x10 tested on 60x30MByte of data). Thank you.

        if( iscontinuous )
        {
            int crc = 0;
            for( size_t i = 0; i < total; i++ )
                crc ^= ((uchar*)srcptr)[i];
            CV_Assert( clEnqueueWriteBuffer(q, (cl_mem)u->handle,
                CL_TRUE, dstrawofs, total, srcptr, 0, 0, 0) >= 0 );
        }