kupl_memcpy2d

Interface Definition

int kupl_memcpy2d(void *dst, size_t dpitch, const void *src, size_t spitch, size_t width, size_t height);

• The maximum width, height, and transfer interval supported by kupl_memcpy2d cannot exceed UINT32_MAX. That is, the maximum values of width, spitch-width, dpitch-width, and height are UINT32_MAX.
• The following conditions must be met: spitch × height < actual size of the memory pointed to by src, and dpitch × height < actual size of the memory pointed to by dst.

Environment Variables

KUPL uses KUPL_MEMCPY_MT_THRESHOLD and KUPL_SDMA_MEMCPY_THRESHOLD to determine the packet size thresholds for the multi-thread memcpy capability and the SDMA memcpy capability, respectively. By default, the multi-thread memcpy threshold is 512 KB, and the SDMA memcpy threshold is 2 MB.

kupl_memcpy2d supports three methods: single-thread glibc memcpy, SDMA memcpy, and multi-thread memcpy. If SDMA is enabled in the environment, determine a memcpy method based on KUPL_SDMA_MEMCPY_THRESHOLD. Data packets smaller than this threshold use glibc memcpy; otherwise, SDMA memcpy is utilized. Similarly, if SDMA is disabled, use KUPL_MEMCPY_MT_THRESHOLD to determine a memcpy method. Data packets smaller than this threshold use glibc memcpy; otherwise, multi-thread memcpy is utilized.

You can define the thresholds for multi-thread memcpy and SDMA memcpy by configuring KUPL_MEMCPY_MT_THRESHOLD and KUPL_SDMA_MEMCPY_THRESHOLD. These configurations are also used by the kupl_memcpy interface to determine the optimal memcpy method.

Parameters

Return Value

• Success: KUPL_OK
• Failure: KUPL_ERROR

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

#include <stdio.h> 
#include <stdlib.h>
#include <assert.h>
#include "kupl.h" 

int main() 
{ 
    int len = 65536; 
    double *src = (double *)kupl_malloc(KUPL_MEM_DEFAULT, len);
    double *dest = (double *)kupl_malloc(KUPL_MEM_DEFAULT, len);
    if (src == nullptr || dest == nullptr) {
        goto error;
    }
    for (int i = 0; i < len / sizeof(double); i++) {
        src[i] = i ;
        dest[i] = 0;
    }
    int height = 2, width = 200;
    int spitch = 300, dpitch = 400;
    int ret = kupl_memcpy2d(dest, dpitch, src, spitch, width, height);
    assert(ret == KUPL_OK);
error:
    kupl_free(KUPL_MEM_DEFAULT, src);
    kupl_free(KUPL_MEM_DEFAULT, dest); 
    return 0; 
}

• The preceding example demonstrates the 2D memory copy process.
• The kupl_memcpy2d function copies the content in the src array to the dest array. The offset for each width data extracted from the src position is 300.
• The offset for each width data stored at the dest position is 400.
• The width and height of the copied data are 200 and 2, respectively.