Re: [U-Boot] [PATCH v2] lib:crc32: Allow setting of the initial crc32 value

Hi Marek,

On Wednesday, May 07, 2014 at 08:10:20 AM, Lukasz Majewski wrote:

[...]

...

--- a/lib/crc32.c +++ b/lib/crc32.c @@ -255,9 +255,12 @@ uint32_t ZEXPORT crc32_wd (uint32_t crc, void crc32_wd_buf(const unsigned char *input, unsigned int ilen, unsigned char *output, unsigned int chunk_sz) {

• uint32_t crc;

• uint32_t crc = 0;

• crc = crc32_wd(0, input, ilen, chunk_sz);

• if (*output)

• memcpy(&crc, output, sizeof(crc));
  

Won't some sort of put_unaligned() work here ? The $crc is uint32_t afterall, so it might be a jiff faster.

We are concerned here with the use case of copying 4 bytes from unaligned buffer defined on some architectures.

I suppose, that the performance would be the same for both. However, since memcpy() is already used in this function, I would prefer to use it here.

Please correct me if I'm wrong.

...

• crc = crc32_wd(crc, input, ilen, chunk_sz); crc = htonl(crc); memcpy(output, &crc, sizeof(crc));

}

Best regards, Marek Vasut