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    SubjectRe: [PATCH] lib/libcrc32c
    Date

    Hi,

    On Tuesday 30 of March 2004 19:32, Clay Haapala wrote:
    > On Fri, 26 Mar 2004, James Morris outgrape:
    > > These need to be rediffed against the latest Linus kernel.
    > >
    > > It may be better to wait until 2.6.5 comes out, so we don't have too
    > > much new stuff going into the -rc kernels.
    > >
    > >
    > > - James
    >
    > Rediffed they are! I see that the digest setkey() api is already part
    > of -rc3, so because this code is a simple "add" and I will be
    > on vacation next week when 2.6.5 might be cut, I am providing the
    > patch now.
    >
    > This patch agains 2.6.5-rc3 kernel code implements the CRC32C
    > algorithm. The routines are based on the same design as the
    > existing CRC32 code. Licensing is intended to be identical (GPL).

    +/*
    + * This is the CRC-32C table
    + * Generated with:
    + * width = 32 bits
    + * poly = 0x1EDC6F41
    + * reflect input bytes = true
    + * reflect output bytes = true
    + */
    +
    +static u32 crc32c_table[256] = {

    Tables are build time generated in case of CRC32 (lib/gen_crc32table.c)
    so you can trade some performance for smaller size of the table.

    [ However I don't know how useful is this. ]

    +/*EXPORT_SYMBOL(crc32c_be);*/
    +
    +#if CRC_BE_BITS == 1
    +u32 attribute((pure))
    +crc32_be(u32 crc, unsigned char const *p, size_t len)
    +{
    + int i;
    + while (len--) {
    + crc ^= *p++ << 24;
    + for (i = 0; i < 8; i++)
    + crc =
    + (crc << 1) ^ ((crc & 0x80000000) ? CRC32C_POLY_BE :
    + 0);
    + }
    + return crc;
    +}
    +#endif

    Is there any reason in adding crc32_be() until it is finished
    (LE version) and/or needed?

    Regards,
    Bartlomiej

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