[Bug target/105429] Unnecessary moves generated with _mm_crc32_u64

[ubizjak at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105429

--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
The intrinsic is defined as:

unsinged __int64 _mm_crc32_u64( unsinged __int64 crc, unsigned __int64 data )

and the unnecessary move is in fact zero-extend:

        movl    %eax, %eax      # 16    [c=1 l=2]  *zero_extendsidi2/3

You probably want:

uint32_t crc(uint64_t current, const uint8_t *buffer, size_t size) {
    for(size_t i = 0; i < size; i++)
        current = _mm_crc32_u64(current, buffer[i]);
    return current;
}