Re: [Qemu-devel] [PATCH] savevm.c: Fix compilation error on 32bit host.

[Michael Tokarev]

On 15.08.2012 13:10, Evgeny Voevodin wrote:
> Casting of 0x0101010101010101ULL to long will truncate it to 32
> bits on 32bit hosts, and won't truncate on 64bit hosts.
> 
> Signed-off-by: Evgeny Voevodin <address@hidden>
> ---
>  savevm.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/savevm.c b/savevm.c
> index 0ea10c9..9ab4d83 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -2473,7 +2473,7 @@ int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t 
> *new_buf, int slen,
>          /* word at a time for speed, use of 32-bit long okay */
>          if (!res) {
>              /* truncation to 32-bit long okay */
> -            long mask = 0x0101010101010101ULL;
> +            long mask = (long)0x0101010101010101ULL;
>              while (i < slen) {
>                  xor = *(long *)(old_buf + i) ^ *(long *)(new_buf + i);
>                  if ((xor - mask) & ~xor & (mask << 7)) {

Um, how it is ugly... Can't we use unsigned types for all this stuff?
Including slen too - the function parameter...

Thanks,

/mjt