Il 22/08/2013 04:02, Alexey Kardashevskiy ha scritto:
>> Int128 is opaque, please use int128_and. To build the constant you have
>> three choices (from my preferred to IMHO worst):
>>
>> - add a new int128_exts64 function that sign-extends an int64_t
>
> Like this? I am really scared to screw here :)
>
> static inline Int128 int128_exts64(int64_t a)
> {
> return (Int128) { .lo = a, .hi = (a < 0) ? -1 : 0 };
> }
Yes, or just a >> 63.
>> - use int128_neg(int128_make64(TARGET_PAGE_SIZE)) or something like that
>
> Did you actually mean TARGET_PAGE_SIZE-1 (with -1)? I'll better use this
> for now.
it would be either ~(TARGET_PAGE_SIZE-1) or -TARGET_PAGE_SIZE, I think.
>> - add a new int128_make function that takes a low/high pair and use
>> int128_make(TARGET_PAGE_MASK, -1)
>
> I liked this one actually but you called it "worst" :)
It is really the same as #1 but inlined, which is why I called it the worst.
#2 is ugly for a different reason, namely because it changes the code
more substantially, from using TARGET_PAGE_MASK pre-patch to
TARGET_PAGE_SIZE post-patch.
Paolo
