Re: [PATCH v2 4/7] exec: Use const alias for TARGET_PAGE_BITS_VARY

[Richard Henderson]

On 10/25/19 10:51 AM, Peter Maydell wrote:
>> + * We want to declare the "target_page" variable as const, which tells
>> + * the compiler that it can cache any value that it reads across calls.
>> + * This avoids multiple assertions and multiple reads within any one user.
>> + *
>> + * This works because we initialize the target_page data very early, in a
>> + * location far removed from the functions that require the final results.
> 
> I have to say that this feels like a worryingly large amount
> of magic. Is this actually guaranteed to work by the compiler?

Yes.


r~