On 11.09.19 23:52, Richard Henderson wrote:
> On 9/6/19 3:57 AM, David Hildenbrand wrote:
>> + /*
>> + * Our access should not exceed single pages, as we must not report
>> access
>> + * exceptions exceeding the actually copied range (which we don't know
>> at
>> + * this point). We might over-indicate watchpoints within the pages
>> + * (if we ever care, we have to limit processing to a single byte).
>> + */
>> + srca = access_prepare(env, s, len, MMU_DATA_LOAD, ra);
>> + desta = access_prepare(env, d, len, MMU_DATA_STORE, ra);
>> + for (i = 0; i < len; i++) {
>> + const uint8_t v = access_get_byte(env, &srca, i, ra);
>> +
>> + access_set_byte(env, &desta, i, v, ra);
>> if (v == c) {
>> - set_address_zero(env, r1, d + len);
>> + set_address_zero(env, r1, d + i);
>> return 1;
>> }
>
> Worth using memchr + memmove w/ nondestructive overlap?
In theory yes, however, the issue is that we would have multiple
accesses, which is not documented for this instruction. In case the
memory is modified between memchr + memmove by another CPU, we could
have an inconsistent instruction result. Unlikely but possible :)
>
> That said,
> Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
>
> r~
>
--
Thanks,
David / dhildenb
