> But in the VLA case, doesn't it instead have precision 4+4X?
> The problem then is that we can't tell at compile time which
> byte that corresponds to. So...
Yes 4 + 4x. I keep getting confused with poly modes :)
In this case we want to extract the bitnum [3 4] = 3 + 4x which
would be in byte 0 for x = 0 or x = 1 and in byte 1 for x = 2, 3 and
so on.
Can't we still make that work somehow? As far as I can tell we're looking
for the byte range to be accessed. It's not like we have a precision or
bitnum of e.g. [3 17] where the access could be anywhere but still a pow2
fraction of BITS_PER_UNIT.
I'm just having trouble writing that down.
What about something like
int factor = BITS_PER_UINT / prec.coeffs[0];
bytenum = force_align_down_and_div (bitnum, prec.coeffs[0]);
bytenum *= factor;
(or a similar thing done manually without helpers) guarded by the
proper condition?
Or do we need something more generic for the factor (i.e. prec.coeffs[0])
is not enough when we have a precision like [8 16]? Does that even exist?.
Regards
Robin
