What padding? bitregion_end-bitregion_start+1 will be 32, but in
Poop, I misread your example.
get_best_mode I see
+ maxbits = bitregion_end - bitpos + 1;
which is 28. No?
Yes, but if you look at the next few lines you'll see:
/* Find the narrowest integer mode that contains the bit field. */
for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
mode = GET_MODE_WIDER_MODE (mode))
{
unit = GET_MODE_BITSIZE (mode);
if ((bitpos % unit) + bitsize <= unit)
break;
}
The narrowest integer mode containing the bit field is still 32, so we
access the bitfield with an SI instruction as expected.
Incidentally, I would expect _end to be one past the end rather than the
index of the last element, but perhaps I just expect that because C++
iterators work that way.
I can fix that.
Aldy
