> From: Jakub Jelinek [mailto:ja...@redhat.com] > Sent: Monday, June 23, 2014 4:59 PM > > Host could e.g. in theory have CHAR_BIT 32, while target BITS_PER_UNIT 8 > (otherwise bswap pass would give up). sizeof (unsigned HOST_WIDE_INT) > could > very well be 2 in that case.
In this case the pass would skip any value of more than 2 bytes. However although the original comments on struct symbolic_number implies that there is a mapping between host bytes (the bytes of the symbolic number) and target bytes, it isn't the case since do_shift_rotate () shift the symbolic number by quantity of BYTES_PER_UNIT instead of CHAR_BIT. Also there is quite a few 8 here and there. Although not a problem in practice, the mix of 8 and BITS_PER_UNIT does not look very good. I guess a quick review would be in order. Of course, with regards to the backport the mix of 8 and BITS_PER_UNIT should be left as is and only confusion about how to represent a target value into a host type should be fixed if any. I'll come back to you whenever this is done. Best regards, Thomas
