For def/use pruning, the linear address mapping of the x86
sub-registers (e.g., AX represents the lower 16 bits of EAX) must
overlap. If it doesn't, e.g., AX and EAX are considered separate
registers by def/use pruning, resulting in a failure to correlate an
EAX def with a subsequent AX use.
The only user of this mapping up to now, RegisterImporter, forced all
register widths to 8 bits, thereby fortunately canceling out this
problem. Nevertheless it makes no sense to continue encoding a
constant width in these virtual addresses.
Existing trace, fspgroup, fsppilot and result tables may be converted
to the new encoding by using this query:
UPDATE <tablename> SET data_address = ((data_address >> 4) & ~0xf) | data_address & 0xf;
Change-Id: I7a942b78c34f6140803a86af639eeedef3550f34