Jakob Stoklund Olesen b010f9d251 Compute a backwards SubReg -> SubRegIndex map for each register.
This mapping is for internal use by TableGen. It will not be exposed in
the generated files.

Unfortunately, the mapping is not completely well-defined. The X86 xmm
registers appear with multiple sub-register indices in the ymm
registers. This is because of the odd idempotent sub_sd and sub_ss
sub-register indices. I hope to be able to eliminate them entirely, so
we can require the sub-registers to form a tree.

For now, just place the canonical sub_xmm index in the mapping, and
ignore the idempotents.

llvm-svn: 156519
2012-05-09 22:15:00 +00:00
..
2012-04-17 17:21:17 +00:00