Manage Inits in a FoldingSet. This provides several benefits:
- Memory for Inits is properly managed
- Duplicate Inits are folded into Flyweights, saving memory
- It enforces const-correctness, protecting against certain classes
of bugs
The above benefits allow Inits to be used in more contexts, which in
turn provides more dynamism to TableGen. This enhanced capability
will be used by the AVX code generator to a fold common patterns
together.
llvm-svn: 134907
This allows the (many) pseudo-instructions we have that map onto a single
real instruction to have their expansion during MC lowering handled
automatically instead of the current cumbersome manual expansion required.
These sorts of pseudos are common when an instruction is used in situations
that require different MachineInstr flags (isTerminator, isBranch, et. al.)
than the generic instruction description has. For example, using a move
to the PC to implement a branch.
llvm-svn: 134704
Peter Collingbourne