Add instruction flags: hasExtraSrcRegAllocReq and hasExtraDefRegAllocReq. When
set, these flags indicate the instructions source / def operands have special
register allocation requirement that are not captured in their register classes.
Post-allocation passes (e.g. post-alloc scheduler) should not change their
allocations. e.g. ARM::LDRD require the two definitions to be allocated
even / odd register pair.

llvm-svn: 83196
5 files changed
tree: 7edcb8081d80d72d9a839bebf8925252331ffecb
  1. clang/
  2. compiler-rt/
  3. llvm/