Rematerialize as much as possible before inserting spills and reloads.

This allows us to recognize the common case where all uses could be
rematerialized, and no stack slot allocation is necessary.

If some values could be fully rematerialized, remove them from the live range
before allocating a stack slot for the rest.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107492 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed