llvm-svn: 34985

Register scavenger is now capable of scavenging. It spills a register whose use of furthest away to make it available.

llvm-svn: 34964

llvm-svn: 34844

llvm-svn: 34784

llvm-svn: 34770

llvm-svn: 34700

llvm-svn: 34698

llvm-svn: 34690

forward() should not increment internal iterator. Its client may insert instruction between now and next forward() call.

llvm-svn: 34649

llvm-svn: 34596

llvm-svn: 34525

Initial check in of register scavenger. Its only current functionality is tracking live registers per MBB.

llvm-svn: 34511