-- For Reg -> Reg moves, if the first reg dies at the same time the second reg is born
-- then the mov only serves to join live ranges. The two regs can be renamed to be
-- the same and the move instruction safely erased.
-
regCoalesce
:: Instruction instr
=> [LiveCmmTop instr]
-- | Slurp out mov instructions that only serve to join live ranges.
-- During a mov, if the source reg dies and the destiation reg is born
-- then we can rename the two regs to the same thing and eliminate the move.
---
slurpJoinMovs
:: Instruction instr
=> LiveCmmTop instr