Epic 4: Register allocation (stop "everything on stack")

[aalhour]

Epic 4: Register allocation (stop "everything on stack")

Goal: use liveness + interference graph to allocate registers.

• Decide allocation strategy (graph coloring vs linear scan)
• Implement allocator (use interference graph)
• Spilling strategy + spill cost heuristics
• Caller/callee-saved register handling
• Tests:
  • stress tests designed to force spills
  • correctness tests for calling convention edge cases