Compiler/VM Optimizations

[SupunS]

Quick wins / Low hanging:

most impactful potentially:

• [Compiler] Optimize conversion between static and sema types #4273
• Reusing the VM (vm.NewVM call, need to make linking result reusable, ensure no values are used concurrently)

other:

• Cache linking results from VM in FVM programs cache. But cannot include interpreter values
• Make NativeFunctionValue, and other large types pointer types
• Lazily allocate bookkeeping structures (e.g. VM context maps) #4239

Long term (more work):

• Peephole optimizations #4305
• Emit VM functions in compiler (Direct Call Threading)
• Re-use getField results where possible (requires liveness analysis)
• Add "resource-ness" (flag) to the static-type. Might need a state migration. (maybe not needed for the initial version)
  • Move resource-ness from instruction to static type (currently instructions have resource-nes operand)
• Optimize conversion function calls
  • Constant literal argument (e.g. UInt32(1)) -> Emit constant load (GetConstant). avoids call
  • Other argument (e.g. let x: UInt8 = 1; UInt32(x)) -> Call specific target/source conversion function ($UInt8ToUInt32(x)). avoids run-time type dispatch in conversion function
• concurrent processing in Cadence