TODOs.markdown

Missing Optimisations

Heap check hoisting

Unnecessary evals

Consider the function:

 infList :: Int -> List Int
 infList n =
   let l1 = Cons n l2; l2 = Cons n l1 in l1

The generated code currently looks like this:

    alloc_frame 3
0   r1 = <blackhole>
1   r2 = &Cons_con_info
2   r1 = alloc(r2, r0, r1)
3   r0 = alloc(r2, r0, r1)
4   Mem[r1 + 2] = r0
5   eval r0 {r0}
6   return r0

Note the eval at instruction 5. We know that r0 has constructor Cons because we just allocated it, so the call to eval will return immediately and can be removed.

Trace Selection

• How much polymorphism is introduced by EVAL?

• Should we specialise per call-site rather than per function?

• Use traces at all, or use some hybrid scheme?

Benchmarks

• Are micro-benchmarks enough?

• A compiler (or type checker) could be interesting -- lots of nested case expressions. This is a good test whether trace sizes can become large.