53 lines
1.7 KiB
OCaml
53 lines
1.7 KiB
OCaml
(** Optimizer *)
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open Ll
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module Platform = Util.Platform
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(*
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This file drives the optimization for the compilation. For the leaderboard,
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you may optionally implement additional optimizations by editing this file.
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NOTE: your additional optimizations should run only if !opt_level = 2.
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That is, your additional optimizations should be enabled only when the
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flag -O2 is passed to main.native.
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*)
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(* dead code elimination ---------------------------------------------------- *)
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let dce (g:Cfg.t) : Cfg.t =
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let ag = Alias.analyze g in
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let lg = Liveness.analyze g in
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Dce.run lg ag g
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(* constant propagation ----------------------------------------------------- *)
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let cp (g:Cfg.t) : Cfg.t =
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let cg = Constprop.analyze g in
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Constprop.run cg g
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(* "full" optimization: n rounds of (dce followed by constant) propagation -- *)
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let rec pass n (g:Cfg.t) =
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if n <= 0
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then g
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else pass (n - 1) (g |> dce |> cp)
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(* optimize an fdecl -------------------------------------------------------- *)
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(* runs (two) passes of dce followed by constant propagation on the supplied
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LL IR fdecl. *)
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let opt_fdecl (gid,fdecl:Ll.gid * Ll.fdecl) : Ll.gid * Ll.fdecl =
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let g = pass 2 (Cfg.of_ast fdecl) in
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gid, Cfg.to_ast g
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(* optimization level, set by the main compiler driver *)
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let opt_level = ref 0
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(* optimize each fdecl in the program *)
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let optimize (p:Ll.prog) : Ll.prog =
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if !opt_level = 2 then
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(* OPTIONAL TASK: implement additional optimizations *)
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failwith "No -O2 optimizations implemented! This is an optional task."
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else if !opt_level = 1
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then begin
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Platform.verb @@ Printf.sprintf "..optimizing";
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{ p with Ll.fdecls = List.map opt_fdecl p.Ll.fdecls }
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end
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else p
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