1 files changed, 77 insertions, 0 deletions
diff --git a/source/xi_lib/analysis.ml b/source/xi_lib/analysis.ml
new file mode 100644
index 0000000..ac15cb5
--- /dev/null
+++ b/source/xi_lib/analysis.ml
@@ -0,0 +1,77 @@
+module Knowledge = struct
+
+  type 'a t =
+    { pre: 'a
+    ; post: 'a
+    }
+
+  let pre t = t.pre
+
+  let post t = t.post
+
+  let alter ?pre ?post t =
+    let t = match pre with
+      | Some pre -> {t with pre = pre}
+      | None -> t
+    in
+    let t = match post with
+      | Some post -> {t with post = post}
+      | None -> t
+    in
+    t
+
+  let make pre post : 'a t = {pre; post}
+
+  type 'a table = (Ir.label, 'a t) Hashtbl.t
+
+end
+
+module BlockKnowledge = struct
+
+  type 'a t =
+    | Simple of 'a Knowledge.t
+    | Complex of
+      { block: 'a Knowledge.t
+      ; body: ('a Knowledge.t * Ir.instr) list
+      ; terminator: 'a Knowledge.t * Ir.terminator
+      }
+
+  let block = function
+    | Simple t -> t
+    | Complex {block; _} -> block
+
+  let pre t = Knowledge.pre @@ block t
+  let post t = Knowledge.post @@ block t
+
+  let terminator = function
+    | Simple _ -> failwith "BlockKnowledge.terminator"
+    | Complex t->  t.terminator
+
+  let body =  function
+    | Simple _ -> failwith "BlockKnowledge.body"
+    | Complex t -> t.body
+
+  let terminator_instr t = snd @@ terminator t
+
+  let terminator_kw t = fst @@ terminator t
+
+  let make_complex ~block ~body ~terminator = 
+    Complex { block; body; terminator }
+
+  let make_simple t = Simple t
+
+  type 'a table = (Ir.label, 'a t) Hashtbl.t
+
+  let alter_prepost ?pre ?post = function
+    | Simple t ->
+      Simple (Knowledge.alter ?pre ?post t)
+
+    | Complex {block; body; terminator} ->
+      let block = Knowledge.alter ?pre ?post block in
+      Complex {block; body; terminator}
+
+  let is_complex = function
+    | Complex _ -> true
+    | Simple _ -> false
+
+end