type surgery

1 files changed, 18 insertions, 22 deletions

diff --git a/lo2.ml b/lo2.ml
index 082d580..0f1572b 100644
--- a/lo2.ml
+++ b/lo2.ml
@@ -1,35 +1,28 @@
 type uop = Neg
 type bop = Add | Sub | CLe | CEq
 
-type ('i)     seqi = [ `Nop | `Uop of uop * 'i | `Bop of 'i * bop * 'i ]
-type ('i)     blki = [ `Phi of 'i list | 'i seqi ]
-type ('i, 'b) jmpi = [ `Brz of 'i * 'b * 'b | `Jmp of 'b ]
+type bref = int (* Block references. *)
+type 'op seqi = [ `Nop | `Uop of uop * 'op | `Bop of 'op * bop * 'op ]
+type 'op jmpi = [ `Brz of 'op * bref * bref | `Jmp of bref ]
 
-type ('i, 'b, 'a) bb =
-  { bb_phis: [ `Phi of 'i list ] array
-  ; bb_inss: ('i seqi) array
-  ; bb_jmp: ('i, 'b) jmpi
-  ; mutable bb_anno: 'a
+type ('ins, 'op) bb =
+  { bb_phis: [ `Phi of 'op list ] array
+  ; bb_inss: 'ins array
+  ; bb_jmp: 'op jmpi
   }
 
-type bref = int
-type iref = IRPhi of (bref * int) | IRIns of (bref * int)
-
-type 'a program = ((iref, bref, 'a) bb) array
-
 
-let gb (p: 'a program) (br: bref) = p.(br)
-let gi (p: 'a program) = function
-  | IRPhi (br, pr) -> ((gb p br).bb_phis.(pr) :> iref blki)
-  | IRIns (br, ir) -> ((gb p br).bb_inss.(ir) :> iref blki)
 
 
 (* ** Liveness analysis. ** *)
+type iref = IRPhi of (bref * int) | IRIns of (bref * int)
+type iprog = ((iref seqi, iref) bb) array
+
 module IRSet = Set.Make(
   struct type t = iref let compare = compare end
 )
 
-let liveness (p: 'a program) =
+let liveness (p: iprog) =
   let module H = Hashtbl in
   let changed = ref true in (* Witness for fixpoint. *)
   let lh = H.create 1001 in
@@ -43,7 +36,7 @@ let liveness (p: 'a program) =
       H.replace lh ir' (IRSet.add ir lir');
     end in
   let succs (b, i) = (* Successor nodes of an instruction. *)
-    let bb = gb p b in
+    let bb = p.(b) in
     if i+1 = Array.length bb.bb_inss then
       if b+1 = Array.length p then [] else
       match bb.bb_jmp with
@@ -51,7 +44,7 @@ let liveness (p: 'a program) =
       | `Jmp b1 -> [(b1, 0)]
     else [(b, i+1)] in
   let gen (b, i) = IRSet.of_list
-    begin match (gb p b).bb_inss.(i) with
+    begin match p.(b).bb_inss.(i) with
     | `Uop (_, i1) -> [i1]
     | `Bop (i1, _, i2) -> [i1; i2]
     | `Nop -> []
@@ -63,7 +56,7 @@ let liveness (p: 'a program) =
   while !changed do
     changed := false;
     for b = Array.length p - 1 downto 0 do
-      let bb = gb p b in
+      let bb = p.(b) in
       for i = Array.length bb.bb_inss - 1 downto 0 do
         let ir = (b, i) in
         let live = List.fold_left (fun live ir' ->
@@ -76,10 +69,13 @@ let liveness (p: 'a program) =
           | IRPhi (b, _) | IRIns (b, _) -> b in
         List.iter (fun ir ->
           let br = blk ir in
-          let bb = gb p br in
+          let bb = p.(br) in
           setlive ir (br, Array.length bb.bb_inss - 1)
         ) il
       ) bb.bb_phis;
     done
   done;
   lh (* Return the final hash table. *)
+
+(* ** Register allocation. ** *)
+type loc = LVoid | LReg of int | LSpill of int