1 files changed, 27 insertions, 3 deletions
diff --git a/powerpc/DuplicateOpcodeHeuristic.ml b/powerpc/DuplicateOpcodeHeuristic.ml
index 85505245..33be79e8 100644
--- a/powerpc/DuplicateOpcodeHeuristic.ml
+++ b/powerpc/DuplicateOpcodeHeuristic.ml
@@ -1,3 +1,27 @@
-exception HeuristicSucceeded
-        
-let opcode_heuristic code cond ifso ifnot preferred = ()
+(* open Camlcoq *)
+open Op
+open Integers
+
+let opcode_heuristic code cond ifso ifnot is_loop_header =
+  match cond with
+  | Ccompimm (c, n) | Ccompuimm (c, n) -> if n == Integers.Int.zero then (match c with
+      | Clt | Cle -> Some false
+      | Cgt | Cge -> Some true
+      | _ -> None
+      ) else None
+  | Ccomplimm (c, n) | Ccompluimm (c, n) -> if n == Integers.Int64.zero then (match c with
+      | Clt | Cle -> Some false
+      | Cgt | Cge -> Some true
+      | _ -> None
+      ) else None
+  | Ccompf c -> (match c with
+      | Ceq -> Some false
+      | Cne -> Some true
+      | _ -> None
+      )
+  | Cnotcompf c -> (match c with
+      | Ceq -> Some true
+      | Cne -> Some false
+      | _ -> None
+      )
+  | _ -> None