Do not restore unnecessary instructions before a predicted Icond

If the Icond is the last instruction of the path, the live_renames
includes all the live renames for all successors (s_output_regs).
However not all of those need to be stricly restored before the Icond.
Some can be restored afterwards.

1 files changed, 16 insertions, 10 deletions

diff --git a/scheduling/MyRTLpathScheduleraux.ml b/scheduling/MyRTLpathScheduleraux.ml
index 212867f4..547019a9 100644
--- a/scheduling/MyRTLpathScheduleraux.ml
+++ b/scheduling/MyRTLpathScheduleraux.ml
@@ -392,19 +392,25 @@ let restoration_instructions sb code live_renames =
     | Icond _ -> false
     | _ -> true
   in
+  let open Either in
   let to_insert =
     PTree.fold
       (fun to_insert side_exit_pc renames ->
-        let insts = ListLabels.map renames
-        ~f:(fun {old_name; new_name} ->
-          Iop (Op.Omove, [new_name], old_name, Camlcoq.P.one))
-        in
-        let pos = if last_inst_is_basic
-          then InsertPosition.Below side_exit_pc
-          else InsertPosition.Above side_exit_pc
-        in
-
-        InsertPositionMap.add pos insts to_insert)
+        let live_regs_opt = PTree.get side_exit_pc sb.liveins in
+        let (above, below) =
+          ListLabels.partition_map renames
+          ~f:(fun {old_name; new_name} ->
+            let inst = Iop (Op.Omove, [new_name], old_name, Camlcoq.P.one) in
+            match last_inst_is_basic, live_regs_opt with
+            | true, _ -> Right inst
+            | false, None -> Left inst
+            | false, Some live_regs ->
+              if Regset.mem old_name live_regs then
+                Left inst
+              else Right inst)
+          in
+        InsertPositionMap.add (InsertPosition.Above side_exit_pc) above to_insert
+        |> InsertPositionMap.add (InsertPosition.Below side_exit_pc) below)
       live_renames
       InsertPositionMap.empty
   in