Do not rotate if the CB was already at the end.

1 files changed, 5 insertions, 1 deletions

diff --git a/backend/Duplicateaux.ml b/backend/Duplicateaux.ml
index 425947ce..324acd99 100644
--- a/backend/Duplicateaux.ml
+++ b/backend/Duplicateaux.ml
@@ -1044,9 +1044,13 @@ let extract_upto_icond f code head =
 let rotate_inner_loop f code revmap iloop =
   let header = extract_upto_icond f code iloop.head in
   let limit = !Clflags.option_flooprotate in
-  if count_ignore_nops code header > limit then begin
+  let nb_duplicated = count_ignore_nops code header in
+  if nb_duplicated > limit then begin
     debug "Loop Rotate: too many nodes to duplicate (%d > %d)" (List.length header) limit;
     (code, revmap)
+  end else if nb_duplicated == count_ignore_nops code iloop.body then begin
+    debug "The conditional branch is already at the end! No need to rotate.";
+    (code, revmap)
   end else
     let (code2, revmap2, dupheader, fwmap) = clone code revmap header in
     let code' = ref code2 in