Add a comment on why some seq's are done

diff --git a/compiler/stgSyn/CoreToStg.lhs b/compiler/stgSyn/CoreToStg.lhs
index c81edcd..2059937 100644 (file)
--- a/compiler/stgSyn/CoreToStg.lhs
+++ b/compiler/stgSyn/CoreToStg.lhs
@@ -549,6 +549,8 @@ coreToStgApp _ f args = do
                                 -- All the free vars of the args are disqualified
                                 -- from being let-no-escaped.
 
+    -- Forcing these fixes a leak in the code generator, noticed while
+    -- profiling for trac #4367
     app `seq` fvs `seq` seqVarSet vars `seq` return (
         app,
         fvs,