Lightweight ticky-ticky profiling

[ghc-hetmet.git] / compiler / codeGen / CgClosure.lhs

diff --git a/compiler/codeGen/CgClosure.lhs b/compiler/codeGen/CgClosure.lhs
index 99290d2..8337f91 100644 (file)
--- a/compiler/codeGen/CgClosure.lhs
+++ b/compiler/codeGen/CgClosure.lhs
@@ -447,12 +447,12 @@ emitBlackHoleCode is_single_entry
        -- Profiling needs slop filling (to support LDV profiling), so
        -- currently eager blackholing doesn't work with profiling.
        --
-       -- TICKY_TICKY needs EAGER_BLACKHOLING to verify no double-entries of
-       -- single-entry thunks.
-    eager_blackholing 
-       | opt_DoTickyProfiling = True
-       | otherwise            = False
+        -- Previously, eager blackholing was enabled when ticky-ticky
+        -- was on. But it didn't work, and it wasn't strictly necessary 
+        -- to bring back minimal ticky-ticky, so now EAGER_BLACKHOLING 
+        -- is unconditionally disabled. -- krc 1/2007
 
+    eager_blackholing = False 
 \end{code}
 
 \begin{code}
@@ -475,17 +475,9 @@ setupUpdate closure_info code
        ; if closureUpdReqd closure_info
          then do       -- Blackhole the (updatable) CAF:
                { upd_closure <- link_caf closure_info True
-               ; pushUpdateFrame upd_closure code }
+               ; pushUpdateFrame upd_closure code }
          else do
-               {       -- No update reqd, you'd think we don't need to 
-                       -- black-hole it. But when ticky-ticky is on, we 
-                       -- black-hole it regardless, to catch errors in which
-                       -- an allegedly single-entry closure is entered twice
-                       --
-                       -- We discard the pointer returned by link_caf, because
-                       -- we don't push an update frame
-                 whenC opt_DoTickyProfiling -- Blackhole even a SE CAF
-                       (link_caf closure_info False >> nopC)
+               { -- krc: removed some ticky-related code here.
                ; tickyUpdateFrameOmitted
                ; code }
     }