[project @ 2003-10-01 10:57:39 by wolfgang]

[ghc-hetmet.git] / ghc / includes / StgMacros.h

diff --git a/ghc/includes/StgMacros.h b/ghc/includes/StgMacros.h
index 473a590..4a5a985 100644 (file)
--- a/ghc/includes/StgMacros.h
+++ b/ghc/includes/StgMacros.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: StgMacros.h,v 1.54 2003/07/28 16:05:36 simonmar Exp $
+ * $Id: StgMacros.h,v 1.56 2003/08/05 14:01:34 simonpj Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -445,6 +445,14 @@ EXTFUN_RTS(stg_gen_block);
 #   else
 // An object is replaced by a blackhole, so we fill the slop with zeros.
 // 
+// This looks like it can't work - we're overwriting the contents of
+// the THUNK with slop!  Perhaps this never worked??? --SDM
+// The problem is that with eager-black-holing we currently perform
+// the black-holing operation at the *beginning* of the basic block,
+// when we still need the contents of the thunk.
+// Perhaps the thing to do is to overwrite it at the *end* of the
+// basic block, when we've already sucked out the thunk's contents? -- SLPJ
+//
 // Todo: maybe use SET_HDR() and remove LDV_recordCreate()?
 // 
 #    define UPD_BH_UPDATABLE(info)             \