make the smp way RTS-only, normal libraries now work with -smp

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

diff --git a/ghc/compiler/codeGen/ClosureInfo.lhs b/ghc/compiler/codeGen/ClosureInfo.lhs
index a5362e6..84d9dd9 100644 (file)
--- a/ghc/compiler/codeGen/ClosureInfo.lhs
+++ b/ghc/compiler/codeGen/ClosureInfo.lhs
@@ -61,11 +61,10 @@ import SMRep                -- all of it
 
 import CLabel
 
-import Constants       ( mIN_UPD_SIZE, mIN_SIZE_NonUpdHeapObject )
+import Constants       ( mIN_PAYLOAD_SIZE )
 import Packages                ( isDllName, HomeModules )
 import StaticFlags     ( opt_SccProfilingOn, opt_OmitBlackHoling,
-                         opt_Parallel, opt_DoTickyProfiling,
-                         opt_SMP )
+                         opt_Parallel, opt_DoTickyProfiling )
 import Id              ( Id, idType, idArity, idName )
 import DataCon         ( DataCon, dataConTyCon, isNullaryRepDataCon, dataConName )
 import Name            ( Name, nameUnique, getOccName, getOccString )
@@ -387,16 +386,8 @@ Computing slop size.  WARNING: this looks dodgy --- it has deep
 knowledge of what the storage manager does with the various
 representations...
 
-Slop Requirements:
-
- - Updatable closures must be mIN_UPD_SIZE.
-
- - Heap-resident Closures must be mIN_SIZE_NonUpdHeapObject
-   (to make room for an StgEvacuated during GC).
-
-In SMP mode, we don't play the mIN_UPD_SIZE game.  Instead, every
-thunk gets an extra padding word in the header, which takes the
-the updated value.
+Slop Requirements: every thunk gets an extra padding word in the
+header, which takes the the updated value.
 
 \begin{code}
 slopSize cl_info = computeSlopSize payload_size cl_info
@@ -423,16 +414,14 @@ minPayloadSize smrep updatable
        BlackHoleRep                            -> min_upd_size
        GenericRep _ _ _ _      | updatable     -> min_upd_size
        GenericRep True _ _ _                   -> 0 -- static
-       GenericRep False _ _ _                  -> mIN_SIZE_NonUpdHeapObject
+       GenericRep False _ _ _                  -> mIN_PAYLOAD_SIZE
           --       ^^^^^___ dynamic
   where
-   min_upd_size
-       | opt_SMP   = ASSERT(mIN_SIZE_NonUpdHeapObject <= 
-                               sIZEOF_StgSMPThunkHeader)
-                     0         -- check that we already have enough
-                               -- room for mIN_SIZE_NonUpdHeapObject,
-                               -- due to the extra header word in SMP
-       | otherwise = mIN_UPD_SIZE
+   min_upd_size =
+       ASSERT(mIN_PAYLOAD_SIZE <= sIZEOF_StgSMPThunkHeader)
+       0       -- check that we already have enough
+               -- room for mIN_SIZE_NonUpdHeapObject,
+               -- due to the extra header word in SMP
 \end{code}
 
 %************************************************************************
@@ -600,9 +589,11 @@ getCallMethod hmods name (LFThunk _ _ updatable std_form_info is_fun) n_args
                -- is the fast-entry code]
 
   | updatable || opt_DoTickyProfiling  -- to catch double entry
-             || opt_SMP    -- Always enter via node on SMP, since the
-                           -- thunk might have been blackholed in the 
-                           -- meantime.
+      {- OLD: || opt_SMP
+        I decided to remove this, because in SMP mode it doesn't matter
+        if we enter the same thunk multiple times, so the optimisation
+        of jumping directly to the entry code is still valid.  --SDM
+       -}
   = ASSERT( n_args == 0 ) EnterIt
 
   | otherwise  -- Jump direct to code for single-entry thunks