Big collection of patches for the new codegen branch.

[ghc-hetmet.git] / rts / sm / Scav.c

diff --git a/rts/sm/Scav.c b/rts/sm/Scav.c
index f61d6b7..d396b9f 100644 (file)
--- a/rts/sm/Scav.c
+++ b/rts/sm/Scav.c
@@ -140,7 +140,7 @@ scavenge_arg_block (StgFunInfoTable *fun_info, StgClosure **args)
     return p;
 }
 
-STATIC_INLINE StgPtr
+STATIC_INLINE GNUC_ATTR_HOT StgPtr
 scavenge_PAP_payload (StgClosure *fun, StgClosure **payload, StgWord size)
 {
     StgPtr p;
@@ -179,7 +179,7 @@ scavenge_PAP_payload (StgClosure *fun, StgClosure **payload, StgWord size)
     return p;
 }
 
-STATIC_INLINE StgPtr
+STATIC_INLINE GNUC_ATTR_HOT StgPtr
 scavenge_PAP (StgPAP *pap)
 {
     evacuate(&pap->fun);
@@ -230,7 +230,7 @@ scavenge_large_srt_bitmap( StgLargeSRT *large_srt )
  * srt field in the info table.  That's ok, because we'll
  * never dereference it.
  */
-STATIC_INLINE void
+STATIC_INLINE GNUC_ATTR_HOT void
 scavenge_srt (StgClosure **srt, nat srt_bitmap)
 {
   nat bitmap;
@@ -270,7 +270,7 @@ scavenge_srt (StgClosure **srt, nat srt_bitmap)
 }
 
 
-STATIC_INLINE void
+STATIC_INLINE GNUC_ATTR_HOT void
 scavenge_thunk_srt(const StgInfoTable *info)
 {
     StgThunkInfoTable *thunk_info;
@@ -281,7 +281,7 @@ scavenge_thunk_srt(const StgInfoTable *info)
     scavenge_srt((StgClosure **)GET_SRT(thunk_info), thunk_info->i.srt_bitmap);
 }
 
-STATIC_INLINE void
+STATIC_INLINE GNUC_ATTR_HOT void
 scavenge_fun_srt(const StgInfoTable *info)
 {
     StgFunInfoTable *fun_info;
@@ -304,7 +304,7 @@ scavenge_fun_srt(const StgInfoTable *info)
    idea.  
    -------------------------------------------------------------------------- */
 
-static void
+static GNUC_ATTR_HOT void
 scavenge_block (bdescr *bd)
 {
   StgPtr p, q;
@@ -504,8 +504,6 @@ scavenge_block (bdescr *bd)
        break;
 
     case CAF_BLACKHOLE:
-    case SE_CAF_BLACKHOLE:
-    case SE_BLACKHOLE:
     case BLACKHOLE:
        p += BLACKHOLE_sizeW();
        break;
@@ -745,7 +743,7 @@ linear_scan:
        info = get_itbl((StgClosure *)p);
        
        q = p;
-        switch (((volatile StgWord *)info)[1] & 0xffff) {
+        switch (info->type) {
            
         case MVAR_CLEAN:
         case MVAR_DIRTY:
@@ -881,8 +879,6 @@ linear_scan:
        }
 
        case CAF_BLACKHOLE:
-       case SE_CAF_BLACKHOLE:
-       case SE_BLACKHOLE:
        case BLACKHOLE:
        case ARR_WORDS:
            break;
@@ -1197,8 +1193,6 @@ scavenge_one(StgPtr p)
     }
 
     case CAF_BLACKHOLE:
-    case SE_CAF_BLACKHOLE:
-    case SE_BLACKHOLE:
     case BLACKHOLE:
        break;
        
@@ -1686,24 +1680,34 @@ scavenge_stack(StgPtr p, StgPtr stack_end)
        // the indirection into an IND_PERM, so that evacuate will
        // copy the indirection into the old generation instead of
        // discarding it.
+        //
+        // Note [upd-black-hole]
+        // One slight hiccup is that the THUNK_SELECTOR machinery can
+        // overwrite the updatee with an IND.  In parallel GC, this
+        // could even be happening concurrently, so we can't check for
+        // the IND.  Fortunately if we assume that blackholing is
+        // happening (either lazy or eager), then we can be sure that
+        // the updatee is never a THUNK_SELECTOR and we're ok.
+        // NB. this is a new invariant: blackholing is not optional.
     {
         nat type;
         const StgInfoTable *i;
+        StgClosure *updatee;
 
-        i = ((StgUpdateFrame *)p)->updatee->header.info;
+        updatee = ((StgUpdateFrame *)p)->updatee;
+        i = updatee->header.info;
         if (!IS_FORWARDING_PTR(i)) {
-            type = get_itbl(((StgUpdateFrame *)p)->updatee)->type;
+            type = get_itbl(updatee)->type;
             if (type == IND) {
-                ((StgUpdateFrame *)p)->updatee->header.info = 
-                    (StgInfoTable *)&stg_IND_PERM_info;
+                updatee->header.info = &stg_IND_PERM_info;
             } else if (type == IND_OLDGEN) {
-                ((StgUpdateFrame *)p)->updatee->header.info = 
-                    (StgInfoTable *)&stg_IND_OLDGEN_PERM_info;
+                updatee->header.info = &stg_IND_OLDGEN_PERM_info;
             }            
-            evacuate(&((StgUpdateFrame *)p)->updatee);
-            p += sizeofW(StgUpdateFrame);
-            continue;
         }
+        evacuate(&((StgUpdateFrame *)p)->updatee);
+        ASSERT(GET_CLOSURE_TAG(((StgUpdateFrame *)p)->updatee) == 0);
+        p += sizeofW(StgUpdateFrame);
+        continue;
     }
 
       // small bitmap (< 32 entries, or 64 on a 64-bit machine)