Rename some mutable closure types for consistency

SMALL_MUT_ARR_PTRS_FROZEN0 -> SMALL_MUT_ARR_PTRS_FROZEN_DIRTY
SMALL_MUT_ARR_PTRS_FROZEN  -> SMALL_MUT_ARR_PTRS_FROZEN_CLEAN
MUT_ARR_PTRS_FROZEN0       -> MUT_ARR_PTRS_FROZEN_DIRTY
MUT_ARR_PTRS_FROZEN        -> MUT_ARR_PTRS_FROZEN_CLEAN

Naming is now consistent with other CLEAR/DIRTY objects (MVAR, MUT_VAR,
MUT_ARR_PTRS).

(alternatively we could rename MVAR_DIRTY/MVAR_CLEAN etc. to MVAR0/MVAR)

Removed a few comments in Scav.c about FROZEN0 being on the mut_list
because it's now clear from the closure type.

Reviewers: bgamari, simonmar, erikd

Reviewed By: simonmar

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4784

24 files changed, 152 insertions, 176 deletions

diff --git a/compiler/cmm/CLabel.hs b/compiler/cmm/CLabel.hs
index 3553283890..1a9bc73add 100644
--- a/compiler/cmm/CLabel.hs
+++ b/compiler/cmm/CLabel.hs
@@ -45,11 +45,11 @@ module CLabel (
         mkBHUpdInfoLabel,
         mkIndStaticInfoLabel,
         mkMainCapabilityLabel,
-        mkMAP_FROZEN_infoLabel,
-        mkMAP_FROZEN0_infoLabel,
+        mkMAP_FROZEN_CLEAN_infoLabel,
+        mkMAP_FROZEN_DIRTY_infoLabel,
         mkMAP_DIRTY_infoLabel,
-        mkSMAP_FROZEN_infoLabel,
-        mkSMAP_FROZEN0_infoLabel,
+        mkSMAP_FROZEN_CLEAN_infoLabel,
+        mkSMAP_FROZEN_DIRTY_infoLabel,
         mkSMAP_DIRTY_infoLabel,
         mkBadAlignmentLabel,
         mkArrWords_infoLabel,
@@ -486,11 +486,12 @@ mkBlockInfoTableLabel name c = IdLabel name c BlockInfoTable
 -- Constructing Cmm Labels
 mkDirty_MUT_VAR_Label, mkSplitMarkerLabel, mkUpdInfoLabel,
     mkBHUpdInfoLabel, mkIndStaticInfoLabel, mkMainCapabilityLabel,
-    mkMAP_FROZEN_infoLabel, mkMAP_FROZEN0_infoLabel, mkMAP_DIRTY_infoLabel,
+    mkMAP_FROZEN_CLEAN_infoLabel, mkMAP_FROZEN_DIRTY_infoLabel,
+    mkMAP_DIRTY_infoLabel,
     mkArrWords_infoLabel,
     mkTopTickyCtrLabel,
     mkCAFBlackHoleInfoTableLabel,
-    mkSMAP_FROZEN_infoLabel, mkSMAP_FROZEN0_infoLabel,
+    mkSMAP_FROZEN_CLEAN_infoLabel, mkSMAP_FROZEN_DIRTY_infoLabel,
     mkSMAP_DIRTY_infoLabel, mkBadAlignmentLabel :: CLabel
 mkDirty_MUT_VAR_Label           = mkForeignLabel (fsLit "dirty_MUT_VAR") Nothing ForeignLabelInExternalPackage IsFunction
 mkSplitMarkerLabel              = CmmLabel rtsUnitId (fsLit "__stg_split_marker")    CmmCode
@@ -498,14 +499,14 @@ mkUpdInfoLabel                  = CmmLabel rtsUnitId (fsLit "stg_upd_frame")
 mkBHUpdInfoLabel                = CmmLabel rtsUnitId (fsLit "stg_bh_upd_frame" )     CmmInfo
 mkIndStaticInfoLabel            = CmmLabel rtsUnitId (fsLit "stg_IND_STATIC")        CmmInfo
 mkMainCapabilityLabel           = CmmLabel rtsUnitId (fsLit "MainCapability")        CmmData
-mkMAP_FROZEN_infoLabel          = CmmLabel rtsUnitId (fsLit "stg_MUT_ARR_PTRS_FROZEN") CmmInfo
-mkMAP_FROZEN0_infoLabel         = CmmLabel rtsUnitId (fsLit "stg_MUT_ARR_PTRS_FROZEN0") CmmInfo
+mkMAP_FROZEN_CLEAN_infoLabel    = CmmLabel rtsUnitId (fsLit "stg_MUT_ARR_PTRS_FROZEN_CLEAN") CmmInfo
+mkMAP_FROZEN_DIRTY_infoLabel    = CmmLabel rtsUnitId (fsLit "stg_MUT_ARR_PTRS_FROZEN_DIRTY") CmmInfo
 mkMAP_DIRTY_infoLabel           = CmmLabel rtsUnitId (fsLit "stg_MUT_ARR_PTRS_DIRTY") CmmInfo
 mkTopTickyCtrLabel              = CmmLabel rtsUnitId (fsLit "top_ct")                CmmData
 mkCAFBlackHoleInfoTableLabel    = CmmLabel rtsUnitId (fsLit "stg_CAF_BLACKHOLE")     CmmInfo
 mkArrWords_infoLabel            = CmmLabel rtsUnitId (fsLit "stg_ARR_WORDS")         CmmInfo
-mkSMAP_FROZEN_infoLabel         = CmmLabel rtsUnitId (fsLit "stg_SMALL_MUT_ARR_PTRS_FROZEN") CmmInfo
-mkSMAP_FROZEN0_infoLabel        = CmmLabel rtsUnitId (fsLit "stg_SMALL_MUT_ARR_PTRS_FROZEN0") CmmInfo
+mkSMAP_FROZEN_CLEAN_infoLabel   = CmmLabel rtsUnitId (fsLit "stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN") CmmInfo
+mkSMAP_FROZEN_DIRTY_infoLabel   = CmmLabel rtsUnitId (fsLit "stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY") CmmInfo
 mkSMAP_DIRTY_infoLabel          = CmmLabel rtsUnitId (fsLit "stg_SMALL_MUT_ARR_PTRS_DIRTY") CmmInfo
 mkBadAlignmentLabel             = CmmLabel rtsUnitId (fsLit "stg_badAlignment")      CmmEntry
 
diff --git a/compiler/codeGen/StgCmmPrim.hs b/compiler/codeGen/StgCmmPrim.hs
index fe89955285..da18949846 100644
--- a/compiler/codeGen/StgCmmPrim.hs
+++ b/compiler/codeGen/StgCmmPrim.hs
@@ -194,7 +194,7 @@ shouldInlinePrimOp _ CopyMutableArrayArrayOp
 
 shouldInlinePrimOp dflags CloneArrayOp [src, src_off, (CmmLit (CmmInt n w))]
   | wordsToBytes dflags (asUnsigned w n) <= fromIntegral (maxInlineAllocSize dflags) =
-      Just $ \ [res] -> emitCloneArray mkMAP_FROZEN_infoLabel res src src_off (fromInteger n)
+      Just $ \ [res] -> emitCloneArray mkMAP_FROZEN_CLEAN_infoLabel res src src_off (fromInteger n)
 
 shouldInlinePrimOp dflags CloneMutableArrayOp [src, src_off, (CmmLit (CmmInt n w))]
   | wordsToBytes dflags (asUnsigned w n) <= fromIntegral (maxInlineAllocSize dflags) =
@@ -202,7 +202,7 @@ shouldInlinePrimOp dflags CloneMutableArrayOp [src, src_off, (CmmLit (CmmInt n w
 
 shouldInlinePrimOp dflags FreezeArrayOp [src, src_off, (CmmLit (CmmInt n w))]
   | wordsToBytes dflags (asUnsigned w n) <= fromIntegral (maxInlineAllocSize dflags) =
-      Just $ \ [res] -> emitCloneArray mkMAP_FROZEN_infoLabel res src src_off (fromInteger n)
+      Just $ \ [res] -> emitCloneArray mkMAP_FROZEN_CLEAN_infoLabel res src src_off (fromInteger n)
 
 shouldInlinePrimOp dflags ThawArrayOp [src, src_off, (CmmLit (CmmInt n w))]
   | wordsToBytes dflags (asUnsigned w n) <= fromIntegral (maxInlineAllocSize dflags) =
@@ -227,7 +227,7 @@ shouldInlinePrimOp _ CopySmallMutableArrayOp
 
 shouldInlinePrimOp dflags CloneSmallArrayOp [src, src_off, (CmmLit (CmmInt n w))]
   | wordsToBytes dflags (asUnsigned w n) <= fromIntegral (maxInlineAllocSize dflags) =
-      Just $ \ [res] -> emitCloneSmallArray mkSMAP_FROZEN_infoLabel res src src_off (fromInteger n)
+      Just $ \ [res] -> emitCloneSmallArray mkSMAP_FROZEN_CLEAN_infoLabel res src src_off (fromInteger n)
 
 shouldInlinePrimOp dflags CloneSmallMutableArrayOp [src, src_off, (CmmLit (CmmInt n w))]
   | wordsToBytes dflags (asUnsigned w n) <= fromIntegral (maxInlineAllocSize dflags) =
@@ -235,7 +235,7 @@ shouldInlinePrimOp dflags CloneSmallMutableArrayOp [src, src_off, (CmmLit (CmmIn
 
 shouldInlinePrimOp dflags FreezeSmallArrayOp [src, src_off, (CmmLit (CmmInt n w))]
   | wordsToBytes dflags (asUnsigned w n) <= fromIntegral (maxInlineAllocSize dflags) =
-      Just $ \ [res] -> emitCloneSmallArray mkSMAP_FROZEN_infoLabel res src src_off (fromInteger n)
+      Just $ \ [res] -> emitCloneSmallArray mkSMAP_FROZEN_CLEAN_infoLabel res src src_off (fromInteger n)
 
 shouldInlinePrimOp dflags ThawSmallArrayOp [src, src_off, (CmmLit (CmmInt n w))]
   | wordsToBytes dflags (asUnsigned w n) <= fromIntegral (maxInlineAllocSize dflags) =
@@ -383,20 +383,20 @@ emitPrimOp dflags [res] DataToTagOp [arg]
 
 --  #define unsafeFreezzeArrayzh(r,a)
 --      {
---        SET_INFO((StgClosure *)a,&stg_MUT_ARR_PTRS_FROZEN0_info);
+--        SET_INFO((StgClosure *)a,&stg_MUT_ARR_PTRS_FROZEN_DIRTY_info);
 --        r = a;
 --      }
 emitPrimOp _      [res] UnsafeFreezeArrayOp [arg]
    = emit $ catAGraphs
-   [ setInfo arg (CmmLit (CmmLabel mkMAP_FROZEN0_infoLabel)),
+   [ setInfo arg (CmmLit (CmmLabel mkMAP_FROZEN_DIRTY_infoLabel)),
      mkAssign (CmmLocal res) arg ]
 emitPrimOp _      [res] UnsafeFreezeArrayArrayOp [arg]
    = emit $ catAGraphs
-   [ setInfo arg (CmmLit (CmmLabel mkMAP_FROZEN0_infoLabel)),
+   [ setInfo arg (CmmLit (CmmLabel mkMAP_FROZEN_DIRTY_infoLabel)),
      mkAssign (CmmLocal res) arg ]
 emitPrimOp _      [res] UnsafeFreezeSmallArrayOp [arg]
    = emit $ catAGraphs
-   [ setInfo arg (CmmLit (CmmLabel mkSMAP_FROZEN0_infoLabel)),
+   [ setInfo arg (CmmLit (CmmLabel mkSMAP_FROZEN_DIRTY_infoLabel)),
      mkAssign (CmmLocal res) arg ]
 
 --  #define unsafeFreezzeByteArrayzh(r,a)       r=(a)
diff --git a/includes/rts/storage/ClosureMacros.h b/includes/rts/storage/ClosureMacros.h
index dcbc95b31b..71d53ae8a2 100644
--- a/includes/rts/storage/ClosureMacros.h
+++ b/includes/rts/storage/ClosureMacros.h
@@ -401,13 +401,13 @@ closure_sizeW_ (const StgClosure *p, const StgInfoTable *info)
         return arr_words_sizeW((StgArrBytes *)p);
     case MUT_ARR_PTRS_CLEAN:
     case MUT_ARR_PTRS_DIRTY:
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
         return mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
     case SMALL_MUT_ARR_PTRS_CLEAN:
     case SMALL_MUT_ARR_PTRS_DIRTY:
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-    case SMALL_MUT_ARR_PTRS_FROZEN0:
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+    case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
         return small_mut_arr_ptrs_sizeW((StgSmallMutArrPtrs*)p);
     case TSO:
         return sizeofW(StgTSO);
diff --git a/includes/rts/storage/ClosureTypes.h b/includes/rts/storage/ClosureTypes.h
index 443efed5f1..85dc1a0ce4 100644
--- a/includes/rts/storage/ClosureTypes.h
+++ b/includes/rts/storage/ClosureTypes.h
@@ -64,8 +64,8 @@
 #define ARR_WORDS                     42
 #define MUT_ARR_PTRS_CLEAN            43
 #define MUT_ARR_PTRS_DIRTY            44
-#define MUT_ARR_PTRS_FROZEN0          45
-#define MUT_ARR_PTRS_FROZEN           46
+#define MUT_ARR_PTRS_FROZEN_DIRTY     45
+#define MUT_ARR_PTRS_FROZEN_CLEAN     46
 #define MUT_VAR_CLEAN                 47
 #define MUT_VAR_DIRTY                 48
 #define WEAK                          49
@@ -80,7 +80,7 @@
 #define WHITEHOLE                     58
 #define SMALL_MUT_ARR_PTRS_CLEAN      59
 #define SMALL_MUT_ARR_PTRS_DIRTY      60
-#define SMALL_MUT_ARR_PTRS_FROZEN0    61
-#define SMALL_MUT_ARR_PTRS_FROZEN     62
+#define SMALL_MUT_ARR_PTRS_FROZEN_DIRTY 61
+#define SMALL_MUT_ARR_PTRS_FROZEN_CLEAN 62
 #define COMPACT_NFDATA                63
 #define N_CLOSURE_TYPES               64
diff --git a/includes/stg/MiscClosures.h b/includes/stg/MiscClosures.h
index a976b6b5fd..98363b342b 100644
--- a/includes/stg/MiscClosures.h
+++ b/includes/stg/MiscClosures.h
@@ -116,12 +116,12 @@ RTS_ENTRY(stg_ARR_WORDS);
 RTS_ENTRY(stg_MUT_ARR_WORDS);
 RTS_ENTRY(stg_MUT_ARR_PTRS_CLEAN);
 RTS_ENTRY(stg_MUT_ARR_PTRS_DIRTY);
-RTS_ENTRY(stg_MUT_ARR_PTRS_FROZEN);
-RTS_ENTRY(stg_MUT_ARR_PTRS_FROZEN0);
+RTS_ENTRY(stg_MUT_ARR_PTRS_FROZEN_CLEAN);
+RTS_ENTRY(stg_MUT_ARR_PTRS_FROZEN_DIRTY);
 RTS_ENTRY(stg_SMALL_MUT_ARR_PTRS_CLEAN);
 RTS_ENTRY(stg_SMALL_MUT_ARR_PTRS_DIRTY);
-RTS_ENTRY(stg_SMALL_MUT_ARR_PTRS_FROZEN);
-RTS_ENTRY(stg_SMALL_MUT_ARR_PTRS_FROZEN0);
+RTS_ENTRY(stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN);
+RTS_ENTRY(stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY);
 RTS_ENTRY(stg_MUT_VAR_CLEAN);
 RTS_ENTRY(stg_MUT_VAR_DIRTY);
 RTS_ENTRY(stg_END_TSO_QUEUE);
diff --git a/libraries/ghc-heap/GHC/Exts/Heap.hs b/libraries/ghc-heap/GHC/Exts/Heap.hs
index 61fab5f1c9..9dc1f94a67 100644
--- a/libraries/ghc-heap/GHC/Exts/Heap.hs
+++ b/libraries/ghc-heap/GHC/Exts/Heap.hs
@@ -224,7 +224,7 @@ getClosure x = do
                         ++ show (length rawWds)
             pure $ ArrWordsClosure itbl (head rawWds) (tail rawWds)
 
-        t | t >= MUT_ARR_PTRS_CLEAN && t <= MUT_ARR_PTRS_FROZEN -> do
+        t | t >= MUT_ARR_PTRS_CLEAN && t <= MUT_ARR_PTRS_FROZEN_CLEAN -> do
             unless (length rawWds >= 2) $
                 fail $ "Expected at least 2 words to MUT_ARR_PTRS_* "
                         ++ "found " ++ show (length rawWds)
diff --git a/libraries/ghc-heap/GHC/Exts/Heap/ClosureTypes.hs b/libraries/ghc-heap/GHC/Exts/Heap/ClosureTypes.hs
index 507561fbee..7cd85fe99e 100644
--- a/libraries/ghc-heap/GHC/Exts/Heap/ClosureTypes.hs
+++ b/libraries/ghc-heap/GHC/Exts/Heap/ClosureTypes.hs
@@ -57,8 +57,8 @@ data ClosureType
     | ARR_WORDS
     | MUT_ARR_PTRS_CLEAN
     | MUT_ARR_PTRS_DIRTY
-    | MUT_ARR_PTRS_FROZEN0
-    | MUT_ARR_PTRS_FROZEN
+    | MUT_ARR_PTRS_FROZEN_DIRTY
+    | MUT_ARR_PTRS_FROZEN_CLEAN
     | MUT_VAR_CLEAN
     | MUT_VAR_DIRTY
     | WEAK
@@ -73,8 +73,8 @@ data ClosureType
     | WHITEHOLE
     | SMALL_MUT_ARR_PTRS_CLEAN
     | SMALL_MUT_ARR_PTRS_DIRTY
-    | SMALL_MUT_ARR_PTRS_FROZEN0
-    | SMALL_MUT_ARR_PTRS_FROZEN
+    | SMALL_MUT_ARR_PTRS_FROZEN_DIRTY
+    | SMALL_MUT_ARR_PTRS_FROZEN_CLEAN
     | COMPACT_NFDATA
     | N_CLOSURE_TYPES
  deriving (Enum, Eq, Ord, Show)
diff --git a/rts/CheckUnload.c b/rts/CheckUnload.c
index c3958e938e..fa4843d8e4 100644
--- a/rts/CheckUnload.c
+++ b/rts/CheckUnload.c
@@ -200,16 +200,16 @@ static void searchHeapBlocks (HashTable *addrs, bdescr *bd)
 
             case MUT_ARR_PTRS_CLEAN:
             case MUT_ARR_PTRS_DIRTY:
-            case MUT_ARR_PTRS_FROZEN:
-            case MUT_ARR_PTRS_FROZEN0:
+            case MUT_ARR_PTRS_FROZEN_CLEAN:
+            case MUT_ARR_PTRS_FROZEN_DIRTY:
                 prim = true;
                 size = mut_arr_ptrs_sizeW((StgMutArrPtrs *)p);
                 break;
 
             case SMALL_MUT_ARR_PTRS_CLEAN:
             case SMALL_MUT_ARR_PTRS_DIRTY:
-            case SMALL_MUT_ARR_PTRS_FROZEN:
-            case SMALL_MUT_ARR_PTRS_FROZEN0:
+            case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+            case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
                 prim = true;
                 size = small_mut_arr_ptrs_sizeW((StgSmallMutArrPtrs *)p);
                 break;
diff --git a/rts/ClosureFlags.c b/rts/ClosureFlags.c
index 9bf301552d..f8dba8f326 100644
--- a/rts/ClosureFlags.c
+++ b/rts/ClosureFlags.c
@@ -66,8 +66,8 @@ StgWord16 closure_flags[] = {
  [ARR_WORDS]            =  (_HNF|     _NS|         _UPT           ),
  [MUT_ARR_PTRS_CLEAN]   =  (_HNF|     _NS|    _MUT|_UPT           ),
  [MUT_ARR_PTRS_DIRTY]   =  (_HNF|     _NS|    _MUT|_UPT           ),
- [MUT_ARR_PTRS_FROZEN0] =  (_HNF|     _NS|    _MUT|_UPT           ),
- [MUT_ARR_PTRS_FROZEN]  =  (_HNF|     _NS|         _UPT           ),
+ [MUT_ARR_PTRS_FROZEN_DIRTY] =  (_HNF|     _NS|    _MUT|_UPT           ),
+ [MUT_ARR_PTRS_FROZEN_CLEAN] =  (_HNF|     _NS|         _UPT           ),
  [MUT_VAR_CLEAN]        =  (_HNF|     _NS|    _MUT|_UPT           ),
  [MUT_VAR_DIRTY]        =  (_HNF|     _NS|    _MUT|_UPT           ),
  [WEAK]                 =  (_HNF|     _NS|         _UPT           ),
@@ -80,10 +80,10 @@ StgWord16 closure_flags[] = {
  [CATCH_RETRY_FRAME]    =  (     _BTM                             ),
  [CATCH_STM_FRAME]      =  (     _BTM                             ),
  [WHITEHOLE]            =  ( 0                                    ),
- [SMALL_MUT_ARR_PTRS_CLEAN]   =  (_HNF|     _NS|     _MUT|_UPT           ),
- [SMALL_MUT_ARR_PTRS_DIRTY]   =  (_HNF|     _NS|     _MUT|_UPT           ),
- [SMALL_MUT_ARR_PTRS_FROZEN0] =  (_HNF|     _NS|     _MUT|_UPT           ),
- [SMALL_MUT_ARR_PTRS_FROZEN]  =  (_HNF|     _NS|          _UPT           ),
+ [SMALL_MUT_ARR_PTRS_CLEAN] =  (_HNF|     _NS|     _MUT|_UPT           ),
+ [SMALL_MUT_ARR_PTRS_DIRTY] =  (_HNF|     _NS|     _MUT|_UPT           ),
+ [SMALL_MUT_ARR_PTRS_FROZEN_DIRTY] =  (_HNF|     _NS|     _MUT|_UPT           ),
+ [SMALL_MUT_ARR_PTRS_FROZEN_CLEAN] =  (_HNF|     _NS|          _UPT           ),
  [COMPACT_NFDATA]       =  (_HNF|     _NS                              ),
 };
 
diff --git a/rts/Compact.cmm b/rts/Compact.cmm
index 2c8a030ed1..061646846d 100644
--- a/rts/Compact.cmm
+++ b/rts/Compact.cmm
@@ -154,8 +154,8 @@ eval:
     }
 
     case
-        MUT_ARR_PTRS_FROZEN0,
-        MUT_ARR_PTRS_FROZEN: {
+        MUT_ARR_PTRS_FROZEN_DIRTY,
+        MUT_ARR_PTRS_FROZEN_CLEAN: {
 
         (should) = ccall shouldCompact(compact "ptr", p "ptr");
         if (should == SHOULDCOMPACT_IN_CNF) { P_[pp] = p; return(); }
@@ -186,8 +186,8 @@ eval:
     }
 
     case
-        SMALL_MUT_ARR_PTRS_FROZEN0,
-        SMALL_MUT_ARR_PTRS_FROZEN: {
+        SMALL_MUT_ARR_PTRS_FROZEN_DIRTY,
+        SMALL_MUT_ARR_PTRS_FROZEN_CLEAN: {
 
         (should) = ccall shouldCompact(compact "ptr", p "ptr");
         if (should == SHOULDCOMPACT_IN_CNF) { P_[pp] = p; return(); }
diff --git a/rts/Heap.c b/rts/Heap.c
index 14289b896f..7ab628d2da 100644
--- a/rts/Heap.c
+++ b/rts/Heap.c
@@ -181,8 +181,8 @@ StgMutArrPtrs *heap_view_closurePtrs(Capability *cap, StgClosure *closure) {
 
         case MUT_ARR_PTRS_CLEAN:
         case MUT_ARR_PTRS_DIRTY:
-        case MUT_ARR_PTRS_FROZEN:
-        case MUT_ARR_PTRS_FROZEN0:
+        case MUT_ARR_PTRS_FROZEN_CLEAN:
+        case MUT_ARR_PTRS_FROZEN_DIRTY:
             for (i = 0; i < ((StgMutArrPtrs *)closure)->ptrs; ++i) {
                 ptrs[nptrs++] = ((StgMutArrPtrs *)closure)->payload[i];
             }
@@ -208,7 +208,7 @@ StgMutArrPtrs *heap_view_closurePtrs(Capability *cap, StgClosure *closure) {
     StgMutArrPtrs *arr =
         (StgMutArrPtrs *)allocate(cap, sizeofW(StgMutArrPtrs) + size);
     TICK_ALLOC_PRIM(sizeofW(StgMutArrPtrs), nptrs, 0);
-    SET_HDR(arr, &stg_MUT_ARR_PTRS_FROZEN_info, cap->r.rCCCS);
+    SET_HDR(arr, &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info, cap->r.rCCCS);
     arr->ptrs = nptrs;
     arr->size = size;
 
diff --git a/rts/LdvProfile.c b/rts/LdvProfile.c
index 789941603a..9499fdb7cb 100644
--- a/rts/LdvProfile.c
+++ b/rts/LdvProfile.c
@@ -66,12 +66,12 @@ processHeapClosureForDead( const StgClosure *c )
     case TVAR:
     case MUT_ARR_PTRS_CLEAN:
     case MUT_ARR_PTRS_DIRTY:
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
     case SMALL_MUT_ARR_PTRS_CLEAN:
     case SMALL_MUT_ARR_PTRS_DIRTY:
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-    case SMALL_MUT_ARR_PTRS_FROZEN0:
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+    case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
     case ARR_WORDS:
     case WEAK:
     case MUT_VAR_CLEAN:
diff --git a/rts/PrimOps.cmm b/rts/PrimOps.cmm
index 293c4fea0c..6986d9b527 100644
--- a/rts/PrimOps.cmm
+++ b/rts/PrimOps.cmm
@@ -275,28 +275,15 @@ stg_newArrayzh ( W_ n /* words */, gcptr init )
 
 stg_unsafeThawArrayzh ( gcptr arr )
 {
-    // SUBTLETY TO DO WITH THE OLD GEN MUTABLE LIST
-    //
-    // A MUT_ARR_PTRS lives on the mutable list, but a MUT_ARR_PTRS_FROZEN
-    // normally doesn't.  However, when we freeze a MUT_ARR_PTRS, we leave
-    // it on the mutable list for the GC to remove (removing something from
-    // the mutable list is not easy).
-    //
-    // So that we can tell whether a MUT_ARR_PTRS_FROZEN is on the mutable list,
-    // when we freeze it we set the info ptr to be MUT_ARR_PTRS_FROZEN0
-    // to indicate that it is still on the mutable list.
-    //
-    // So, when we thaw a MUT_ARR_PTRS_FROZEN, we must cope with two cases:
-    // either it is on a mut_list, or it isn't.  We adopt the convention that
-    // the closure type is MUT_ARR_PTRS_FROZEN0 if it is on the mutable list,
-    // and MUT_ARR_PTRS_FROZEN otherwise.  In fact it wouldn't matter if
-    // we put it on the mutable list more than once, but it would get scavenged
-    // multiple times during GC, which would be unnecessarily slow.
-    //
-    if (StgHeader_info(arr) != stg_MUT_ARR_PTRS_FROZEN0_info) {
+    // A MUT_ARR_PTRS always lives on a mut_list, but a MUT_ARR_PTRS_FROZEN
+    // doesn't. To decide whether to add the thawed array to a mut_list we check
+    // the info table. MUT_ARR_PTRS_FROZEN_DIRTY means it's already on a
+    // mut_list so no need to add it again. MUT_ARR_PTRS_FROZEN_CLEAN means it's
+    // not and we should add it to a mut_list.
+    if (StgHeader_info(arr) != stg_MUT_ARR_PTRS_FROZEN_DIRTY_info) {
         SET_INFO(arr,stg_MUT_ARR_PTRS_DIRTY_info);
+        // must be done after SET_INFO, because it ASSERTs closure_MUTABLE():
         recordMutable(arr);
-        // must be done after SET_INFO, because it ASSERTs closure_MUTABLE()
         return (arr);
     } else {
         SET_INFO(arr,stg_MUT_ARR_PTRS_DIRTY_info);
@@ -326,7 +313,7 @@ stg_copyMutableArrayArrayzh ( gcptr src, W_ src_off, gcptr dst, W_ dst_off, W_ n
 
 stg_cloneArrayzh ( gcptr src, W_ offset, W_ n )
 {
-    cloneArray(stg_MUT_ARR_PTRS_FROZEN_info, src, offset, n)
+    cloneArray(stg_MUT_ARR_PTRS_FROZEN_CLEAN_info, src, offset, n)
 }
 
 stg_cloneMutableArrayzh ( gcptr src, W_ offset, W_ n )
@@ -337,7 +324,7 @@ stg_cloneMutableArrayzh ( gcptr src, W_ offset, W_ n )
 // We have to escape the "z" in the name.
 stg_freezzeArrayzh ( gcptr src, W_ offset, W_ n )
 {
-    cloneArray(stg_MUT_ARR_PTRS_FROZEN_info, src, offset, n)
+    cloneArray(stg_MUT_ARR_PTRS_FROZEN_CLEAN_info, src, offset, n)
 }
 
 stg_thawArrayzh ( gcptr src, W_ offset, W_ n )
@@ -439,7 +426,7 @@ stg_newSmallArrayzh ( W_ n /* words */, gcptr init )
 stg_unsafeThawSmallArrayzh ( gcptr arr )
 {
     // See stg_unsafeThawArrayzh
-    if (StgHeader_info(arr) != stg_SMALL_MUT_ARR_PTRS_FROZEN0_info) {
+    if (StgHeader_info(arr) != stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY_info) {
         SET_INFO(arr, stg_SMALL_MUT_ARR_PTRS_DIRTY_info);
         recordMutable(arr);
         // must be done after SET_INFO, because it ASSERTs closure_MUTABLE()
@@ -452,7 +439,7 @@ stg_unsafeThawSmallArrayzh ( gcptr arr )
 
 stg_cloneSmallArrayzh ( gcptr src, W_ offset, W_ n )
 {
-    cloneSmallArray(stg_SMALL_MUT_ARR_PTRS_FROZEN_info, src, offset, n)
+    cloneSmallArray(stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN_info, src, offset, n)
 }
 
 stg_cloneSmallMutableArrayzh ( gcptr src, W_ offset, W_ n )
@@ -463,7 +450,7 @@ stg_cloneSmallMutableArrayzh ( gcptr src, W_ offset, W_ n )
 // We have to escape the "z" in the name.
 stg_freezzeSmallArrayzh ( gcptr src, W_ offset, W_ n )
 {
-    cloneSmallArray(stg_SMALL_MUT_ARR_PTRS_FROZEN_info, src, offset, n)
+    cloneSmallArray(stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN_info, src, offset, n)
 }
 
 stg_thawSmallArrayzh ( gcptr src, W_ offset, W_ n )
diff --git a/rts/Printer.c b/rts/Printer.c
index 01f16921cf..4019ef1710 100644
--- a/rts/Printer.c
+++ b/rts/Printer.c
@@ -308,8 +308,8 @@ printClosure( const StgClosure *obj )
         debugBelch("MUT_ARR_PTRS_DIRTY(size=%" FMT_Word ")\n", (W_)((StgMutArrPtrs *)obj)->ptrs);
         break;
 
-    case MUT_ARR_PTRS_FROZEN:
-        debugBelch("MUT_ARR_PTRS_FROZEN(size=%" FMT_Word ")\n", (W_)((StgMutArrPtrs *)obj)->ptrs);
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+        debugBelch("MUT_ARR_PTRS_FROZEN_CLEAN(size=%" FMT_Word ")\n", (W_)((StgMutArrPtrs *)obj)->ptrs);
         break;
 
     case SMALL_MUT_ARR_PTRS_CLEAN:
@@ -322,8 +322,8 @@ printClosure( const StgClosure *obj )
                    (W_)((StgSmallMutArrPtrs *)obj)->ptrs);
         break;
 
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-        debugBelch("SMALL_MUT_ARR_PTRS_FROZEN(size=%" FMT_Word ")\n",
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+        debugBelch("SMALL_MUT_ARR_PTRS_FROZEN_CLEAN(size=%" FMT_Word ")\n",
                    (W_)((StgSmallMutArrPtrs *)obj)->ptrs);
         break;
 
@@ -919,8 +919,8 @@ const char *closure_type_names[] = {
  [ARR_WORDS]             = "ARR_WORDS",
  [MUT_ARR_PTRS_CLEAN]    = "MUT_ARR_PTRS_CLEAN",
  [MUT_ARR_PTRS_DIRTY]    = "MUT_ARR_PTRS_DIRTY",
- [MUT_ARR_PTRS_FROZEN0]  = "MUT_ARR_PTRS_FROZEN0",
- [MUT_ARR_PTRS_FROZEN]   = "MUT_ARR_PTRS_FROZEN",
+ [MUT_ARR_PTRS_FROZEN_DIRTY]  = "MUT_ARR_PTRS_FROZEN_DIRTY",
+ [MUT_ARR_PTRS_FROZEN_CLEAN]   = "MUT_ARR_PTRS_FROZEN_CLEAN",
  [MUT_VAR_CLEAN]         = "MUT_VAR_CLEAN",
  [MUT_VAR_DIRTY]         = "MUT_VAR_DIRTY",
  [WEAK]                  = "WEAK",
@@ -935,8 +935,8 @@ const char *closure_type_names[] = {
  [WHITEHOLE]             = "WHITEHOLE",
  [SMALL_MUT_ARR_PTRS_CLEAN] = "SMALL_MUT_ARR_PTRS_CLEAN",
  [SMALL_MUT_ARR_PTRS_DIRTY] = "SMALL_MUT_ARR_PTRS_DIRTY",
- [SMALL_MUT_ARR_PTRS_FROZEN0] = "SMALL_MUT_ARR_PTRS_FROZEN0",
- [SMALL_MUT_ARR_PTRS_FROZEN] = "SMALL_MUT_ARR_PTRS_FROZEN",
+ [SMALL_MUT_ARR_PTRS_FROZEN_DIRTY] = "SMALL_MUT_ARR_PTRS_FROZEN_DIRTY",
+ [SMALL_MUT_ARR_PTRS_FROZEN_CLEAN] = "SMALL_MUT_ARR_PTRS_FROZEN_CLEAN",
  [COMPACT_NFDATA]        = "COMPACT_NFDATA"
 };
 
diff --git a/rts/ProfHeap.c b/rts/ProfHeap.c
index 55d22ff153..de3d2b6aa5 100644
--- a/rts/ProfHeap.c
+++ b/rts/ProfHeap.c
@@ -1093,16 +1093,16 @@ heapCensusChain( Census *census, bdescr *bd )
 
             case MUT_ARR_PTRS_CLEAN:
             case MUT_ARR_PTRS_DIRTY:
-            case MUT_ARR_PTRS_FROZEN:
-            case MUT_ARR_PTRS_FROZEN0:
+            case MUT_ARR_PTRS_FROZEN_CLEAN:
+            case MUT_ARR_PTRS_FROZEN_DIRTY:
                 prim = true;
                 size = mut_arr_ptrs_sizeW((StgMutArrPtrs *)p);
                 break;
 
             case SMALL_MUT_ARR_PTRS_CLEAN:
             case SMALL_MUT_ARR_PTRS_DIRTY:
-            case SMALL_MUT_ARR_PTRS_FROZEN:
-            case SMALL_MUT_ARR_PTRS_FROZEN0:
+            case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+            case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
                 prim = true;
                 size = small_mut_arr_ptrs_sizeW((StgSmallMutArrPtrs *)p);
                 break;
diff --git a/rts/RetainerProfile.c b/rts/RetainerProfile.c
index 0931d46a6d..b7c85e63cd 100644
--- a/rts/RetainerProfile.c
+++ b/rts/RetainerProfile.c
@@ -465,8 +465,8 @@ push( StgClosure *c, retainer c_child_r, StgClosure **first_child )
         // StgMutArrPtr.ptrs, no SRT
     case MUT_ARR_PTRS_CLEAN:
     case MUT_ARR_PTRS_DIRTY:
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
         init_ptrs(&se.info, ((StgMutArrPtrs *)c)->ptrs,
                   (StgPtr)(((StgMutArrPtrs *)c)->payload));
         *first_child = find_ptrs(&se.info);
@@ -477,8 +477,8 @@ push( StgClosure *c, retainer c_child_r, StgClosure **first_child )
         // StgMutArrPtr.ptrs, no SRT
     case SMALL_MUT_ARR_PTRS_CLEAN:
     case SMALL_MUT_ARR_PTRS_DIRTY:
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-    case SMALL_MUT_ARR_PTRS_FROZEN0:
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+    case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
         init_ptrs(&se.info, ((StgSmallMutArrPtrs *)c)->ptrs,
                   (StgPtr)(((StgSmallMutArrPtrs *)c)->payload));
         *first_child = find_ptrs(&se.info);
@@ -809,8 +809,8 @@ pop( StgClosure **c, StgClosure **cp, retainer *r )
             // StgMutArrPtr.ptrs, no SRT
         case MUT_ARR_PTRS_CLEAN:
         case MUT_ARR_PTRS_DIRTY:
-        case MUT_ARR_PTRS_FROZEN:
-        case MUT_ARR_PTRS_FROZEN0:
+        case MUT_ARR_PTRS_FROZEN_CLEAN:
+        case MUT_ARR_PTRS_FROZEN_DIRTY:
             *c = find_ptrs(&se->info);
             if (*c == NULL) {
                 popOff();
@@ -1031,10 +1031,10 @@ isRetainer( StgClosure *c )
         // STM
     case TREC_CHUNK:
         // immutable arrays
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-    case SMALL_MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+    case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
         return false;
 
         //
diff --git a/rts/RtsSymbols.c b/rts/RtsSymbols.c
index 783992b11a..87fa98dd4f 100644
--- a/rts/RtsSymbols.c
+++ b/rts/RtsSymbols.c
@@ -767,11 +767,11 @@
       SymI_HasProto(stg_IND_STATIC_info)                                \
       SymI_HasProto(stg_ARR_WORDS_info)                                 \
       SymI_HasProto(stg_MUT_ARR_PTRS_DIRTY_info)                        \
-      SymI_HasProto(stg_MUT_ARR_PTRS_FROZEN_info)                       \
-      SymI_HasProto(stg_MUT_ARR_PTRS_FROZEN0_info)                      \
+      SymI_HasProto(stg_MUT_ARR_PTRS_FROZEN_CLEAN_info)                 \
+      SymI_HasProto(stg_MUT_ARR_PTRS_FROZEN_DIRTY_info)                 \
       SymI_HasProto(stg_SMALL_MUT_ARR_PTRS_DIRTY_info)                  \
-      SymI_HasProto(stg_SMALL_MUT_ARR_PTRS_FROZEN_info)                 \
-      SymI_HasProto(stg_SMALL_MUT_ARR_PTRS_FROZEN0_info)                \
+      SymI_HasProto(stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN_info)           \
+      SymI_HasProto(stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY_info)           \
       SymI_HasProto(stg_MUT_VAR_CLEAN_info)                             \
       SymI_HasProto(stg_MUT_VAR_DIRTY_info)                             \
       SymI_HasProto(stg_WEAK_info)                                      \
diff --git a/rts/StgMiscClosures.cmm b/rts/StgMiscClosures.cmm
index 3add25e219..e645442033 100644
--- a/rts/StgMiscClosures.cmm
+++ b/rts/StgMiscClosures.cmm
@@ -633,11 +633,11 @@ INFO_TABLE(stg_MUT_ARR_PTRS_CLEAN, 0, 0, MUT_ARR_PTRS_CLEAN, "MUT_ARR_PTRS_CLEAN
 INFO_TABLE(stg_MUT_ARR_PTRS_DIRTY, 0, 0, MUT_ARR_PTRS_DIRTY, "MUT_ARR_PTRS_DIRTY", "MUT_ARR_PTRS_DIRTY")
 { foreign "C" barf("MUT_ARR_PTRS_DIRTY object entered!") never returns; }
 
-INFO_TABLE(stg_MUT_ARR_PTRS_FROZEN, 0, 0, MUT_ARR_PTRS_FROZEN, "MUT_ARR_PTRS_FROZEN", "MUT_ARR_PTRS_FROZEN")
-{ foreign "C" barf("MUT_ARR_PTRS_FROZEN object entered!") never returns; }
+INFO_TABLE(stg_MUT_ARR_PTRS_FROZEN_CLEAN, 0, 0, MUT_ARR_PTRS_FROZEN_CLEAN, "MUT_ARR_PTRS_FROZEN_CLEAN", "MUT_ARR_PTRS_FROZEN_CLEAN")
+{ foreign "C" barf("MUT_ARR_PTRS_FROZEN_CLEAN object entered!") never returns; }
 
-INFO_TABLE(stg_MUT_ARR_PTRS_FROZEN0, 0, 0, MUT_ARR_PTRS_FROZEN0, "MUT_ARR_PTRS_FROZEN0", "MUT_ARR_PTRS_FROZEN0")
-{ foreign "C" barf("MUT_ARR_PTRS_FROZEN0 object entered!") never returns; }
+INFO_TABLE(stg_MUT_ARR_PTRS_FROZEN_DIRTY, 0, 0, MUT_ARR_PTRS_FROZEN_DIRTY, "MUT_ARR_PTRS_FROZEN_DIRTY", "MUT_ARR_PTRS_FROZEN_DIRTY")
+{ foreign "C" barf("MUT_ARR_PTRS_FROZEN_DIRTY object entered!") never returns; }
 
 INFO_TABLE(stg_SMALL_MUT_ARR_PTRS_CLEAN, 0, 0, SMALL_MUT_ARR_PTRS_CLEAN, "SMALL_MUT_ARR_PTRS_CLEAN", "SMALL_MUT_ARR_PTRS_CLEAN")
 { foreign "C" barf("SMALL_MUT_ARR_PTRS_CLEAN object entered!") never returns; }
@@ -645,11 +645,11 @@ INFO_TABLE(stg_SMALL_MUT_ARR_PTRS_CLEAN, 0, 0, SMALL_MUT_ARR_PTRS_CLEAN, "SMALL_
 INFO_TABLE(stg_SMALL_MUT_ARR_PTRS_DIRTY, 0, 0, SMALL_MUT_ARR_PTRS_DIRTY, "SMALL_MUT_ARR_PTRS_DIRTY", "SMALL_MUT_ARR_PTRS_DIRTY")
 { foreign "C" barf("SMALL_MUT_ARR_PTRS_DIRTY object entered!") never returns; }
 
-INFO_TABLE(stg_SMALL_MUT_ARR_PTRS_FROZEN, 0, 0, SMALL_MUT_ARR_PTRS_FROZEN, "SMALL_MUT_ARR_PTRS_FROZEN", "SMALL_MUT_ARR_PTRS_FROZEN")
-{ foreign "C" barf("SMALL_MUT_ARR_PTRS_FROZEN object entered!") never returns; }
+INFO_TABLE(stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN, 0, 0, SMALL_MUT_ARR_PTRS_FROZEN_CLEAN, "SMALL_MUT_ARR_PTRS_FROZEN_CLEAN", "SMALL_MUT_ARR_PTRS_FROZEN_CLEAN")
+{ foreign "C" barf("SMALL_MUT_ARR_PTRS_FROZEN_CLEAN object entered!") never returns; }
 
-INFO_TABLE(stg_SMALL_MUT_ARR_PTRS_FROZEN0, 0, 0, SMALL_MUT_ARR_PTRS_FROZEN0, "SMALL_MUT_ARR_PTRS_FROZEN0", "SMALL_MUT_ARR_PTRS_FROZEN0")
-{ foreign "C" barf("SMALL_MUT_ARR_PTRS_FROZEN0 object entered!") never returns; }
+INFO_TABLE(stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY, 0, 0, SMALL_MUT_ARR_PTRS_FROZEN_DIRTY, "SMALL_MUT_ARR_PTRS_FROZEN_DIRTY", "SMALL_MUT_ARR_PTRS_FROZEN_DIRTY")
+{ foreign "C" barf("SMALL_MUT_ARR_PTRS_FROZEN_DIRTY object entered!") never returns; }
 
 /* ----------------------------------------------------------------------------
    Mutable Variables
diff --git a/rts/Weak.c b/rts/Weak.c
index 80623409b5..a322d822af 100644
--- a/rts/Weak.c
+++ b/rts/Weak.c
@@ -138,7 +138,7 @@ scheduleFinalizers(Capability *cap, StgWeak *list)
     size = n + mutArrPtrsCardTableSize(n);
     arr = (StgMutArrPtrs *)allocate(cap, sizeofW(StgMutArrPtrs) + size);
     TICK_ALLOC_PRIM(sizeofW(StgMutArrPtrs), n, 0);
-    SET_HDR(arr, &stg_MUT_ARR_PTRS_FROZEN_info, CCS_SYSTEM);
+    SET_HDR(arr, &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info, CCS_SYSTEM);
     arr->ptrs = n;
     arr->size = size;
 
diff --git a/rts/sm/CNF.c b/rts/sm/CNF.c
index c12f53a120..6bc58cde75 100644
--- a/rts/sm/CNF.c
+++ b/rts/sm/CNF.c
@@ -722,14 +722,14 @@ verify_consistency_block (StgCompactNFData *str, StgCompactNFDataBlock *block)
             p += arr_words_sizeW((StgArrBytes*)p);
             break;
 
-        case MUT_ARR_PTRS_FROZEN:
-        case MUT_ARR_PTRS_FROZEN0:
+        case MUT_ARR_PTRS_FROZEN_CLEAN:
+        case MUT_ARR_PTRS_FROZEN_DIRTY:
             verify_mut_arr_ptrs(str, (StgMutArrPtrs*)p);
             p += mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
             break;
 
-        case SMALL_MUT_ARR_PTRS_FROZEN:
-        case SMALL_MUT_ARR_PTRS_FROZEN0:
+        case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+        case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
         {
             uint32_t i;
             StgSmallMutArrPtrs *arr = (StgSmallMutArrPtrs*)p;
@@ -969,14 +969,14 @@ fixup_block(StgCompactNFDataBlock *block, StgWord *fixup_table, uint32_t count)
             p += arr_words_sizeW((StgArrBytes*)p);
             break;
 
-        case MUT_ARR_PTRS_FROZEN:
-        case MUT_ARR_PTRS_FROZEN0:
+        case MUT_ARR_PTRS_FROZEN_CLEAN:
+        case MUT_ARR_PTRS_FROZEN_DIRTY:
             fixup_mut_arr_ptrs(fixup_table, count, (StgMutArrPtrs*)p);
             p += mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
             break;
 
-        case SMALL_MUT_ARR_PTRS_FROZEN:
-        case SMALL_MUT_ARR_PTRS_FROZEN0:
+        case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+        case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
         {
             uint32_t i;
             StgSmallMutArrPtrs *arr = (StgSmallMutArrPtrs*)p;
diff --git a/rts/sm/Compact.c b/rts/sm/Compact.c
index f252e89161..10ad73c7d7 100644
--- a/rts/sm/Compact.c
+++ b/rts/sm/Compact.c
@@ -482,8 +482,8 @@ update_fwd_large( bdescr *bd )
 
     case MUT_ARR_PTRS_CLEAN:
     case MUT_ARR_PTRS_DIRTY:
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
       // follow everything
       {
           StgMutArrPtrs *a;
@@ -497,8 +497,8 @@ update_fwd_large( bdescr *bd )
 
     case SMALL_MUT_ARR_PTRS_CLEAN:
     case SMALL_MUT_ARR_PTRS_DIRTY:
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-    case SMALL_MUT_ARR_PTRS_FROZEN0:
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+    case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
       // follow everything
       {
           StgSmallMutArrPtrs *a;
@@ -682,8 +682,8 @@ thread_obj (const StgInfoTable *info, StgPtr p)
 
     case MUT_ARR_PTRS_CLEAN:
     case MUT_ARR_PTRS_DIRTY:
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
         // follow everything
     {
         StgMutArrPtrs *a;
@@ -698,8 +698,8 @@ thread_obj (const StgInfoTable *info, StgPtr p)
 
     case SMALL_MUT_ARR_PTRS_CLEAN:
     case SMALL_MUT_ARR_PTRS_DIRTY:
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-    case SMALL_MUT_ARR_PTRS_FROZEN0:
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+    case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
         // follow everything
     {
         StgSmallMutArrPtrs *a;
diff --git a/rts/sm/Evac.c b/rts/sm/Evac.c
index e8baebe553..3415a4ace1 100644
--- a/rts/sm/Evac.c
+++ b/rts/sm/Evac.c
@@ -825,16 +825,16 @@ loop:
 
   case MUT_ARR_PTRS_CLEAN:
   case MUT_ARR_PTRS_DIRTY:
-  case MUT_ARR_PTRS_FROZEN:
-  case MUT_ARR_PTRS_FROZEN0:
+  case MUT_ARR_PTRS_FROZEN_CLEAN:
+  case MUT_ARR_PTRS_FROZEN_DIRTY:
       // just copy the block
       copy(p,info,q,mut_arr_ptrs_sizeW((StgMutArrPtrs *)q),gen_no);
       return;
 
   case SMALL_MUT_ARR_PTRS_CLEAN:
   case SMALL_MUT_ARR_PTRS_DIRTY:
-  case SMALL_MUT_ARR_PTRS_FROZEN:
-  case SMALL_MUT_ARR_PTRS_FROZEN0:
+  case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+  case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
       // just copy the block
       copy(p,info,q,small_mut_arr_ptrs_sizeW((StgSmallMutArrPtrs *)q),gen_no);
       return;
diff --git a/rts/sm/Sanity.c b/rts/sm/Sanity.c
index defefa3f01..81e692240d 100644
--- a/rts/sm/Sanity.c
+++ b/rts/sm/Sanity.c
@@ -380,8 +380,8 @@ checkClosure( const StgClosure* p )
 
     case MUT_ARR_PTRS_CLEAN:
     case MUT_ARR_PTRS_DIRTY:
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
         {
             StgMutArrPtrs* a = (StgMutArrPtrs *)p;
             uint32_t i;
diff --git a/rts/sm/Scav.c b/rts/sm/Scav.c
index 72411bc975..26687b880a 100644
--- a/rts/sm/Scav.c
+++ b/rts/sm/Scav.c
@@ -646,18 +646,16 @@ scavenge_block (bdescr *bd)
         break;
     }
 
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
         // follow everything
     {
         p = scavenge_mut_arr_ptrs((StgMutArrPtrs*)p);
 
-        // If we're going to put this object on the mutable list, then
-        // set its info ptr to MUT_ARR_PTRS_FROZEN0 to indicate that.
         if (gct->failed_to_evac) {
-            ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN0_info;
+            ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN_DIRTY_info;
         } else {
-            ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN_info;
+            ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info;
         }
         break;
     }
@@ -689,8 +687,8 @@ scavenge_block (bdescr *bd)
         break;
     }
 
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-    case SMALL_MUT_ARR_PTRS_FROZEN0:
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+    case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
         // follow everything
     {
         StgPtr next;
@@ -700,12 +698,10 @@ scavenge_block (bdescr *bd)
             evacuate((StgClosure **)p);
         }
 
-        // If we're going to put this object on the mutable list, then
-        // set its info ptr to SMALL_MUT_ARR_PTRS_FROZEN0 to indicate that.
         if (gct->failed_to_evac) {
-            ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN0_info;
+            ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY_info;
         } else {
-            ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_info;
+            ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN_info;
         }
         break;
     }
@@ -1042,20 +1038,18 @@ scavenge_mark_stack(void)
             break;
         }
 
-        case MUT_ARR_PTRS_FROZEN:
-        case MUT_ARR_PTRS_FROZEN0:
+        case MUT_ARR_PTRS_FROZEN_CLEAN:
+        case MUT_ARR_PTRS_FROZEN_DIRTY:
             // follow everything
         {
             StgPtr q = p;
 
             scavenge_mut_arr_ptrs((StgMutArrPtrs *)p);
 
-            // If we're going to put this object on the mutable list, then
-            // set its info ptr to MUT_ARR_PTRS_FROZEN0 to indicate that.
             if (gct->failed_to_evac) {
-                ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN0_info;
+                ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN_DIRTY_info;
             } else {
-                ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN_info;
+                ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info;
             }
             break;
         }
@@ -1089,8 +1083,8 @@ scavenge_mark_stack(void)
             break;
         }
 
-        case SMALL_MUT_ARR_PTRS_FROZEN:
-        case SMALL_MUT_ARR_PTRS_FROZEN0:
+        case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+        case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
             // follow everything
         {
             StgPtr next, q = p;
@@ -1100,12 +1094,10 @@ scavenge_mark_stack(void)
                 evacuate((StgClosure **)p);
             }
 
-            // If we're going to put this object on the mutable list, then
-            // set its info ptr to SMALL_MUT_ARR_PTRS_FROZEN0 to indicate that.
             if (gct->failed_to_evac) {
-                ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN0_info;
+                ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY_info;
             } else {
-                ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_info;
+                ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN_info;
             }
             break;
         }
@@ -1366,18 +1358,16 @@ scavenge_one(StgPtr p)
         break;
     }
 
-    case MUT_ARR_PTRS_FROZEN:
-    case MUT_ARR_PTRS_FROZEN0:
+    case MUT_ARR_PTRS_FROZEN_CLEAN:
+    case MUT_ARR_PTRS_FROZEN_DIRTY:
     {
         // follow everything
         scavenge_mut_arr_ptrs((StgMutArrPtrs *)p);
 
-        // If we're going to put this object on the mutable list, then
-        // set its info ptr to MUT_ARR_PTRS_FROZEN0 to indicate that.
         if (gct->failed_to_evac) {
-            ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_FROZEN0_info;
+            ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_FROZEN_DIRTY_info;
         } else {
-            ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_FROZEN_info;
+            ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_FROZEN_CLEAN_info;
         }
         break;
     }
@@ -1411,8 +1401,8 @@ scavenge_one(StgPtr p)
         break;
     }
 
-    case SMALL_MUT_ARR_PTRS_FROZEN:
-    case SMALL_MUT_ARR_PTRS_FROZEN0:
+    case SMALL_MUT_ARR_PTRS_FROZEN_CLEAN:
+    case SMALL_MUT_ARR_PTRS_FROZEN_DIRTY:
     {
         // follow everything
         StgPtr next, q=p;
@@ -1422,12 +1412,10 @@ scavenge_one(StgPtr p)
             evacuate((StgClosure **)p);
         }
 
-        // If we're going to put this object on the mutable list, then
-        // set its info ptr to SMALL_MUT_ARR_PTRS_FROZEN0 to indicate that.
         if (gct->failed_to_evac) {
-            ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN0_info;
+            ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_DIRTY_info;
         } else {
-            ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_info;
+            ((StgClosure *)q)->header.info = &stg_SMALL_MUT_ARR_PTRS_FROZEN_CLEAN_info;
         }
         break;
     }
@@ -1562,8 +1550,8 @@ scavenge_mutable_list(bdescr *bd, generation *gen)
                 mutlist_MUTVARS++; break;
             case MUT_ARR_PTRS_CLEAN:
             case MUT_ARR_PTRS_DIRTY:
-            case MUT_ARR_PTRS_FROZEN:
-            case MUT_ARR_PTRS_FROZEN0:
+            case MUT_ARR_PTRS_FROZEN_CLEAN:
+            case MUT_ARR_PTRS_FROZEN_DIRTY:
                 mutlist_MUTARRS++; break;
             case MVAR_CLEAN:
                 barf("MVAR_CLEAN on mutable list");