update submodules for GHC.HetMet.GArrow -> Control.GArrow renaming

[ghc-hetmet.git] / rts / Updates.cmm

diff --git a/rts/Updates.cmm b/rts/Updates.cmm
index fadf63b..789bdd5 100644 (file)
--- a/rts/Updates.cmm
+++ b/rts/Updates.cmm
@@ -16,10 +16,11 @@
 
 #include "Updates.h"
 
-/* on entry to the update code
-   (1) R1 points to the closure being returned
-   (2) Sp points to the update frame
-*/
+#if defined(PROFILING)
+#define UPD_FRAME_PARAMS W_ unused1, W_ unused2, P_ unused3
+#else
+#define UPD_FRAME_PARAMS P_ unused1
+#endif
 
 /* The update fragment has been tuned so as to generate good
    code with gcc, which accounts for some of the strangeness in the
@@ -30,35 +31,69 @@
    code), since we don't mind duplicating this jump.
 */
 
-#define UPD_FRAME_ENTRY_TEMPLATE                                       \
-       {                                                               \
-          W_ updatee;                                                  \
-                                                                       \
-          updatee = StgUpdateFrame_updatee(Sp);                                \
-                                                                       \
-         /* remove the update frame from the stack */                  \
-         Sp = Sp + SIZEOF_StgUpdateFrame;                              \
-                                                                       \
-         /* ToDo: it might be a PAP, so we should check... */          \
-         TICK_UPD_CON_IN_NEW(sizeW_fromITBL(%GET_STD_INFO(updatee)));  \
-                                                                       \
-         UPD_SPEC_IND(updatee, stg_IND_direct_info, R1, jump %ENTRY_CODE(Sp(0))); \
-       }
-
-#if defined(PROFILING)
-#define UPD_FRAME_PARAMS W_ unused1, W_ unused2, P_ unused3
-#else
-#define UPD_FRAME_PARAMS P_ unused1
-#endif
-
-/* this bitmap indicates that the first word of an update frame is a
- * non-pointer - this is the update frame link.  (for profiling,
- * there's a cost-centre-stack in there too).
- */
+/* on entry to the update code
+   (1) R1 points to the closure being returned
+   (2) Sp points to the update frame
+*/
 
 INFO_TABLE_RET( stg_upd_frame, UPDATE_FRAME, UPD_FRAME_PARAMS)
-UPD_FRAME_ENTRY_TEMPLATE
+{
+    W_ updatee;
+    
+    updatee = StgUpdateFrame_updatee(Sp);
+    
+    /* remove the update frame from the stack */
+    Sp = Sp + SIZEOF_StgUpdateFrame;
+    
+    /* ToDo: it might be a PAP, so we should check... */
+    TICK_UPD_CON_IN_NEW(sizeW_fromITBL(%GET_STD_INFO(updatee)));
+    
+    updateWithIndirection(updatee,
+                          R1,
+                          jump %ENTRY_CODE(Sp(0)));
+}
 
 
 INFO_TABLE_RET( stg_marked_upd_frame, UPDATE_FRAME, UPD_FRAME_PARAMS)
-UPD_FRAME_ENTRY_TEMPLATE
+{
+    W_ updatee, v, i, tso, link;
+
+    // we know the closure is a BLACKHOLE
+    updatee = StgUpdateFrame_updatee(Sp);
+    v = StgInd_indirectee(updatee);
+
+    // remove the update frame from the stack
+    Sp = Sp + SIZEOF_StgUpdateFrame;
+    
+    if (GETTAG(v) != 0) {
+        // updated by someone else: discard our value and use the
+        // other one to increase sharing, but check the blocking
+        // queues to see if any threads were waiting on this BLACKHOLE.
+        R1 = v;
+        foreign "C" checkBlockingQueues(MyCapability() "ptr",
+                                        CurrentTSO "ptr") [R1];
+        jump %ENTRY_CODE(Sp(0));
+    }
+
+    // common case: it is still our BLACKHOLE
+    if (v == CurrentTSO) {
+        updateWithIndirection(updatee,
+                              R1,
+                              jump %ENTRY_CODE(Sp(0)));
+    }
+
+    // The other cases are all handled by the generic code
+    foreign "C" updateThunk (MyCapability() "ptr", CurrentTSO "ptr", 
+                             updatee "ptr", R1 "ptr") [R1];
+
+    jump %ENTRY_CODE(Sp(0));
+}
+
+// Special update frame code for CAFs and eager-blackholed thunks: it
+// knows how to update blackholes, but is distinct from
+// stg_marked_upd_frame so that lazy blackholing won't treat it as the
+// high watermark.
+INFO_TABLE_RET (stg_bh_upd_frame, UPDATE_FRAME, UPD_FRAME_PARAMS)
+{
+    jump RET_LBL(stg_marked_upd_frame);
+}