an LDV profiling fix (might just fix ASSERTIONs, I'm not sure)

diff --git a/ghc/rts/GC.c b/ghc/rts/GC.c
index 8a3b54e..9aee2bc 100644 (file)
--- a/ghc/rts/GC.c
+++ b/ghc/rts/GC.c
@@ -2016,11 +2016,15 @@ loop:
   case THUNK_SELECTOR:
     {
        StgClosure *p;
+       const StgInfoTable *info_ptr;
 
        if (thunk_selector_depth > MAX_THUNK_SELECTOR_DEPTH) {
            return copy(q,THUNK_SELECTOR_sizeW(),stp);
        }
 
+       // stashed away for LDV profiling, see below
+       info_ptr = q->header.info;
+
        p = eval_thunk_selector(info->layout.selector_offset,
                                (StgSelector *)q);
 
@@ -2033,6 +2037,13 @@ loop:
            val = evacuate(p);
            thunk_selector_depth--;
 
+#ifdef PROFILING
+           // For the purposes of LDV profiling, we have destroyed
+           // the original selector thunk.
+           SET_INFO(q, info_ptr);
+           LDV_RECORD_DEAD_FILL_SLOP_DYNAMIC(q);
+#endif
+
            // Update the THUNK_SELECTOR with an indirection to the
            // EVACUATED closure now at p.  Why do this rather than
            // upd_evacuee(q,p)?  Because we have an invariant that an
@@ -2042,12 +2053,10 @@ loop:
            SET_INFO(q, &stg_IND_info);
            ((StgInd *)q)->indirectee = p;
 
-#ifdef PROFILING
-           // We store the size of the just evacuated object in the
-           // LDV word so that the profiler can guess the position of
-           // the next object later.
-           SET_EVACUAEE_FOR_LDV(q, THUNK_SELECTOR_sizeW());
-#endif
+           // For the purposes of LDV profiling, we have created an
+           // indirection.
+           LDV_RECORD_CREATE(q);
+
            return val;
        }
     }