Remove origin arguments from write barrier functionswip/nonmoving-gc

Write barriers push old values of updated field, e.g. when we have

    *q = p;

we do

    updateRemembSetPushClosure(*q, q);
    *q = p;

Here the second argument ("origin") is not useful because by the time we
do the update we invalidate "origin" (`q` is no longer origin of old
`*q`).

In general it doesn't make sense to record origins in write barriers so
we remove all origin arguments from write barriers.

Fixes #170.

1 files changed, 2 insertions, 2 deletions

diff --git a/rts/STM.c b/rts/STM.c
index c78229e74d..9176f66e72 100644
--- a/rts/STM.c
+++ b/rts/STM.c
@@ -298,7 +298,7 @@ static StgClosure *lock_tvar(Capability *cap,
                (StgWord)result, (StgWord)trec) != (StgWord)result);
 
   if (nonmoving_write_barrier_enabled && result) {
-      updateRemembSetPushClosure(cap, result, NULL);
+      updateRemembSetPushClosure(cap, result);
   }
   return result;
 }
@@ -324,7 +324,7 @@ static StgBool cond_lock_tvar(Capability *cap,
   w = cas((void *)&(s -> current_value), (StgWord)expected, (StgWord)trec);
   result = (StgClosure *)w;
   if (nonmoving_write_barrier_enabled && result) {
-      updateRemembSetPushClosure(cap, expected, NULL);
+      updateRemembSetPushClosure(cap, expected);
   }
   TRACE("%p : %s", trec, result ? "success" : "failure");
   return (result == expected);