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/Messages.c b/rts/Messages.c
index 6a09cd898b..89415ea3d6 100644
--- a/rts/Messages.c
+++ b/rts/Messages.c
@@ -257,7 +257,7 @@ loop:
         // point to the BLOCKING_QUEUE from the BLACKHOLE
         write_barrier(); // make the BQ visible
         if (nonmoving_write_barrier_enabled) {
-            updateRemembSetPushClosure(cap, (StgClosure*)p, NULL);
+            updateRemembSetPushClosure(cap, (StgClosure*)p);
         }
         ((StgInd*)bh)->indirectee = (StgClosure *)bq;
         recordClosureMutated(cap,bh); // bh was mutated
@@ -290,7 +290,7 @@ loop:
         if (nonmoving_write_barrier_enabled) {
             // We are about to overwrite bq->queue; make sure its current value
             // makes it into the update remembered set
-            updateRemembSetPushClosure(cap, (StgClosure*)bq->queue, NULL);
+            updateRemembSetPushClosure(cap, (StgClosure*)bq->queue);
         }
         msg->link = bq->queue;
         bq->queue = msg;