Check pointer tag in all mark procedures (E2K)

Issue #411 (bdwgc).

Do not mark objects if its pointer tag is non-zero, not only in
GC_mark_from and GC_push_all_eager, but also in add_back_edges,
GC_ignore_self_finalize_mark_proc, GC_typed_mark_proc and
GC_push_conditional_eager.

* backgraph.c [MAKE_BACK_GRAPH] (add_back_edges): Change type of
current_p local variable from word* to ptr_t.
* typd_mlc.c (GC_typed_mark_proc): Likewise.
* backgraph.c [MAKE_BACK_GRAPH] (add_back_edges): Use
LOAD_WORD_OR_CONTINUE() instead of direct dereference of current_p.
* finalize.c (GC_ignore_self_finalize_mark_proc): Likewise.
* mark.c [WRAP_MARK_SOME && PARALLEL_MARK] (GC_push_conditional_eager):
Likewise.
* typd_mlc.c (GC_typed_mark_proc): Likewise.
* finalize.c (GC_ignore_self_finalize_mark_proc): Rename q and r local
variables to current_p and q, respectively.

1 files changed, 6 insertions, 5 deletions

diff --git a/typd_mlc.c b/typd_mlc.c
index fb8990c6..4078e189 100644
--- a/typd_mlc.c
+++ b/typd_mlc.c
@@ -344,20 +344,21 @@ STATIC mse * GC_typed_mark_proc(word * addr, mse * mark_stack_ptr,
                                 mse * mark_stack_limit, word env)
 {
     word bm = GC_ext_descriptors[env].ed_bitmap;
-    word * current_p = addr;
-    word current;
+    ptr_t current_p = (ptr_t)addr;
     ptr_t greatest_ha = (ptr_t)GC_greatest_plausible_heap_addr;
     ptr_t least_ha = (ptr_t)GC_least_plausible_heap_addr;
     DECLARE_HDR_CACHE;
 
     INIT_HDR_CACHE;
-    for (; bm != 0; bm >>= 1, current_p++) {
+    for (; bm != 0; bm >>= 1, current_p += sizeof(word)) {
         if (bm & 1) {
-            current = *current_p;
+            word current;
+
+            LOAD_WORD_OR_CONTINUE(current, current_p);
             FIXUP_POINTER(current);
             if (current >= (word)least_ha && current <= (word)greatest_ha) {
                 PUSH_CONTENTS((ptr_t)current, mark_stack_ptr,
-                              mark_stack_limit, (ptr_t)current_p);
+                              mark_stack_limit, current_p);
             }
         }
     }