Check highest bit of word using SIGNB instead of cast to signed_word

(refactoring)

* allchblk.c (GC_merge_unmapped): Replace overflow check
(signed_word)(sz1+sz2)>0 to !((sz1+sz2)&SIGNB).
* allchblk.c (GC_freehblk): Likewise.
* mark.c (GC_mark_from): Replace (signed_word)descr>=0 expression
to !(descr&SIGNB).
* ptr_chck.c (GC_is_visible): Likewise.

1 files changed, 1 insertions, 1 deletions

diff --git a/mark.c b/mark.c
index ae8f314f..9f9027d0 100644
--- a/mark.c
+++ b/mark.c
@@ -678,7 +678,7 @@ GC_INNER mse * GC_mark_from(mse *mark_stack_top, mse *mark_stack,
                                           mark_stack_limit, ENV(descr));
           continue;
         case GC_DS_PER_OBJECT:
-          if ((signed_word)descr >= 0) {
+          if (!(descr & SIGNB)) {
             /* Descriptor is in the object.     */
             descr = *(word *)(current_p + descr - GC_DS_PER_OBJECT);
           } else {