Do not do unnecessary GC_read_dirty() from GC_enable_incremental

* misc.c [!GC_DISABLE_INCREMENTAL && !KEEP_BACK_PTRS]
(GC_enable_incremental): Do not call GC_read_dirty() if GC_bytes_allocd
is non-zero.
* misc.c [!GC_DISABLE_INCREMENTAL && !KEEP_BACK_PTRS && !CHECKSUMS]
(GC_enable_incremental): Pass TRUE (output_unneeded) to
GC_read_dirty().

1 files changed, 8 insertions, 3 deletions

diff --git a/misc.c b/misc.c
index e6005fd8..3b6dda83 100644
--- a/misc.c
+++ b/misc.c
@@ -1437,11 +1437,16 @@ GC_API void GC_CALL GC_enable_incremental(void)
           if (GC_bytes_allocd > 0) {
             /* There may be unmarked reachable objects. */
             GC_gcollect_inner();
-          }
-            /* else we're OK in assuming everything's   */
+          } else {
+            /* We are OK in assuming everything is      */
             /* clean since nothing can point to an      */
             /* unmarked object.                         */
-          GC_read_dirty(FALSE);
+#           ifdef CHECKSUMS
+              GC_read_dirty(FALSE);
+#           else
+              GC_read_dirty(TRUE);
+#           endif
+          }
           RESTORE_CANCEL(cancel_state);
         }
       }