Fix BIGNUM_REDUCE_LENGTH to hide the unused (non-marked) words.

This quiets 7093 of the 7110 complaints from verify_heap during the
tests.

diff --git a/src/microcode/bignmint.h b/src/microcode/bignmint.h
index 7700259c5b1be215de3d28d2c51dd5f9992c4598..e644716b0b566215995c967ca72a0b632ced40de 100644 (file)
--- a/src/microcode/bignmint.h
+++ b/src/microcode/bignmint.h
@@ -56,8 +56,18 @@ typedef long bignum_length_type;
    space when a bignum's length is reduced from its original value. */
 #define BIGNUM_REDUCE_LENGTH(target, source, length)                   \
 {                                                                      \
-  SET_VECTOR_LENGTH ((source), (BIGNUM_LENGTH_TO_GC_LENGTH (length))); \
-  (target) = (source);                                                 \
+  int new_gc_length = BIGNUM_LENGTH_TO_GC_LENGTH (length);             \
+  int old_gc_length = VECTOR_LENGTH (source);                          \
+  int delta = old_gc_length - new_gc_length;                           \
+  assert (delta >= 0);                                                 \
+  assert ((target) == (source));                                       \
+  if (delta == 1)                                                      \
+    VECTOR_SET (source, new_gc_length, SHARP_F);                       \
+  else if (delta > 1)                                                  \
+    VECTOR_SET (source, new_gc_length,                                 \
+               (MAKE_OBJECT (TC_MANIFEST_NM_VECTOR, delta - 1)));      \
+  if (delta != 0)                                                      \
+    SET_VECTOR_LENGTH (source, new_gc_length);                         \
 }
 
 #define BIGNUM_LENGTH_TO_GC_LENGTH(length)                             \