hash: fix: equal hashes being reduced modulo NUM_MAX.

Almost exactly 6 years ago, commit 855fbd81c made hashes
use the full width of the ucnum type. However, several
reductions of the form hash &= NUM_MAX were forgotten.

* hash.c (hash_hash_op): Eliminate reductions modulo NUM_MAX.

* struct.c (struct_inst_hash): Likewise.

2 files changed, 1 insertions, 5 deletions

diff --git a/hash.c b/hash.c
index 58732193..43763983 100644
--- a/hash.c
+++ b/hash.c
@@ -775,14 +775,11 @@ static ucnum hash_hash_op(val obj, int *count, ucnum seed)
   }
 
   out += equal_hash(h->userdata, count, seed);
-  out &= NUM_MAX;
 
   us_hash_iter_init(&hi, obj);
 
-  while ((*count)-- > 0 && (cell = hash_iter_next(&hi)) != nil) {
+  while ((*count)-- > 0 && (cell = hash_iter_next(&hi)) != nil)
     out += equal_hash(cell, count, seed);
-    out &= NUM_MAX;
-  }
 
   return out;
 }
diff --git a/struct.c b/struct.c
index b421a265..a449e9d7 100644
--- a/struct.c
+++ b/struct.c
@@ -1870,7 +1870,6 @@ static ucnum struct_inst_hash(val obj, int *count, ucnum seed)
   for (sl = 0; sl < nslots; sl++) {
     ucnum hash = equal_hash(si->slot[sl], count, seed);
     out += hash;
-    out &= NUM_MAX;
   }
 
   return out;