A boxed Integer's &, | and ^ keep a Bignum operand's width

lib/spinel_rt.h

@@ -7547,6 +7547,12 @@ static int sp_poly_both_arrays(sp_RbVal a, sp_RbVal b) {
   return a.tag == SP_TAG_OBJ && sp_poly_is_array_kind(a.cls_id) &&
          b.tag == SP_TAG_OBJ && sp_poly_is_array_kind(b.cls_id);
 }
+/* Two Integers, one of them a Bignum: sp_poly_bitop keeps the width, where
+   the int64 arm below cut `28 | 2**64` to 28. */
+static int sp_poly_bitop_wide(sp_RbVal a, sp_RbVal b) {
+  return (a.tag == SP_TAG_INT && b.tag == SP_TAG_BIGINT) ||
+         (a.tag == SP_TAG_BIGINT && (b.tag == SP_TAG_INT || b.tag == SP_TAG_BIGINT));
+}
 static sp_RbVal sp_poly_band(sp_RbVal a, sp_RbVal b) {
   if (a.tag == SP_TAG_NIL) return sp_box_bool(0);
   if (a.tag == SP_TAG_BOOL) return sp_box_bool(a.v.b && sp_poly_truthy(b));
@@ -7559,6 +7565,7 @@ static sp_RbVal sp_poly_band(sp_RbVal a, sp_RbVal b) {
   if (sp_poly_is_user_obj(a)) return sp_poly_binop_bad("&", a, b);
   /* Integer#& is Integer's alone (see sp_poly_bitop) */
   if (a.tag != SP_TAG_INT && a.tag != SP_TAG_BIGINT) return sp_poly_binop_bad("&", a, b);
+  if (sp_poly_bitop_wide(a, b)) return sp_poly_bitop(a, b, 0);
   return sp_box_int(sp_poly_to_i(a) & sp_poly_bit_operand(b, 0));
 }
 static sp_RbVal sp_poly_bor(sp_RbVal a, sp_RbVal b) {
@@ -7573,6 +7580,7 @@ static sp_RbVal sp_poly_bor(sp_RbVal a, sp_RbVal b) {
   if (sp_poly_is_user_obj(a)) return sp_poly_binop_bad("|", a, b);
   /* Integer#| is Integer's alone (see sp_poly_bitop) */
   if (a.tag != SP_TAG_INT && a.tag != SP_TAG_BIGINT) return sp_poly_binop_bad("|", a, b);
+  if (sp_poly_bitop_wide(a, b)) return sp_poly_bitop(a, b, 1);
   return sp_box_int(sp_poly_to_i(a) | sp_poly_bit_operand(b, 0));
 }
 static sp_RbVal sp_poly_bxor(sp_RbVal a, sp_RbVal b) {
@@ -7581,6 +7589,7 @@ static sp_RbVal sp_poly_bxor(sp_RbVal a, sp_RbVal b) {
   if (sp_poly_is_user_obj(a)) return sp_poly_binop_bad("^", a, b);
   /* Integer#^ is Integer's alone (see sp_poly_bitop) */
   if (a.tag != SP_TAG_INT && a.tag != SP_TAG_BIGINT) return sp_poly_binop_bad("^", a, b);
+  if (sp_poly_bitop_wide(a, b)) return sp_poly_bitop(a, b, 2);
   return sp_box_int(sp_poly_to_i(a) ^ sp_poly_bit_operand(b, 0));
 }
 /* Unary minus on a boxed value. Only Float and Integer were handled, and

test/poly_bitop_bignum_width.rb

@@ -0,0 +1,41 @@
+# spinel: int64
+# Integer#&, #| and #^ on a boxed Integer and a Bignum keep the Bignum's
+# width. sp_poly_band, sp_poly_bor and sp_poly_bxor read both sides as
+# int64, so a `|` or `^` line below answered 28 (or 29) where CRuby answers
+# a Bignum. A fold by a Symbol, an element's OP= and a receiver of an
+# unknown kind reach them. A `&` that masks a Bignum fits an int, and stays
+# as it was.
+big = 2**64
+
+pa = [28, big, "x"]
+pa.pop
+p pa.reduce(:|)
+p pa.reduce(:^)
+p [big, 28, :s].first(2).inject(:|)
+p [big + 4, 4, :s].first(2).reduce(:&)
+
+ops = [:|, :+]
+op = ops[ARGV.size]
+p pa.reduce(op)
+
+a = [28, "s"]
+a[0] |= big
+p a[0]
+
+h = {n: 28, s: "t"}
+h[:n] |= big
+p h[:n]
+h[:n] ^= 1
+p h[:n]
+
+r = ARGV.size == 0 ? [28] : {0 => 28}
+r[0] |= big
+p r[0]
+
+# a pair of machine words, and an operand that is not an Integer, as before
+p [28, 3, :s].first(2).reduce(:|)
+begin
+  p [big, 1.5, :s].first(2).reduce(:|)
+rescue TypeError => e
+  p e.message
+end

test/poly_bitop_bignum_width.rb.expected

@@ -0,0 +1,11 @@
+18446744073709551644
+18446744073709551644
+18446744073709551644
+4
+18446744073709551644
+18446744073709551644
+18446744073709551644
+18446744073709551645
+18446744073709551644
+31
+"1.5 can't be coerced into Integer"