Fix problems with logxor etc. and fixnums

These operations incorrectly treated negative fixnums as
bignums greater than most-positive-fixnum.
* src/alloc.c (mpz_set_intmax_slow): Avoid undefined
behavior if signed unary negation overflows, while
we’re in the neighborhood.
(mpz_set_uintmax_slow): Remove.  All uses removed.
* src/data.c (arith_driver): Treat fixnums as signed, not
unsigned, even for logical operations.
* src/lisp.h (mpz_set_uintmax): Remove.  All uses removed.
* test/src/data-tests.el (data-tests-logand)
(data-tests-logior, data-tests-logxor): New tests.

1 files changed, 14 insertions, 0 deletions

diff --git a/test/src/data-tests.el b/test/src/data-tests.el
index 82649022576..a4c6b0e4915 100644
--- a/test/src/data-tests.el
+++ b/test/src/data-tests.el
@@ -597,9 +597,23 @@ comparing the subr with a much slower lisp implementation."
   (should (< (1- most-negative-fixnum) most-negative-fixnum))
   (should (fixnump (1- (1+ most-positive-fixnum)))))
 
+(ert-deftest data-tests-logand ()
+  (should (= -1 (logand -1)))
+  (let ((n (* 2 most-negative-fixnum)))
+    (should (= (logand -1 n) n))))
+
 (ert-deftest data-tests-logcount ()
   (should (= (logcount (read "#xffffffffffffffffffffffffffffffff")) 128)))
 
+(ert-deftest data-tests-logior ()
+  (should (= -1 (logior -1)))
+  (should (= -1 (logior most-positive-fixnum most-negative-fixnum))))
+
+(ert-deftest data-tests-logxor ()
+  (should (= -1 (logxor -1)))
+  (let ((n (1+ most-positive-fixnum)))
+    (should (= (logxor -1 n) (lognot n)))))
+
 (ert-deftest data-tests-minmax ()
   (let ((a (- most-negative-fixnum 1))
         (b (+ most-positive-fixnum 1))