py/mpz: Do Python style division/modulo within bignum divmod routine.

This patch consolidates the Python logic for division/modulo to one place
within the bignum code.

py/mpz.c

@@ -1509,8 +1509,14 @@ void mpz_divmod_inpl(mpz_t *dest_quo, mpz_t *dest_rem, const mpz_t *lhs, const m
     //rhs->dig[rhs->len] = 0;
     mpn_div(dest_rem->dig, &dest_rem->len, rhs->dig, rhs->len, dest_quo->dig, &dest_quo->len);
 
+    // check signs and do Python style modulo
     if (lhs->neg != rhs->neg) {
         dest_quo->neg = 1;
+        if (!mpz_is_zero(dest_rem)) {
+            mpz_t mpzone; mpz_init_from_int(&mpzone, -1);
+            mpz_add_inpl(dest_quo, dest_quo, &mpzone);
+            mpz_add_inpl(dest_rem, dest_rem, rhs);
+        }
     }
 }
 

py/objint_mpz.c

@@ -239,12 +239,6 @@ mp_obj_t mp_obj_int_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
                 }
                 mpz_t rem; mpz_init_zero(&rem);
                 mpz_divmod_inpl(&res->mpz, &rem, zlhs, zrhs);
-                if (zlhs->neg != zrhs->neg) {
-                    if (!mpz_is_zero(&rem)) {
-                        mpz_t mpzone; mpz_init_from_int(&mpzone, -1);
-                        mpz_add_inpl(&res->mpz, &res->mpz, &mpzone);
-                    }
-                }
                 mpz_deinit(&rem);
                 break;
             }
@@ -256,10 +250,6 @@ mp_obj_t mp_obj_int_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
                 mpz_t quo; mpz_init_zero(&quo);
                 mpz_divmod_inpl(&quo, &res->mpz, zlhs, zrhs);
                 mpz_deinit(&quo);
-                // Check signs and do Python style modulo
-                if (zlhs->neg != zrhs->neg) {
-                    mpz_add_inpl(&res->mpz, &res->mpz, zrhs);
-                }
                 break;
             }
 
@@ -303,10 +293,6 @@ mp_obj_t mp_obj_int_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
                 }
                 mp_obj_int_t *quo = mp_obj_int_new_mpz();
                 mpz_divmod_inpl(&quo->mpz, &res->mpz, zlhs, zrhs);
-                // Check signs and do Python style modulo
-                if (zlhs->neg != zrhs->neg) {
-                    mpz_add_inpl(&res->mpz, &res->mpz, zrhs);
-                }
                 mp_obj_t tuple[2] = {MP_OBJ_FROM_PTR(quo), MP_OBJ_FROM_PTR(res)};
                 return mp_obj_new_tuple(2, tuple);
             }

tests/basics/int_big_mod.py

@@ -4,8 +4,8 @@ delta = 100000000000000000000000000000012345
 
 for i in range(11):
     for j in range(11):
-        x = delta * (i)# - 5) # TODO reinstate negative number test when % is working with sign correctly
-        y = delta * (j)# - 5) # TODO reinstate negative number test when % is working with sign correctly
+        x = delta * (i - 5)
+        y = delta * (j - 5)
         if y != 0:
             print(x % y)