Issue 15535. Normalize remainder in math.big.int.Managed.divTrunc

This commit is contained in:
Brett Hill 2023-05-05 16:02:22 +10:00 committed by Veikka Tuominen
parent 0972196f4d
commit 37f56a4259
2 changed files with 14 additions and 1 deletions

View File

@ -1519,7 +1519,7 @@ pub const Mutable = struct {
r.positive = r_positive;
}
if (xy_trailing != 0) {
if (xy_trailing != 0 and r.limbs[r.len - 1] != 0) {
// Manually shift here since we know its limb aligned.
mem.copyBackwards(Limb, r.limbs[xy_trailing..], r.limbs[0..r.len]);
@memset(r.limbs[0..xy_trailing], 0);

View File

@ -1373,6 +1373,19 @@ test "big.int div trunc single-single -/-" {
try testing.expect((try r.to(i32)) == er);
}
test "big.int divTrunc #15535" {
var one = try Managed.initSet(testing.allocator, 1);
defer one.deinit();
var x = try Managed.initSet(testing.allocator, std.math.pow(u128, 2, 64));
defer x.deinit();
var r = try Managed.init(testing.allocator);
defer r.deinit();
var q = try Managed.init(testing.allocator);
defer q.deinit();
try q.divTrunc(&r, &x, &x);
try testing.expect(r.order(one) == std.math.Order.lt);
}
test "big.int divFloor #10932" {
var a = try Managed.init(testing.allocator);
defer a.deinit();