Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Compute gcd with u64 instead of i64 because of overflows #11036

Merged
merged 4 commits into from
Jun 21, 2024
Merged

Compute gcd with u64 instead of i64 because of overflows #11036

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
c251260
compute gcd with unsigned ints
LorrensP-2158466 Jun 20, 2024
129ba75
add test for the i64::MAX cases
LorrensP-2158466 Jun 20, 2024
2486608
move unsigned_abs below zero test to remove unnecessary casts
LorrensP-2158466 Jun 21, 2024
0700581
add slt test for gcd on max values instead of unit tests
LorrensP-2158466 Jun 21, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 9 additions & 8 deletions datafusion/functions/src/math/gcd.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -88,16 +88,16 @@ fn gcd(args: &[ArrayRef]) -> Result<ArrayRef> {

/// Computes greatest common divisor using Binary GCD algorithm.
pub fn compute_gcd(x: i64, y: i64) -> i64 {
let mut a = x.wrapping_abs();
let mut b = y.wrapping_abs();

if a == 0 {
return b;
if x == 0 {
return y;
}
if b == 0 {
return a;
if y == 0 {
return x;
}

let mut a = x.unsigned_abs();
let mut b = y.unsigned_abs();

let shift = (a | b).trailing_zeros();
a >>= shift;
b >>= shift;
Expand All @@ -112,7 +112,8 @@ pub fn compute_gcd(x: i64, y: i64) -> i64 {
b -= a;

if b == 0 {
return a << shift;
// because the input values are i64, casting this back to i64 is safe
return (a << shift) as i64;
}
}
}
Expand Down
10 changes: 10 additions & 0 deletions datafusion/sqllogictest/test_files/scalar.slt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -474,6 +474,16 @@ select gcd(null, null);
----
NULL

# scalar maxes and/or negative 1
query III rowsort
select
gcd(9223372036854775807, -9223372036854775808), -- i64::MIN, i64::MAX
-- wait till fix, cause it fails gcd(-9223372036854775808, -9223372036854775808), -- -i64::MIN, i64::MIN
gcd(9223372036854775807, -1), -- i64::MAX, -1
gcd(-9223372036854775808, -1); -- i64::MIN, -1
----
1 1 1

# gcd with columns
query III rowsort
select gcd(a, b), gcd(c, d), gcd(e, f) from signed_integers;
Expand Down