changed order of evaluation to avoid underflow (#575)

lambdaclass · Sep 25, 2023 · 8e0438a · 8e0438a
1 parent 0a299a7
commit 8e0438a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/math/src/unsigned_integer/element.rs b/math/src/unsigned_integer/element.rs
@@ -707,7 +707,7 @@ impl<const NUM_LIMBS: usize> UnsignedInteger<NUM_LIMBS> {
         while i > 0 {
             i -= 1;
             if NUM_LIMBS - 1 <= i * 2 {
-                let index = 2 * i - NUM_LIMBS + 1;
+                let index = 2 * i + 1 - NUM_LIMBS;
                 let cs = lo.limbs[index] as u128 + a.limbs[i] as u128 * a.limbs[i] as u128 + c;
                 c = cs >> 64;
                 lo.limbs[index] = cs as u64;