1 files changed, 3 insertions, 2 deletions
diff --git a/src/s2d.rs b/src/s2d.rs
index 3d3808d..152ca97 100644
--- a/src/s2d.rs
+++ b/src/s2d.rs
@@ -203,12 +203,13 @@ pub fn s2d(buffer: &[u8]) -> Result<f64, Error> {
     let round_up = last_removed_bit != 0 && (!trailing_zeros || ((m2 >> shift) & 1) != 0);
 
     let mut ieee_m2 = (m2 >> shift).wrapping_add(round_up as u64);
-    if ieee_m2 == (1_u64 << (d2s::DOUBLE_MANTISSA_BITS + 1)) {
+    debug_assert!(ieee_m2 <= 1_u64 << (d2s::DOUBLE_MANTISSA_BITS + 1));
+    ieee_m2 &= (1_u64 << d2s::DOUBLE_MANTISSA_BITS) - 1;
+    if ieee_m2 == 0 && round_up {
         // Due to how the IEEE represents +/-Infinity, we don't need to check
         // for overflow here.
         ieee_e2 += 1;
     }
-    ieee_m2 &= (1_u64 << d2s::DOUBLE_MANTISSA_BITS) - 1;
     let ieee = ((((signed_m as u64) << d2s::DOUBLE_EXPONENT_BITS) | ieee_e2 as u64)
         << d2s::DOUBLE_MANTISSA_BITS)
         | ieee_m2;