From 9cf04b5a22e20fd0a537196a610b0e2b85b8d485 Mon Sep 17 00:00:00 2001
From: tiif <pekyuan@gmail.com>
Date: Sat, 8 Jun 2024 00:56:48 +0800
Subject: [PATCH] Use modulo operation to convert nanosecond to Duration

---
 src/tools/miri/src/clock.rs | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/tools/miri/src/clock.rs b/src/tools/miri/src/clock.rs
index da2c54745a03..942593530c37 100644
--- a/src/tools/miri/src/clock.rs
+++ b/src/tools/miri/src/clock.rs
@@ -39,13 +39,14 @@ impl Instant {
                 InstantKind::Virtual { nanoseconds },
                 InstantKind::Virtual { nanoseconds: earlier },
             ) => {
-                // If it exceeded u64::MAX nanosecond, we will just keep u64::MAX nanosecond,
-                // Duration can't take in more than u64::MAX.
-                let duration = match u64::try_from(nanoseconds.saturating_sub(earlier)) {
-                    Ok(nanosecond) => Duration::from_nanos(nanosecond),
-                    Err(_err) => Duration::from_nanos(u64::MAX),
-                };
-                Duration::new(duration.as_secs(), duration.subsec_nanos())
+                // It is possible for second to overflow because u64::MAX < (u128::MAX / 1e9).
+                let seconds = u64::try_from(
+                    nanoseconds.saturating_sub(earlier).saturating_div(1_000_000_000),
+                )
+                .unwrap();
+                // It is impossible for nanosecond to overflow because u32::MAX > 1e9.
+                let nanosecond = u32::try_from(nanoseconds.wrapping_rem(1_000_000_000)).unwrap();
+                Duration::new(seconds, nanosecond)
             }
             _ => panic!("all `Instant` must be of the same kind"),
         }