Auto merge of #22860 - Manishearth:rollup, r=alexcrichton

Passes check-stage1, check-stage2

3 files changed, 26 insertions, 17 deletions

diff --git a/src/libstd/sys/unix/fs.rs b/src/libstd/sys/unix/fs.rs
index 1c28d629d40..71b6214460f 100644
--- a/src/libstd/sys/unix/fs.rs
+++ b/src/libstd/sys/unix/fs.rs
@@ -291,29 +291,14 @@ fn mkstat(stat: &libc::stat) -> FileStat {
     // FileStat times are in milliseconds
     fn mktime(secs: u64, nsecs: u64) -> u64 { secs * 1000 + nsecs / 1000000 }
 
-    #[cfg(target_os = "bitrig")]
-    fn ctime(stat: &libc::stat) -> u64 {
-      mktime(stat.st_ctim.tv_sec as u64, stat.st_ctim.tv_nsec as u64)
-    }
-    #[cfg(not(target_os = "bitrig"))]
     fn ctime(stat: &libc::stat) -> u64 {
       mktime(stat.st_ctime as u64, stat.st_ctime_nsec as u64)
     }
 
-    #[cfg(target_os = "bitrig")]
-    fn atime(stat: &libc::stat) -> u64 {
-      mktime(stat.st_atim.tv_sec as u64, stat.st_atim.tv_nsec as u64)
-    }
-    #[cfg(not(target_os = "bitrig"))]
     fn atime(stat: &libc::stat) -> u64 {
       mktime(stat.st_atime as u64, stat.st_atime_nsec as u64)
     }
 
-    #[cfg(target_os = "bitrig")]
-    fn mtime(stat: &libc::stat) -> u64 {
-      mktime(stat.st_mtim.tv_sec as u64, stat.st_mtim.tv_nsec as u64)
-    }
-    #[cfg(not(target_os = "bitrig"))]
     fn mtime(stat: &libc::stat) -> u64 {
       mktime(stat.st_mtime as u64, stat.st_mtime_nsec as u64)
     }
diff --git a/src/libstd/sys/unix/process2.rs b/src/libstd/sys/unix/process2.rs
index b7a1b002f55..a7d0a864a08 100644
--- a/src/libstd/sys/unix/process2.rs
+++ b/src/libstd/sys/unix/process2.rs
@@ -439,6 +439,7 @@ fn translate_status(status: c_int) -> ExitStatus {
               target_os = "ios",
               target_os = "freebsd",
               target_os = "dragonfly",
+              target_os = "bitrig",
               target_os = "openbsd"))]
     mod imp {
         pub fn WIFEXITED(status: i32) -> bool { (status & 0x7f) == 0 }
diff --git a/src/libstd/sys/windows/time.rs b/src/libstd/sys/windows/time.rs
index 20ceff0aa69..209460df10b 100644
--- a/src/libstd/sys/windows/time.rs
+++ b/src/libstd/sys/windows/time.rs
@@ -12,6 +12,8 @@ use ops::Sub;
 use time::Duration;
 use sync::{Once, ONCE_INIT};
 
+const NANOS_PER_SEC: i64 = 1_000_000_000;
+
 pub struct SteadyTime {
     t: libc::LARGE_INTEGER,
 }
@@ -24,7 +26,7 @@ impl SteadyTime {
     }
 
     pub fn ns(&self) -> u64 {
-        self.t as u64 * 1_000_000_000 / frequency() as u64
+        mul_div_i64(self.t as i64, NANOS_PER_SEC, frequency() as i64) as u64
     }
 }
 
@@ -45,6 +47,27 @@ impl<'a> Sub for &'a SteadyTime {
 
     fn sub(self, other: &SteadyTime) -> Duration {
         let diff = self.t as i64 - other.t as i64;
-        Duration::microseconds(diff * 1_000_000 / frequency() as i64)
+        Duration::nanoseconds(mul_div_i64(diff, NANOS_PER_SEC, frequency() as i64))
     }
 }
+
+// Computes (value*numer)/denom without overflow, as long as both
+// (numer*denom) and the overall result fit into i64 (which is the case
+// for our time conversions).
+fn mul_div_i64(value: i64, numer: i64, denom: i64) -> i64 {
+    let q = value / denom;
+    let r = value % denom;
+    // Decompose value as (value/denom*denom + value%denom),
+    // substitute into (value*numer)/denom and simplify.
+    // r < denom, so (denom*numer) is the upper bound of (r*numer)
+    q * numer + r * numer / denom
+}
+
+#[test]
+fn test_muldiv() {
+    assert_eq!(mul_div_i64( 1_000_000_000_001, 1_000_000_000, 1_000_000),  1_000_000_000_001_000);
+    assert_eq!(mul_div_i64(-1_000_000_000_001, 1_000_000_000, 1_000_000), -1_000_000_000_001_000);
+    assert_eq!(mul_div_i64(-1_000_000_000_001,-1_000_000_000, 1_000_000),  1_000_000_000_001_000);
+    assert_eq!(mul_div_i64( 1_000_000_000_001, 1_000_000_000,-1_000_000), -1_000_000_000_001_000);
+    assert_eq!(mul_div_i64( 1_000_000_000_001,-1_000_000_000,-1_000_000),  1_000_000_000_001_000);
+}