1 > -1

src/operator.rs

@@ -235,9 +235,13 @@ pub fn binary_op<'tcx>(
 
         (Eq, _) => PrimVal::from_bool(l == r),
         (Ne, _) => PrimVal::from_bool(l != r),
+        (Lt, k) if k.is_signed_int() => PrimVal::from_bool((l as i128) < (r as i128)),
         (Lt, _) => PrimVal::from_bool(l <  r),
+        (Le, k) if k.is_signed_int() => PrimVal::from_bool((l as i128) <= (r as i128)),
         (Le, _) => PrimVal::from_bool(l <= r),
+        (Gt, k) if k.is_signed_int() => PrimVal::from_bool((l as i128) > (r as i128)),
         (Gt, _) => PrimVal::from_bool(l >  r),
+        (Ge, k) if k.is_signed_int() => PrimVal::from_bool((l as i128) >= (r as i128)),
         (Ge, _) => PrimVal::from_bool(l >= r),
 
         (BitOr,  _) => PrimVal::Bytes(l | r),

src/value.rs

@@ -214,6 +214,14 @@ impl PrimValKind {
         }
     }
 
+    pub fn is_signed_int(self) -> bool {
+        use self::PrimValKind::*;
+        match self {
+            I8 | I16 | I32 | I64 | I128 => true,
+            _ => false,
+        }
+    }
+
     pub fn from_uint_size(size: u64) -> Self {
         match size {
             1 => PrimValKind::U8,

tests/run-pass/issue-15523-big.rs

@@ -0,0 +1,48 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Issue 15523: derive(PartialOrd) should use the provided
+// discriminant values for the derived ordering.
+//
+// This test is checking corner cases that arise when you have
+// 64-bit values in the variants.
+
+#[derive(PartialEq, PartialOrd)]
+#[repr(u64)]
+enum Eu64 {
+    Pos2 = 2,
+    PosMax = !0,
+    Pos1 = 1,
+}
+
+#[derive(PartialEq, PartialOrd)]
+#[repr(i64)]
+enum Ei64 {
+    Pos2 = 2,
+    Neg1 = -1,
+    NegMin = 1 << 63,
+    PosMax = !(1 << 63),
+    Pos1 = 1,
+}
+
+fn main() {
+    assert!(Eu64::Pos2 > Eu64::Pos1);
+    assert!(Eu64::Pos2 < Eu64::PosMax);
+    assert!(Eu64::Pos1 < Eu64::PosMax);
+
+
+    assert!(Ei64::Pos2 > Ei64::Pos1);
+    assert!(Ei64::Pos2 > Ei64::Neg1);
+    assert!(Ei64::Pos1 > Ei64::Neg1);
+    assert!(Ei64::Pos2 > Ei64::NegMin);
+    assert!(Ei64::Pos1 > Ei64::NegMin);
+    assert!(Ei64::Pos2 < Ei64::PosMax);
+    assert!(Ei64::Pos1 < Ei64::PosMax);
+}