From 964ba2a6e731f79d99248d1f0e67eac17e69e368 Mon Sep 17 00:00:00 2001
From: Robin Kruppe <robin.kruppe@gmail.com>
Date: Sun, 15 Oct 2017 20:10:42 +0200
Subject: [PATCH] Fix bug in rustc_apfloat

---
 src/librustc_apfloat/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/librustc_apfloat/lib.rs b/src/librustc_apfloat/lib.rs
index 9e348f622232..2048127222bb 100644
--- a/src/librustc_apfloat/lib.rs
+++ b/src/librustc_apfloat/lib.rs
@@ -378,7 +378,7 @@ fn copy_sign(self, rhs: Self) -> Self {
     fn from_bits(input: u128) -> Self;
     fn from_i128_r(input: i128, round: Round) -> StatusAnd<Self> {
         if input < 0 {
-            Self::from_u128_r(-input as u128, -round).map(|r| -r)
+            Self::from_u128_r(input.wrapping_neg() as u128, -round).map(|r| -r)
         } else {
             Self::from_u128_r(input as u128, round)
         }