From 2f2d3b2fd4d38f1ea0c63eb8e880085a2ccf0987 Mon Sep 17 00:00:00 2001
From: bjorn3 <bjorn3@users.noreply.github.com>
Date: Mon, 12 Oct 2020 12:03:18 +0200
Subject: [PATCH] Avoid iadd for ptr const val with zero offset

---
 src/constant.rs | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/constant.rs b/src/constant.rs
index 94ecc3096b38..1b514958a480 100644
--- a/src/constant.rs
+++ b/src/constant.rs
@@ -225,10 +225,13 @@ pub(crate) fn trans_const_value<'tcx>(
                         }
                         None => bug!("missing allocation {:?}", ptr.alloc_id),
                     };
-                    let val = fx
-                        .bcx
-                        .ins()
-                        .iadd_imm(base_addr, i64::try_from(ptr.offset.bytes()).unwrap());
+                    let val = if ptr.offset.bytes() != 0 {
+                        fx.bcx
+                            .ins()
+                            .iadd_imm(base_addr, i64::try_from(ptr.offset.bytes()).unwrap())
+                    } else {
+                        base_addr
+                    };
                     return CValue::by_val(val, layout);
                 }
             }