From 02a141a5506ae499367c67e147688d049dd96efb Mon Sep 17 00:00:00 2001
From: Eduard Burtescu <edy.burt@gmail.com>
Date: Thu, 10 Mar 2016 21:47:25 +0200
Subject: [PATCH] mir: Don't memset allocas of types that do not require drop.

---
 src/librustc_trans/trans/mir/lvalue.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/librustc_trans/trans/mir/lvalue.rs b/src/librustc_trans/trans/mir/lvalue.rs
index a8c67549380..ffc3b120674 100644
--- a/src/librustc_trans/trans/mir/lvalue.rs
+++ b/src/librustc_trans/trans/mir/lvalue.rs
@@ -51,7 +51,9 @@ impl<'tcx> LvalueRef<'tcx> {
     {
         assert!(!ty.has_erasable_regions());
         let lltemp = bcx.with_block(|bcx| base::alloc_ty(bcx, ty, name));
-        drop::drop_fill(bcx, lltemp, ty);
+        if bcx.fcx().type_needs_drop(ty) {
+            drop::drop_fill(bcx, lltemp, ty);
+        }
         LvalueRef::new_sized(lltemp, LvalueTy::from_ty(ty))
     }
 }