From cfa76c438a907bf223e4487ab4da2500277474cc Mon Sep 17 00:00:00 2001
From: gnzlbg <gonzalobg88@gmail.com>
Date: Mon, 25 Mar 2019 11:49:08 +0100
Subject: [PATCH] black_box should inhibit optimizations on platforms without
 inline assembly

---
 src/libcore/hint.rs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/libcore/hint.rs b/src/libcore/hint.rs
index 75d64bbe0fb..abaf0b31b46 100644
--- a/src/libcore/hint.rs
+++ b/src/libcore/hint.rs
@@ -106,7 +106,10 @@ pub fn black_box<T>(dummy: T) -> T {
         dummy
     }
     #[cfg(any(target_arch = "asmjs", target_arch = "wasm32"))] {
-        #[inline(never)] fn black_box_(x: T) -> T { x }
-        black_box_(dummy)
-    }
+        unsafe {
+            let ret = crate::ptr::read_volatile(&dummy);
+            crate::mem::forget(dummy);
+            ret
+        }
+   }
 }