From f0fda53cc107ccb581a2493e9f02200413e6055d Mon Sep 17 00:00:00 2001
From: Danek Duvall <danek.duvall@oracle.com>
Date: Tue, 25 Jul 2017 14:32:08 -0700
Subject: [PATCH] Constrain the layout of Blake2bCtx for proper SPARC
 compilation

On SPARC, optimization fuel ends up emitting incorrect load and store
instructions for the transmute() call in blake2b_compress().  If we
force Blake2bCtx to be repr(C), the problem disappears.

Fixes #43346
---
 src/librustc_data_structures/blake2b.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/librustc_data_structures/blake2b.rs b/src/librustc_data_structures/blake2b.rs
index bdef9fefd41e4..5adeef1ab3a6d 100644
--- a/src/librustc_data_structures/blake2b.rs
+++ b/src/librustc_data_structures/blake2b.rs
@@ -23,6 +23,7 @@
 use std::mem;
 use std::slice;
 
+#[repr(C)]
 pub struct Blake2bCtx {
     b: [u8; 128],
     h: [u64; 8],