From 0b3dba8e702fa7f4a0135098dfe77c98db45490a Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Tue, 16 Feb 2021 09:51:53 +0100
Subject: [PATCH 1/2] rustup and temporarily disable broken tests

---
 rust-version                                        | 2 +-
 tests/compile-fail/validity/execute_memory.rs       | 1 +
 tests/compile-fail/validity/invalid_fnptr_uninit.rs | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/rust-version b/rust-version
index 26199e0b483..0c82a59c6d1 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-bb587b1a1737738658d2eaecd4c8c1cab555257a
+42a4673fbd40b09a99d057eaa9b3e5579b54c184
diff --git a/tests/compile-fail/validity/execute_memory.rs b/tests/compile-fail/validity/execute_memory.rs
index 5230e7fdf52..4be80fe39d0 100644
--- a/tests/compile-fail/validity/execute_memory.rs
+++ b/tests/compile-fail/validity/execute_memory.rs
@@ -1,3 +1,4 @@
+// ignore-test FIXME (Miri issue #1711)
 #![feature(box_syntax)]
 
 fn main() {
diff --git a/tests/compile-fail/validity/invalid_fnptr_uninit.rs b/tests/compile-fail/validity/invalid_fnptr_uninit.rs
index dbd6711dc65..ab0e870b420 100644
--- a/tests/compile-fail/validity/invalid_fnptr_uninit.rs
+++ b/tests/compile-fail/validity/invalid_fnptr_uninit.rs
@@ -1,3 +1,4 @@
+// ignore-test FIXME (Miri issue #1711)
 #![allow(invalid_value)]
 
 union MyUninit {

From 4c867feeb637e0172f4c72a3732f9beb5e4f922d Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Tue, 16 Feb 2021 09:55:44 +0100
Subject: [PATCH 2/2] add test by @eddyb

---
 .../branchless-select-i128-pointer.rs         | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 tests/compile-fail/branchless-select-i128-pointer.rs

diff --git a/tests/compile-fail/branchless-select-i128-pointer.rs b/tests/compile-fail/branchless-select-i128-pointer.rs
new file mode 100644
index 00000000000..61fd57f8f05
--- /dev/null
+++ b/tests/compile-fail/branchless-select-i128-pointer.rs
@@ -0,0 +1,20 @@
+use std::mem::transmute;
+
+#[cfg(target_pointer_width = "32")]
+type TwoPtrs = i64;
+#[cfg(target_pointer_width = "64")]
+type TwoPtrs = i128;
+
+fn main() {
+    for &my_bool in &[true, false] {
+        let mask = -(my_bool as TwoPtrs); // false -> 0, true -> -1 aka !0
+        // This is branchless code to select one or the other pointer.
+        // For now, Miri brafs on it, but if this code ever passes we better make sure it behaves correctly.
+        let val = unsafe {
+            transmute::<_, &str>(
+                !mask & transmute::<_, TwoPtrs>("false !") | mask & transmute::<_, TwoPtrs>("true !"), //~ERROR encountered (potentially part of) a pointer, but expected plain (non-pointer) bytes
+            )
+        };
+        println!("{}", val);
+    }
+}