Auto merge of #30969 - Amanieu:extended_atomic_cmpxchg, r=alexcrichton

This is an implementation of rust-lang/rfcs#1443.

2 files changed, 68 insertions, 0 deletions

diff --git a/src/test/run-pass/atomic-compare_exchange.rs b/src/test/run-pass/atomic-compare_exchange.rs
new file mode 100644
index 00000000000..7946704709c
--- /dev/null
+++ b/src/test/run-pass/atomic-compare_exchange.rs
@@ -0,0 +1,37 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(extended_compare_and_swap)]
+use std::sync::atomic::{AtomicIsize, ATOMIC_ISIZE_INIT};
+use std::sync::atomic::Ordering::*;
+
+static ATOMIC: AtomicIsize = ATOMIC_ISIZE_INIT;
+
+fn main() {
+    // Make sure trans can emit all the intrinsics correctly
+    ATOMIC.compare_exchange(0, 1, Relaxed, Relaxed);
+    ATOMIC.compare_exchange(0, 1, Acquire, Relaxed);
+    ATOMIC.compare_exchange(0, 1, Release, Relaxed);
+    ATOMIC.compare_exchange(0, 1, AcqRel, Relaxed);
+    ATOMIC.compare_exchange(0, 1, SeqCst, Relaxed);
+    ATOMIC.compare_exchange(0, 1, Acquire, Acquire);
+    ATOMIC.compare_exchange(0, 1, AcqRel, Acquire);
+    ATOMIC.compare_exchange(0, 1, SeqCst, Acquire);
+    ATOMIC.compare_exchange(0, 1, SeqCst, SeqCst);
+    ATOMIC.compare_exchange_weak(0, 1, Relaxed, Relaxed);
+    ATOMIC.compare_exchange_weak(0, 1, Acquire, Relaxed);
+    ATOMIC.compare_exchange_weak(0, 1, Release, Relaxed);
+    ATOMIC.compare_exchange_weak(0, 1, AcqRel, Relaxed);
+    ATOMIC.compare_exchange_weak(0, 1, SeqCst, Relaxed);
+    ATOMIC.compare_exchange_weak(0, 1, Acquire, Acquire);
+    ATOMIC.compare_exchange_weak(0, 1, AcqRel, Acquire);
+    ATOMIC.compare_exchange_weak(0, 1, SeqCst, Acquire);
+    ATOMIC.compare_exchange_weak(0, 1, SeqCst, SeqCst);
+}
diff --git a/src/test/run-pass/intrinsic-atomics.rs b/src/test/run-pass/intrinsic-atomics.rs
index 4ccab55e943..3cc125e9513 100644
--- a/src/test/run-pass/intrinsic-atomics.rs
+++ b/src/test/run-pass/intrinsic-atomics.rs
@@ -19,6 +19,10 @@ mod rusti {
         pub fn atomic_cxchg_acq<T>(dst: *mut T, old: T, src: T) -> T;
         pub fn atomic_cxchg_rel<T>(dst: *mut T, old: T, src: T) -> T;
 
+        pub fn atomic_cxchgweak<T>(dst: *mut T, old: T, src: T) -> (T, bool);
+        pub fn atomic_cxchgweak_acq<T>(dst: *mut T, old: T, src: T) -> (T, bool);
+        pub fn atomic_cxchgweak_rel<T>(dst: *mut T, old: T, src: T) -> (T, bool);
+
         pub fn atomic_load<T>(src: *const T) -> T;
         pub fn atomic_load_acq<T>(src: *const T) -> T;
 
@@ -79,5 +83,32 @@ pub fn main() {
         assert_eq!(rusti::atomic_xsub_acq(&mut *x, 1), 2);
         assert_eq!(rusti::atomic_xsub_rel(&mut *x, 1), 1);
         assert_eq!(*x, 0);
+
+        loop {
+            let res = rusti::atomic_cxchgweak(&mut *x, 0, 1);
+            assert_eq!(res.0, 0);
+            if res.1 {
+                break;
+            }
+        }
+        assert_eq!(*x, 1);
+
+        loop {
+            let res = rusti::atomic_cxchgweak_acq(&mut *x, 1, 2);
+            assert_eq!(res.0, 1);
+            if res.1 {
+                break;
+            }
+        }
+        assert_eq!(*x, 2);
+
+        loop {
+            let res = rusti::atomic_cxchgweak_rel(&mut *x, 2, 3);
+            assert_eq!(res.0, 2);
+            if res.1 {
+                break;
+            }
+        }
+        assert_eq!(*x, 3);
     }
 }