rustc_data_structures: Explicitly check for 64-bit atomics support

Instead of keeping a list of architectures which have native support
for 64-bit atomics, just use #[cfg(target_has_atomic = "64")] and its
inverted counterpart to determine whether we need to use portable
AtomicU64 on the target architecture.

1 files changed, 3 insertions, 4 deletions

diff --git a/compiler/rustc_data_structures/src/sync.rs b/compiler/rustc_data_structures/src/sync.rs
index 5ae79ca988f..79ceb28abb5 100644
--- a/compiler/rustc_data_structures/src/sync.rs
+++ b/compiler/rustc_data_structures/src/sync.rs
@@ -270,12 +270,11 @@ cfg_match! {
 
         pub use std::sync::atomic::{AtomicBool, AtomicUsize, AtomicU32};
 
-        // MIPS, PowerPC and SPARC platforms with 32-bit pointers do not
-        // have AtomicU64 type.
-        #[cfg(not(any(target_arch = "mips", target_arch = "powerpc", target_arch = "sparc")))]
+        // Use portable AtomicU64 for targets without native 64-bit atomics
+        #[cfg(target_has_atomic = "64")]
         pub use std::sync::atomic::AtomicU64;
 
-        #[cfg(any(target_arch = "mips", target_arch = "powerpc", target_arch = "sparc"))]
+        #[cfg(not(target_has_atomic = "64"))]
         pub use portable_atomic::AtomicU64;
 
         pub use std::sync::Arc as Lrc;