Cleanup LLVM multi-threading checks

[rust.git] / compiler / rustc_codegen_llvm / src / llvm_util.rs

diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index c5deb11edd094d9776c63685a1c70815e249d162..54767ef683ffe48e8bee4533cee2b914639b2a44 100644 (file)
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -17,35 +17,25 @@
 use std::ptr;
 use std::slice;
 use std::str;
-use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Once;
 
-static POISONED: AtomicBool = AtomicBool::new(false);
 static INIT: Once = Once::new();
 
 pub(crate) fn init(sess: &Session) {
     unsafe {
         // Before we touch LLVM, make sure that multithreading is enabled.
+        if llvm::LLVMIsMultithreaded() != 1 {
+            bug!("LLVM compiled without support for threads");
+        }
         INIT.call_once(|| {
-            if llvm::LLVMStartMultithreaded() != 1 {
-                // use an extra bool to make sure that all future usage of LLVM
-                // cannot proceed despite the Once not running more than once.
-                POISONED.store(true, Ordering::SeqCst);
-            }
-
             configure_llvm(sess);
         });
-
-        if POISONED.load(Ordering::SeqCst) {
-            bug!("couldn't enable multi-threaded LLVM");
-        }
     }
 }
 
 fn require_inited() {
-    INIT.call_once(|| bug!("llvm is not initialized"));
-    if POISONED.load(Ordering::SeqCst) {
-        bug!("couldn't enable multi-threaded LLVM");
+    if !INIT.is_completed() {
+        bug!("LLVM is not initialized");
     }
 }
 
@@ -416,6 +406,11 @@ pub fn llvm_global_features(sess: &Session) -> Vec<String> {
     // -Ctarget-features
     features.extend(sess.opts.cg.target_feature.split(',').flat_map(&filter));
 
+    // FIXME: Move outline-atomics to target definition when earliest supported LLVM is 12.
+    if get_version() >= (12, 0, 0) && sess.target.llvm_target.contains("aarch64-unknown-linux") {
+        features.push("+outline-atomics".to_string());
+    }
+
     features
 }