6 files changed, 57 insertions, 25 deletions
diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs
index dca9c1f04d3..bedd3523d89 100644
--- a/compiler/rustc_codegen_llvm/src/abi.rs
+++ b/compiler/rustc_codegen_llvm/src/abi.rs
@@ -1,7 +1,6 @@
 use crate::builder::Builder;
 use crate::context::CodegenCx;
 use crate::llvm::{self, AttributePlace};
-use crate::llvm_util;
 use crate::type_::Type;
 use crate::type_of::LayoutLlvmExt;
 use crate::value::Value;
@@ -53,15 +52,10 @@ pub trait ArgAttributesExt {
 }
 
 fn should_use_mutable_noalias(cx: &CodegenCx<'_, '_>) -> bool {
-    // LLVM prior to version 12 has known miscompiles in the presence of
-    // noalias attributes (see #54878). Only enable mutable noalias by
-    // default for versions we believe to be safe.
-    cx.tcx
-        .sess
-        .opts
-        .debugging_opts
-        .mutable_noalias
-        .unwrap_or_else(|| llvm_util::get_version() >= (12, 0, 0))
+    // LLVM prior to version 12 had known miscompiles in the presence of
+    // noalias attributes (see #54878), but we don't support earlier
+    // versions at all anymore. We now enable mutable noalias by default.
+    cx.tcx.sess.opts.debugging_opts.mutable_noalias.unwrap_or(true)
 }
 
 impl ArgAttributesExt for ArgAttributes {
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 0707faf610c..6c74163fb49 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -731,7 +731,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     }
 
     fn fptoui_sat(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> Option<&'ll Value> {
-        if llvm_util::get_version() >= (12, 0, 0) && !self.fptoint_sat_broken_in_llvm() {
+        if !self.fptoint_sat_broken_in_llvm() {
             let src_ty = self.cx.val_ty(val);
             let float_width = self.cx.float_width(src_ty);
             let int_width = self.cx.int_width(dest_ty);
@@ -743,7 +743,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     }
 
     fn fptosi_sat(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> Option<&'ll Value> {
-        if llvm_util::get_version() >= (12, 0, 0) && !self.fptoint_sat_broken_in_llvm() {
+        if !self.fptoint_sat_broken_in_llvm() {
             let src_ty = self.cx.val_ty(val);
             let float_width = self.cx.float_width(src_ty);
             let int_width = self.cx.int_width(dest_ty);
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index cda766039c1..1dba264a961 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -134,9 +134,6 @@ pub unsafe fn create_module(
     let llmod = llvm::LLVMModuleCreateWithNameInContext(mod_name.as_ptr(), llcx);
 
     let mut target_data_layout = sess.target.data_layout.clone();
-    if llvm_util::get_version() < (12, 0, 0) && sess.target.arch == "powerpc64" {
-        target_data_layout = target_data_layout.replace("-v256:256:256-v512:512:512", "");
-    }
     if llvm_util::get_version() < (13, 0, 0) {
         if sess.target.arch == "powerpc64" {
             target_data_layout = target_data_layout.replace("-S128", "");
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 8f4d79e7147..64fedb7bc1a 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -76,6 +76,27 @@ mod value;
 #[derive(Clone)]
 pub struct LlvmCodegenBackend(());
 
+struct TimeTraceProfiler {
+    enabled: bool,
+}
+
+impl TimeTraceProfiler {
+    fn new(enabled: bool) -> Self {
+        if enabled {
+            unsafe { llvm::LLVMTimeTraceProfilerInitialize() }
+        }
+        TimeTraceProfiler { enabled }
+    }
+}
+
+impl Drop for TimeTraceProfiler {
+    fn drop(&mut self) {
+        if self.enabled {
+            unsafe { llvm::LLVMTimeTraceProfilerFinishThread() }
+        }
+    }
+}
+
 impl ExtraBackendMethods for LlvmCodegenBackend {
     fn new_metadata(&self, tcx: TyCtxt<'_>, mod_name: &str) -> ModuleLlvm {
         ModuleLlvm::new_metadata(tcx, mod_name)
@@ -119,6 +140,34 @@ impl ExtraBackendMethods for LlvmCodegenBackend {
     fn tune_cpu<'b>(&self, sess: &'b Session) -> Option<&'b str> {
         llvm_util::tune_cpu(sess)
     }
+
+    fn spawn_thread<F, T>(time_trace: bool, f: F) -> std::thread::JoinHandle<T>
+    where
+        F: FnOnce() -> T,
+        F: Send + 'static,
+        T: Send + 'static,
+    {
+        std::thread::spawn(move || {
+            let _profiler = TimeTraceProfiler::new(time_trace);
+            f()
+        })
+    }
+
+    fn spawn_named_thread<F, T>(
+        time_trace: bool,
+        name: String,
+        f: F,
+    ) -> std::io::Result<std::thread::JoinHandle<T>>
+    where
+        F: FnOnce() -> T,
+        F: Send + 'static,
+        T: Send + 'static,
+    {
+        std::thread::Builder::new().name(name).spawn(move || {
+            let _profiler = TimeTraceProfiler::new(time_trace);
+            f()
+        })
+    }
 }
 
 impl WriteBackendMethods for LlvmCodegenBackend {
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index 21d2388fc30..749eec459ac 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -1737,6 +1737,8 @@ extern "C" {
 
     pub fn LLVMTimeTraceProfilerInitialize();
 
+    pub fn LLVMTimeTraceProfilerFinishThread();
+
     pub fn LLVMTimeTraceProfilerFinish(FileName: *const c_char);
 
     pub fn LLVMAddAnalysisPasses(T: &'a TargetMachine, PM: &PassManager<'a>);
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 246bb88885d..c3e7e7169a9 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -113,11 +113,6 @@ unsafe fn configure_llvm(sess: &Session) {
     }
 
     if sess.opts.debugging_opts.llvm_time_trace {
-        // time-trace is not thread safe and running it in parallel will cause seg faults.
-        if !sess.opts.debugging_opts.no_parallel_llvm {
-            bug!("`-Z llvm-time-trace` requires `-Z no-parallel-llvm")
-        }
-
         llvm::LLVMTimeTraceProfilerInitialize();
     }
 
@@ -406,11 +401,6 @@ 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
 }