3 files changed, 6 insertions, 2 deletions
diff --git a/compiler/rustc_codegen_ssa/src/back/command.rs b/compiler/rustc_codegen_ssa/src/back/command.rs
index 05351bd6ca3..7420f18aacb 100644
--- a/compiler/rustc_codegen_ssa/src/back/command.rs
+++ b/compiler/rustc_codegen_ssa/src/back/command.rs
@@ -109,7 +109,7 @@ impl Command {
             }
             Program::Lld(ref p, flavor) => {
                 let mut c = process::Command::new(p);
-                c.arg("-flavor").arg(flavor.as_str());
+                c.arg("-flavor").arg(flavor.desc());
                 c
             }
         };
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 5f6976f5d00..6492ef73956 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -520,7 +520,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 LocalRef::Place(va_list) => {
                     bx.va_end(va_list.val.llval);
 
-                    // Explicitly end the lifetime of the `va_list`, this matters for LLVM.
+                    // Explicitly end the lifetime of the `va_list`, improves LLVM codegen.
                     bx.lifetime_end(va_list.val.llval, va_list.layout.size);
                 }
                 _ => bug!("C-variadic function must have a `VaList` place"),
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index 06873313e2e..6b109e8b8e2 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -438,6 +438,10 @@ fn arg_local_refs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 
             if fx.fn_abi.c_variadic && arg_index == fx.fn_abi.args.len() {
                 let va_list = PlaceRef::alloca(bx, bx.layout_of(arg_ty));
+
+                // Explicitly start the lifetime of the `va_list`, improves LLVM codegen.
+                bx.lifetime_start(va_list.val.llval, va_list.layout.size);
+
                 bx.va_start(va_list.val.llval);
 
                 return LocalRef::Place(va_list);