diff --git a/compiler/rustc_codegen_llvm/src/va_arg.rs b/compiler/rustc_codegen_llvm/src/va_arg.rs
index 7eb5d30205887..ab08125217ff5 100644
--- a/compiler/rustc_codegen_llvm/src/va_arg.rs
+++ b/compiler/rustc_codegen_llvm/src/va_arg.rs
@@ -908,6 +908,21 @@ pub(super) fn emit_va_arg<'ll, 'tcx>(
             )
         }
         "aarch64" => emit_aapcs_va_arg(bx, addr, target_ty),
+        "arm" => {
+            // Types wider than 16 bytes are not currently supported. Clang has special logic for
+            // such types, but `VaArgSafe` is not implemented for any type that is this large.
+            assert!(bx.cx.size_of(target_ty).bytes() <= 16);
+
+            emit_ptr_va_arg(
+                bx,
+                addr,
+                target_ty,
+                PassMode::Direct,
+                SlotSize::Bytes4,
+                AllowHigherAlign::Yes,
+                ForceRightAdjust::No,
+            )
+        }
         "s390x" => emit_s390x_va_arg(bx, addr, target_ty),
         "powerpc" => emit_powerpc_va_arg(bx, addr, target_ty),
         "powerpc64" | "powerpc64le" => emit_ptr_va_arg(
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 5f6976f5d0051..6492ef73956b0 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 06873313e2ecd..6b109e8b8e2f4 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);
diff --git a/tests/assembly-llvm/c-variadic-arm.rs b/tests/assembly-llvm/c-variadic-arm.rs
new file mode 100644
index 0000000000000..2ef307405e131
--- /dev/null
+++ b/tests/assembly-llvm/c-variadic-arm.rs
@@ -0,0 +1,26 @@
+//@ assembly-output: emit-asm
+//@ compile-flags: -Copt-level=3
+//@ only-arm
+//@ ignore-thumb
+//@ ignore-android
+#![no_std]
+#![crate_type = "lib"]
+#![feature(c_variadic)]
+
+// Check that the assembly that rustc generates matches what clang emits.
+
+#[unsafe(no_mangle)]
+unsafe extern "C" fn variadic(a: f64, mut args: ...) -> f64 {
+    // CHECK-LABEL: variadic
+    // CHECK: sub sp, sp
+
+    // CHECK: vldr
+    // CHECK: vadd.f64
+    // CHECK: vldr
+    // CHECK: vadd.f64
+    let b = args.arg::<f64>();
+    let c = args.arg::<f64>();
+    a + b + c
+
+    // CHECK: add sp, sp
+}
diff --git a/tests/codegen-llvm/c-variadic-lifetime.rs b/tests/codegen-llvm/c-variadic-lifetime.rs
new file mode 100644
index 0000000000000..5b2f8af18c817
--- /dev/null
+++ b/tests/codegen-llvm/c-variadic-lifetime.rs
@@ -0,0 +1,21 @@
+//@ add-core-stubs
+//@ compile-flags: -Copt-level=3
+#![feature(c_variadic)]
+#![crate_type = "lib"]
+
+// Check that `%args` explicitly has its lifetime start and end. Being explicit can improve
+// instruction and register selection, see e.g. https://github.com/rust-lang/rust/pull/144549
+
+#[unsafe(no_mangle)]
+unsafe extern "C" fn variadic(a: f64, mut args: ...) -> f64 {
+    // CHECK: call void @llvm.lifetime.start.p0(i64 {{[0-9]+}}, ptr nonnull %args)
+    // CHECK: call void @llvm.va_start.p0(ptr nonnull %args)
+
+    let b = args.arg::<f64>();
+    let c = args.arg::<f64>();
+
+    a + b + c
+
+    // CHECK: call void @llvm.va_end.p0(ptr nonnull %args)
+    // CHECK: call void @llvm.lifetime.end.p0(i64 {{[0-9]+}}, ptr nonnull %args)
+}