From 14989dc2c2d75acf0c09a38ffea2d099cb095876 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 5 Sep 2026 20:11:57 +0200
Subject: [PATCH] add regression test for packus_epi16 issue

---
 tests/assembly-llvm/x86-vendor-intrinsics.rs | 21 ++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 tests/assembly-llvm/x86-vendor-intrinsics.rs

diff --git a/tests/assembly-llvm/x86-vendor-intrinsics.rs b/tests/assembly-llvm/x86-vendor-intrinsics.rs
new file mode 100644
index 0000000000000..b600b74c66ecd
--- /dev/null
+++ b/tests/assembly-llvm/x86-vendor-intrinsics.rs
@@ -0,0 +1,21 @@
+// Output differs depending on ABI so we need to match the full target.
+//@ only-x86_64-unknown-linux-gnu
+//@ assembly-output: emit-asm
+//@ compile-flags: -Ctarget-feature=-sse3 -C opt-level=3
+
+// Regression test for various cases where we used to compile x86 vendor intrinsics in a suboptimal
+// way.
+
+#![crate_type = "lib"]
+
+use std::arch::x86_64::*;
+
+// CHECK-LABEL: test_packus_epi16:
+#[unsafe(no_mangle)]
+#[target_feature(enable = "sse2")]
+extern "C" fn test_packus_epi16(a: __m128i, b: __m128i) -> __m128i {
+    // CHECK: .cfi_startproc
+    // CHECK-NEXT: packuswb
+    // CHECK-NEXT: ret
+    _mm_packus_epi16(a, b)
+}