regression test for intrinsics may not inline properly on pclmulqdq

Author: lucarlig

tests/codegen-llvm/pclmulqdq-target-feature-inlining.rs

@@ -0,0 +1,34 @@
+// Test for pclmulqdq intrinsics inlining across target_feature boundaries
+// Issue: https://github.com/rust-lang/rust/issues/139029
+//
+// When a function with target_feature calls another function without matching
+// target_feature attributes, the intrinsics may not inline properly, leading
+// to function calls instead of direct instructions.
+
+//@ only-x86_64
+//@ compile-flags: -C opt-level=3
+
+#![crate_type = "lib"]
+
+use std::arch::x86_64 as arch;
+
+// CHECK-LABEL: @reduce128_caller
+// CHECK-NOT: call
+// CHECK: call <2 x i64> @llvm.x86.pclmulqdq
+// CHECK: call <2 x i64> @llvm.x86.pclmulqdq
+// CHECK-NOT: call
+#[target_feature(enable = "pclmulqdq", enable = "sse2", enable = "sse4.1")]
+#[no_mangle]
+pub unsafe fn reduce128_caller(
+    a: arch::__m128i,
+    b: arch::__m128i,
+    keys: arch::__m128i,
+) -> arch::__m128i {
+    reduce128(a, b, keys)
+}
+
+unsafe fn reduce128(a: arch::__m128i, b: arch::__m128i, keys: arch::__m128i) -> arch::__m128i {
+    let t1 = arch::_mm_clmulepi64_si128(a, keys, 0x00);
+    let t2 = arch::_mm_clmulepi64_si128(a, keys, 0x11);
+    arch::_mm_xor_si128(arch::_mm_xor_si128(b, t1), t2)
+}