Fix tests/codegen/uninhabited-transparent-return-abi.rs test failure on riscv64

Author: CaiWeiran

tests/codegen/uninhabited-transparent-return-abi-generic.rs

@@ -0,0 +1,45 @@
+//@ compile-flags: -Copt-level=3
+//@ ignore-riscv64
+
+// See https://github.com/rust-lang/rust/issues/135802
+
+#![crate_type = "lib"]
+
+enum Void {}
+
+// Should be ABI-compatible with T, but wasn't prior to the PR adding this test.
+#[repr(transparent)]
+struct NoReturn<T>(T, Void);
+
+// Returned by invisible reference (in most ABIs)
+#[allow(dead_code)]
+struct Large(u64, u64, u64);
+
+extern "Rust" {
+    fn opaque() -> NoReturn<Large>;
+    fn opaque_with_arg(rsi: u32) -> NoReturn<Large>;
+}
+
+// CHECK-LABEL: @test_uninhabited_ret_by_ref
+#[no_mangle]
+pub fn test_uninhabited_ret_by_ref() {
+    // CHECK: %_1 = alloca [24 x i8], align {{8|4}}
+    // CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %_1)
+    // CHECK-NEXT: call void @opaque({{.*}} sret([24 x i8]) {{.*}} %_1) #2
+    // CHECK-NEXT: unreachable
+    unsafe {
+        opaque();
+    }
+}
+
+// CHECK-LABEL: @test_uninhabited_ret_by_ref_with_arg
+#[no_mangle]
+pub fn test_uninhabited_ret_by_ref_with_arg(rsi: u32) {
+    // CHECK: %_2 = alloca [24 x i8], align {{8|4}}
+    // CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %_2)
+    // CHECK-NEXT: call void @opaque_with_arg({{.*}} sret([24 x i8]) {{.*}} %_2, i32 noundef %rsi) #2
+    // CHECK-NEXT: unreachable
+    unsafe {
+        opaque_with_arg(rsi);
+    }
+}

tests/codegen/uninhabited-transparent-return-abi-riscv64.rs

@@ -0,0 +1,45 @@
+//@ compile-flags: -Copt-level=3
+//@ only-riscv64
+
+// See https://github.com/rust-lang/rust/issues/135802
+
+#![crate_type = "lib"]
+
+enum Void {}
+
+// Should be ABI-compatible with T, but wasn't prior to the PR adding this test.
+#[repr(transparent)]
+struct NoReturn<T>(T, Void);
+
+// Returned by invisible reference (in most ABIs)
+#[allow(dead_code)]
+struct Large(u64, u64, u64);
+
+extern "Rust" {
+    fn opaque() -> NoReturn<Large>;
+    fn opaque_with_arg(rsi: u32) -> NoReturn<Large>;
+}
+
+// CHECK-LABEL: @test_uninhabited_ret_by_ref
+#[no_mangle]
+pub fn test_uninhabited_ret_by_ref() {
+    // CHECK: %_1 = alloca [24 x i8], align {{8|4}}
+    // CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %_1)
+    // CHECK-NEXT: call void @opaque({{.*}} sret([24 x i8]) {{.*}} %_1) #2
+    // CHECK-NEXT: unreachable
+    unsafe {
+        opaque();
+    }
+}
+
+// CHECK-LABEL: @test_uninhabited_ret_by_ref_with_arg
+#[no_mangle]
+pub fn test_uninhabited_ret_by_ref_with_arg(rsi: u32) {
+    // CHECK: %_2 = alloca [24 x i8], align {{8|4}}
+    // CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %_2)
+    // CHECK-NEXT: call void @opaque_with_arg({{.*}} sret([24 x i8]) {{.*}} %_2, i32 noundef signext %rsi) #2
+    // CHECK-NEXT: unreachable
+    unsafe {
+        opaque_with_arg(rsi);
+    }
+}