1 files changed, 71 insertions, 0 deletions
diff --git a/tests/codegen-llvm/intrinsics/select_unpredictable.rs b/tests/codegen-llvm/intrinsics/select_unpredictable.rs
new file mode 100644
index 00000000000..ad7120c6fb8
--- /dev/null
+++ b/tests/codegen-llvm/intrinsics/select_unpredictable.rs
@@ -0,0 +1,71 @@
+//@ compile-flags: -Copt-level=3 -Zmerge-functions=disabled
+
+#![feature(core_intrinsics)]
+#![crate_type = "lib"]
+
+/* Test the intrinsic */
+
+#[no_mangle]
+pub fn test_int(p: bool, a: u64, b: u64) -> u64 {
+    // CHECK-LABEL: define{{.*}} @test_int
+    // CHECK: select i1 %p, i64 %a, i64 %b, !unpredictable
+    core::intrinsics::select_unpredictable(p, a, b)
+}
+
+#[no_mangle]
+pub fn test_pair(p: bool, a: (u64, u64), b: (u64, u64)) -> (u64, u64) {
+    // CHECK-LABEL: define{{.*}} @test_pair
+    // CHECK: select i1 %p, {{.*}}, !unpredictable
+    core::intrinsics::select_unpredictable(p, a, b)
+}
+
+struct Large {
+    e: [u64; 100],
+}
+
+#[no_mangle]
+pub fn test_struct(p: bool, a: Large, b: Large) -> Large {
+    // CHECK-LABEL: define{{.*}} @test_struct
+    // CHECK: select i1 %p, {{.*}}, !unpredictable
+    core::intrinsics::select_unpredictable(p, a, b)
+}
+
+// ZSTs should not need a `select` expression.
+#[no_mangle]
+pub fn test_zst(p: bool, a: (), b: ()) -> () {
+    // CHECK-LABEL: define{{.*}} @test_zst
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: ret void
+    core::intrinsics::select_unpredictable(p, a, b)
+}
+
+/* Test the user-facing version */
+
+#[no_mangle]
+pub fn test_int2(p: bool, a: u64, b: u64) -> u64 {
+    // CHECK-LABEL: define{{.*}} @test_int2
+    // CHECK: select i1 %p, i64 %a, i64 %b, !unpredictable
+    core::hint::select_unpredictable(p, a, b)
+}
+
+#[no_mangle]
+pub fn test_pair2(p: bool, a: (u64, u64), b: (u64, u64)) -> (u64, u64) {
+    // CHECK-LABEL: define{{.*}} @test_pair2
+    // CHECK: select i1 %p, {{.*}}, !unpredictable
+    core::hint::select_unpredictable(p, a, b)
+}
+
+#[no_mangle]
+pub fn test_struct2(p: bool, a: Large, b: Large) -> Large {
+    // CHECK-LABEL: define{{.*}} @test_struct2
+    // CHECK: select i1 %p, {{.*}}, !unpredictable
+    core::hint::select_unpredictable(p, a, b)
+}
+
+#[no_mangle]
+pub fn test_zst2(p: bool, a: (), b: ()) -> () {
+    // CHECK-LABEL: define{{.*}} @test_zst2
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: ret void
+    core::hint::select_unpredictable(p, a, b)
+}