Add a run-pass test for SIMD masked load & store

Author: farnoy

tests/ui/simd/masked-load-store.rs

@@ -0,0 +1,31 @@
+// run-pass
+#![feature(repr_simd, platform_intrinsics)]
+
+extern "platform-intrinsic" {
+    fn simd_masked_load<T, P, M>(values: T, pointer: P, mask: M) -> T;
+    fn simd_masked_store<T, P, M>(values: T, pointer: P, mask: M) -> ();
+}
+
+#[derive(Copy, Clone)]
+#[repr(simd)]
+struct Simd<T, const N: usize>([T; N]);
+
+fn main() {
+    unsafe {
+        let a = Simd::<u8, 4>([0, 1, 2, 3]);
+        let b_src = [4u8, 5, 6, 7];
+        let b_default = Simd::<u8, 4>([9; 4]);
+        let b: Simd::<u8, 4> = simd_masked_load(
+            b_default,
+            b_src.as_ptr(),
+            Simd::<i8, 4>([-1, 0, -1, -1])
+        );
+
+        let mut output = [u8::MAX; 5];
+
+        simd_masked_store(a, output.as_mut_ptr(), Simd::<i8, 4>([-1, -1, -1, 0]));
+        assert_eq!(&output, &[0, 1, 2, u8::MAX, u8::MAX]);
+        simd_masked_store(b, output[1..].as_mut_ptr(), Simd::<i8, 4>([0, -1, -1, 0]));
+        assert_eq!(&output, &[0, 1, 9, 6, u8::MAX]);
+    }
+}