also test directly calling simd_select_bitmask

Author: RalfJung

src/tools/miri/tests/pass/portable-simd.rs

@@ -3,10 +3,6 @@
 #![allow(incomplete_features, internal_features)]
 use std::simd::{prelude::*, StdFloat};
 
-extern "platform-intrinsic" {
-    pub(crate) fn simd_bitmask<T, U>(x: T) -> U;
-}
-
 fn simd_ops_f32() {
     let a = f32x4::splat(10.0);
     let b = f32x4::from_array([1.0, 2.0, 3.0, -4.0]);
@@ -218,6 +214,11 @@ fn simd_ops_i32() {
 }
 
 fn simd_mask() {
+    extern "platform-intrinsic" {
+        pub(crate) fn simd_bitmask<T, U>(x: T) -> U;
+        pub(crate) fn simd_select_bitmask<M, T>(m: M, yes: T, no: T) -> T;
+    }
+
     let intmask = Mask::from_int(i32x4::from_array([0, -1, 0, 0]));
     assert_eq!(intmask, Mask::from_array([false, true, false, false]));
     assert_eq!(intmask.to_array(), [false, true, false, false]);
@@ -286,6 +287,40 @@ fn simd_mask() {
             true, true, true,
         ]),
     );
+
+    // Also directly call simd_select_bitmask, to test both kinds of argument types.
+    unsafe {
+        // These masks are exactly the results we got out above in the `simd_bitmask` tests.
+        let selected1 = simd_select_bitmask::<u16, _>(
+            if cfg!(target_endian = "little") { 0b1010001101001001 } else { 0b1001001011000101 },
+            i32x16::splat(1), // yes
+            i32x16::splat(0), // no
+        );
+        let selected2 = simd_select_bitmask::<[u8; 2], _>(
+            if cfg!(target_endian = "little") {
+                [0b01001001, 0b10100011]
+            } else {
+                [0b10010010, 0b11000101]
+            },
+            i32x16::splat(1), // yes
+            i32x16::splat(0), // no
+        );
+        assert_eq!(selected1, i32x16::from_array([1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1]));
+        assert_eq!(selected2, selected1);
+        // Also try masks less than a byte long.
+        let selected1 = simd_select_bitmask::<u8, _>(
+            if cfg!(target_endian = "little") { 0b1000 } else { 0b0001 },
+            i32x4::splat(1), // yes
+            i32x4::splat(0), // no
+        );
+        let selected2 = simd_select_bitmask::<[u8; 1], _>(
+            if cfg!(target_endian = "little") { [0b1000] } else { [0b0001] },
+            i32x4::splat(1), // yes
+            i32x4::splat(0), // no
+        );
+        assert_eq!(selected1, i32x4::from_array([0, 0, 0, 1]));
+        assert_eq!(selected2, selected1);
+    }
 }
 
 fn simd_cast() {