From e4d33640d03a5dc8cee30b284ca46a449cdc29dd Mon Sep 17 00:00:00 2001
From: Folkert de Vries <folkert@folkertdev.nl>
Date: Wed, 19 Feb 2025 23:16:37 +0100
Subject: [PATCH] add `vec_reve`

---
 .../stdarch/crates/core_arch/src/s390x/vector.rs  | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/library/stdarch/crates/core_arch/src/s390x/vector.rs b/library/stdarch/crates/core_arch/src/s390x/vector.rs
index 795e42638466..db0d228bca5d 100644
--- a/library/stdarch/crates/core_arch/src/s390x/vector.rs
+++ b/library/stdarch/crates/core_arch/src/s390x/vector.rs
@@ -1212,6 +1212,21 @@ mod sealed {
         unsafe fn vec_reve(self) -> Self;
     }
 
+    #[repr(simd)]
+    struct ReverseMask<const N: usize>([u32; N]);
+
+    impl<const N: usize> ReverseMask<N> {
+        const fn new() -> Self {
+            let mut index = [0; N];
+            let mut i = 0;
+            while i < N {
+                index[i] = (N - i - 1) as u32;
+                i += 1;
+            }
+            ReverseMask(index)
+        }
+    }
+
     macro_rules! impl_reve {
         ($($ty:ident, $fun:ident, $instr:ident),*) => {
             $(