From df1cd62720138122a9389d78df5187af7c577e24 Mon Sep 17 00:00:00 2001
From: dweiller <4678790+dweiller@users.noreply.github.com>
Date: Sun, 26 Jan 2025 02:31:32 +1100
Subject: [PATCH] compiler-rt: ensure memcpy Element has no unused bytes

---
 lib/compiler_rt/memcpy.zig | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/compiler_rt/memcpy.zig b/lib/compiler_rt/memcpy.zig
index d67a6e766a..7025768dd5 100644
--- a/lib/compiler_rt/memcpy.zig
+++ b/lib/compiler_rt/memcpy.zig
@@ -18,16 +18,18 @@ comptime {
     }
 }
 
-const Element = if (std.simd.suggestVectorLength(u8)) |vec_size|
-    @Type(.{ .vector = .{
-        .child = u8,
-        .len = vec_size,
-    } })
-else
-    usize;
+const Element = Element: {
+    if (std.simd.suggestVectorLength(u8)) |vec_size| {
+        const Vec = @Vector(vec_size, u8);
+
+        if (@sizeOf(Vec) == vec_size and std.math.isPowerOfTwo(vec_size)) {
+            break :Element Vec;
+        }
+    }
+    break :Element usize;
+};
 
 comptime {
-    assert(@sizeOf(Element) >= @alignOf(Element));
     assert(std.math.isPowerOfTwo(@sizeOf(Element)));
 }