manually vectorize

alion02 · Dec 18, 2024 · dcffa1a · dcffa1a
1 parent d73aef6
commit dcffa1a
Showing 1 changed file with 8 additions and 12 deletions.
diff --git a/src/day18.rs b/src/day18.rs
@@ -44,18 +44,14 @@ unsafe fn inner1(s: &[u8]) -> u32 {
     let mut ptr = s.as_ptr().cast::<i8x16>();
     let lut = &LUT;
 
-    let map: &mut [u8; 73 * 72 / 8] = &mut array::from_fn(|i| {
-        if (72 / 8..72 * 72 / 8).contains(&i) {
-            if i % 9 == 8 {
-                128
-            } else {
-                0
-            }
-        } else {
-            !0
-        }
-    });
-    let map = map.as_mut_ptr();
+    static mut MAP: [i8; 73 * 72 / 8] = [-1; 73 * 72 / 8];
+
+    let map = MAP.as_mut_ptr();
+    for i in 1..72 {
+        map.add(i * 72 / 8).cast::<i8x16>().write_unaligned(i8x16::from_array([
+            0, 0, 0, 0, 0, 0, 0, 0, -128, -1, -1, -1, -1, -1, -1, -1,
+        ]));
+    }
 
     macro_rules! bts {
         ($idx:expr) => {