main.zig

const std = @import("std");

fn eq(comptime T: type, comptime len: usize, a: []const T, b: []const T) bool {
    if (len != a.len or len != b.len) return false;
    if (a.ptr == b.ptr) return true;

    const x16code = comptime blk: {
        var i: usize = 0;
        var buf = [_]u8{0} ** 4096;
        var code = std.io.fixedBufferStream(&buf);

        while (i + 16 <= len) : (i += 16) {
            std.fmt.format(code.outStream(),
                \\ vmovups {}(%[a]), %[s];
                \\ vmovups {}(%[b]), %[t];
                \\ vpxor %[s], %[t], %[t];
                \\ vpor %[t], %[u], %[u];
            , .{ i, i }) catch unreachable;
        }
        break :blk code.buffer;
    };
    var r: u128 = 0;
    var s: u128 = 0;
    var t: u128 = 0;
    var u: u128 = 0;
    comptime const code =
        \\ vpxor %[u], %[u], %[u];
    ++ x16code ++
        \\ vpxor %[s], %[s], %[s];      
        \\ vpcmpeqd %[s], %[u], %[s];  
        \\ vpmovmskb %[s], %[ret];
    ;

    const ret = asm volatile (code
        : [ret] "=r" (-> u64)
        : [a] "r" (&a),
          [b] "r" (&b),
          [s] "x" (&s),
          [t] "x" (&t),
          [u] "x" (&u)
    );
    std.debug.print("{X}\n", .{ret});

    return true;
}

pub fn main() anyerror!void {
    var a = [_]u8{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
    var b = [_]u8{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };

    _ = eq(u8, 16, &a, &b);
}