user: 请显示与下面列出的汇编代码相匹配的C语言实现：

```asm
<widescreen>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  add    $0xffffffffffffff80,%rsp
  mov    %rdi,-0x78(%rbp)
  mov    %rsi,-0x80(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  movq   $0x0,-0x20(%rbp)
  jmp    L32
L52:
  movq   $0x0,-0x28(%rbp)
  movq   $0x0,-0x18(%rbp)
  jmp    L53
L50:
  mov    -0x28(%rbp),%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x80(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%rdx
  mov    -0x20(%rbp),%rax
  shl    $0x3,%rax
  add    %rdx,%rax
  mov    -0x28(%rbp),%rcx
  mov    -0x18(%rbp),%rdx
  add    %rcx,%rdx
  lea    0x0(,%rdx,8),%rcx
  mov    -0x78(%rbp),%rdx
  add    %rcx,%rdx
  mov    (%rdx),%rcx
  mov    -0x20(%rbp),%rdx
  shl    $0x3,%rdx
  add    %rcx,%rdx
  mov    (%rax),%rax
  mov    %rax,(%rdx)
  mov    -0x28(%rbp),%rcx
  movabs $0xaaaaaaaaaaaaaaab,%rdx
  mov    %rcx,%rax
  mul    %rdx
  mov    %rdx,%rax
  shr    %rax
  mov    %rax,%rdx
  add    %rdx,%rdx
  add    %rax,%rdx
  mov    %rcx,%rax
  sub    %rdx,%rax
  cmp    $0x2,%rax
  jne    L20
  mov    -0x28(%rbp),%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x80(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%rdx
  mov    -0x20(%rbp),%rax
  shl    $0x3,%rax
  add    %rdx,%rax
  mov    (%rax),%rax
  mov    %rax,-0x10(%rbp)
  cmpq   $0x27e,-0x28(%rbp)
  ja     L9
  lea    -0x50(%rbp),%rdi
  lea    -0x58(%rbp),%rcx
  lea    -0x60(%rbp),%rdx
  lea    -0x68(%rbp),%rsi
  mov    -0x10(%rbp),%rax
  mov    %rdi,%r8
  mov    %rax,%rdi
  call   <subpixels@plt>
  mov    -0x28(%rbp),%rax
  add    $0x1,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x80(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%rdx
  mov    -0x20(%rbp),%rax
  shl    $0x3,%rax
  add    %rdx,%rax
  mov    (%rax),%rax
  lea    -0x30(%rbp),%rdi
  lea    -0x38(%rbp),%rcx
  lea    -0x40(%rbp),%rdx
  lea    -0x48(%rbp),%rsi
  mov    %rdi,%r8
  mov    %rax,%rdi
  call   <subpixels@plt>
  mov    -0x60(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  shr    %rax
  shl    $0x10,%rax
  mov    %rax,-0x60(%rbp)
  mov    -0x58(%rbp),%rdx
  mov    -0x38(%rbp),%rax
  add    %rdx,%rax
  shr    %rax
  shl    $0x8,%rax
  mov    %rax,-0x58(%rbp)
  mov    -0x50(%rbp),%rdx
  mov    -0x30(%rbp),%rax
  add    %rdx,%rax
  shr    %rax
  mov    %rax,-0x50(%rbp)
  mov    -0x60(%rbp),%rdx
  mov    -0x58(%rbp),%rax
  or     %rax,%rdx
  mov    -0x50(%rbp),%rax
  or     %rdx,%rax
  mov    %rax,-0x10(%rbp)
L9:
  addq   $0x1,-0x18(%rbp)
  mov    -0x18(%rbp),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x78(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%rdx
  mov    -0x20(%rbp),%rax
  shl    $0x3,%rax
  add    %rax,%rdx
  mov    -0x10(%rbp),%rax
  mov    %rax,(%rdx)
L20:
  addq   $0x1,-0x28(%rbp)
L53:
  cmpq   $0x27f,-0x28(%rbp)
  jbe    L50
  addq   $0x1,-0x20(%rbp)
L32:
  cmpq   $0x1df,-0x20(%rbp)
  jbe    L52
  nop
  mov    -0x8(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L58
  call   <__stack_chk_fail@plt>
L58:
  leave
  ret
```

assistant: ```c
void widescreen(unsigned long *restrict *restrict rc, unsigned long *restrict *restrict img) {
  unsigned long x, y, e, rgb;
  unsigned long a1, r1, g1, b1, a2, r2, g2, b2;
  for (y = 0; y < 480; y++)
    for (x = 0, e = 0; x < 640; x++)
      if (rc[x + e][y] = img[x][y], x % 3 == 2) {
        if (rgb = img[x][y], x < 640 - 1) {
          subpixels(rgb, &a1, &r1, &g1, &b1);
          subpixels(img[x + 1][y], &a2, &r2, &g2, &b2);
          r1 = ((r1 + r2) / 2) << 16;
          g1 = ((g1 + g2) / 2) << 8;
          b1 = ((b1 + b2) / 2) << 0;
          rgb = r1 | g1 | b1;
        }
        rc[x + ++e][y] = rgb;
      }
}
```