user: 请从给定的汇编指令推导出C源代码：

```asm
<plot4_palettized_even_clipped>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x30,%rsp
  mov    %rdi,-0x18(%rbp)
  mov    %rsi,-0x20(%rbp)
  mov    %edx,-0x24(%rbp)
  mov    %ecx,%eax
  mov    %r8d,-0x2c(%rbp)
  mov    %r9d,-0x30(%rbp)
  mov    %al,-0x28(%rbp)
  cmpl   $0x0,-0x30(%rbp)
  jne    L5
  mov    -0x2c(%rbp),%eax
  shl    $0x3,%eax
  mov    %eax,%edx
  mov    0x20(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x2c(%rbp),%eax
  shl    $0x3,%eax
  mov    %eax,%eax
  lea    0x2(%rax),%rcx
  mov    0x20(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x8,%eax
  add    %eax,%edx
  mov    -0x2c(%rbp),%eax
  shl    $0x3,%eax
  mov    %eax,%eax
  lea    0x4(%rax),%rcx
  mov    0x20(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x10,%eax
  add    %eax,%edx
  mov    -0x2c(%rbp),%eax
  shl    $0x3,%eax
  mov    %eax,%eax
  lea    0x6(%rax),%rcx
  mov    0x20(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x18,%eax
  add    %edx,%eax
  mov    %eax,-0x4(%rbp)
  jmp    L4
L5:
  mov    -0x2c(%rbp),%eax
  shl    $0x3,%eax
  mov    %eax,%edx
  mov    0x20(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x18,%eax
  mov    %eax,%edx
  mov    -0x2c(%rbp),%eax
  shl    $0x3,%eax
  mov    %eax,%eax
  lea    0x2(%rax),%rcx
  mov    0x20(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x10,%eax
  add    %eax,%edx
  mov    -0x2c(%rbp),%eax
  shl    $0x3,%eax
  mov    %eax,%eax
  lea    0x4(%rax),%rcx
  mov    0x20(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  shl    $0x8,%eax
  add    %eax,%edx
  mov    -0x2c(%rbp),%eax
  shl    $0x3,%eax
  mov    %eax,%eax
  lea    0x6(%rax),%rcx
  mov    0x20(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  add    %edx,%eax
  mov    %eax,-0x4(%rbp)
L4:
  movzbl -0x28(%rbp),%ecx
  mov    -0x4(%rbp),%r8d
  mov    -0x24(%rbp),%edx
  mov    -0x20(%rbp),%rsi
  mov    -0x18(%rbp),%rax
  sub    $0x8,%rsp
  mov    0x18(%rbp),%edi
  push   %rdi
  mov    0x10(%rbp),%r9d
  mov    %rax,%rdi
  call   <plot4_palettized_clipped_work@plt>
  add    $0x10,%rsp
  nop
  leave
  ret
```

assistant: ```c
void plot4_palettized_even_clipped(unsigned char (*screen1)[2], unsigned char (*screen2)[2], unsigned output_surface_offset, unsigned char depth, unsigned tile_address, int xflip, unsigned palette_mask, unsigned clip_mask, const void *cache) {
  unsigned pixels;
  if (!xflip) {
    pixels = (unsigned)*((unsigned char *)cache + tile_address * 8 + 0) + ((unsigned)*((unsigned char *)cache + tile_address * 8 + 2) << 8) + ((unsigned)*((unsigned char *)cache + tile_address * 8 + 4) << 16) + ((unsigned)*((unsigned char *)cache + tile_address * 8 + 6) << 24);
  } else {
    pixels = ((unsigned)*((unsigned char *)cache + tile_address * 8 + 0) << 24) + ((unsigned)*((unsigned char *)cache + tile_address * 8 + 2) << 16) + ((unsigned)*((unsigned char *)cache + tile_address * 8 + 4) << 8) + (unsigned)*((unsigned char *)cache + tile_address * 8 + 6);
  }
  plot4_palettized_clipped_work(screen1, screen2, output_surface_offset, depth, pixels, palette_mask, clip_mask);
}
```