user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<vp9_sub_pixel_variance16x2_sse2>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x50,%rsp
  mov    %rdi,-0x28(%rbp)
  mov    %esi,-0x2c(%rbp)
  mov    %edx,-0x30(%rbp)
  mov    %ecx,-0x34(%rbp)
  mov    %r8,-0x40(%rbp)
  mov    %r9d,-0x38(%rbp)
  mov    0x10(%rbp),%rax
  mov    %rax,-0x48(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  cmpl   $0x8,-0x30(%rbp)
  jne    L24
  cmpl   $0x0,-0x34(%rbp)
  jne    L24
  lea    -0x18(%rbp),%r8
  mov    -0x38(%rbp),%ecx
  mov    -0x40(%rbp),%rdx
  mov    -0x2c(%rbp),%esi
  mov    -0x28(%rbp),%rax
  sub    $0x8,%rsp
  lea    -0x10(%rbp),%rdi
  push   %rdi
  mov    %r8,%r9
  mov    $0x2,%r8d
  mov    %rax,%rdi
  call   <vp9_half_horiz_variance16x_h_sse2@plt>
  add    $0x10,%rsp
  jmp    L65
L24:
  cmpl   $0x0,-0x30(%rbp)
  jne    L16
  cmpl   $0x8,-0x34(%rbp)
  jne    L16
  lea    -0x18(%rbp),%r8
  mov    -0x38(%rbp),%ecx
  mov    -0x40(%rbp),%rdx
  mov    -0x2c(%rbp),%esi
  mov    -0x28(%rbp),%rax
  sub    $0x8,%rsp
  lea    -0x10(%rbp),%rdi
  push   %rdi
  mov    %r8,%r9
  mov    $0x2,%r8d
  mov    %rax,%rdi
  call   <vp9_half_vert_variance16x_h_sse2@plt>
  add    $0x10,%rsp
  jmp    L65
L16:
  cmpl   $0x8,-0x30(%rbp)
  jne    L17
  cmpl   $0x8,-0x34(%rbp)
  jne    L17
  lea    -0x18(%rbp),%r8
  mov    -0x38(%rbp),%ecx
  mov    -0x40(%rbp),%rdx
  mov    -0x2c(%rbp),%esi
  mov    -0x28(%rbp),%rax
  sub    $0x8,%rsp
  lea    -0x10(%rbp),%rdi
  push   %rdi
  mov    %r8,%r9
  mov    $0x2,%r8d
  mov    %rax,%rdi
  call   <vp9_half_horiz_vert_variance16x_h_sse2@plt>
  add    $0x10,%rsp
  jmp    L65
L17:
  mov    -0x30(%rbp),%r8d
  mov    -0x38(%rbp),%ecx
  mov    -0x40(%rbp),%rdx
  mov    -0x2c(%rbp),%esi
  mov    -0x28(%rbp),%rax
  sub    $0x8,%rsp
  lea    -0x10(%rbp),%rdi
  push   %rdi
  lea    -0x18(%rbp),%rdi
  push   %rdi
  mov    -0x34(%rbp),%edi
  push   %rdi
  mov    %r8d,%r9d
  mov    $0x2,%r8d
  mov    %rax,%rdi
  call   <vp9_filter_block2d_bil_var_sse2@plt>
  add    $0x20,%rsp
  mov    -0x40(%rbp),%rax
  lea    0x8(%rax),%rsi
  mov    -0x28(%rbp),%rax
  lea    0x8(%rax),%rdi
  mov    -0x30(%rbp),%r8d
  mov    -0x38(%rbp),%edx
  mov    -0x2c(%rbp),%eax
  sub    $0x8,%rsp
  lea    -0xc(%rbp),%rcx
  push   %rcx
  lea    -0x14(%rbp),%rcx
  push   %rcx
  mov    -0x34(%rbp),%ecx
  push   %rcx
  mov    %r8d,%r9d
  mov    $0x2,%r8d
  mov    %edx,%ecx
  mov    %rsi,%rdx
  mov    %eax,%esi
  call   <vp9_filter_block2d_bil_var_sse2@plt>
  add    $0x20,%rsp
  mov    -0x18(%rbp),%edx
  mov    -0x14(%rbp),%eax
  add    %edx,%eax
  mov    %eax,-0x18(%rbp)
  mov    -0x10(%rbp),%edx
  mov    -0xc(%rbp),%eax
  add    %edx,%eax
  mov    %eax,-0x10(%rbp)
L65:
  mov    -0x10(%rbp),%edx
  mov    -0x48(%rbp),%rax
  mov    %edx,(%rax)
  mov    -0x10(%rbp),%eax
  mov    -0x18(%rbp),%edx
  mov    %edx,%ecx
  mov    -0x18(%rbp),%edx
  imul   %ecx,%edx
  shr    $0x5,%edx
  sub    %edx,%eax
  mov    -0x8(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L85
  call   <__stack_chk_fail@plt>
L85:
  leave
  ret
```

assistant: ```c
unsigned int vp9_sub_pixel_variance16x2_sse2(const unsigned char *src_ptr, int src_pixels_per_line, int xoffset, int yoffset, const unsigned char *dst_ptr, int dst_pixels_per_line, unsigned int *sse) {
  int xsum0, xsum1;
  unsigned int xxsum0, xxsum1;
  if (xoffset == 8 && yoffset == 0) {
    vp9_half_horiz_variance16x_h_sse2(src_ptr, src_pixels_per_line, dst_ptr, dst_pixels_per_line, 2, &xsum0, &xxsum0);
  } else if (xoffset == 0 && yoffset == 8) {
    vp9_half_vert_variance16x_h_sse2(src_ptr, src_pixels_per_line, dst_ptr, dst_pixels_per_line, 2, &xsum0, &xxsum0);
  } else if (xoffset == 8 && yoffset == 8) {
    vp9_half_horiz_vert_variance16x_h_sse2(src_ptr, src_pixels_per_line, dst_ptr, dst_pixels_per_line, 2, &xsum0, &xxsum0);
  } else {
    vp9_filter_block2d_bil_var_sse2(src_ptr, src_pixels_per_line, dst_ptr, dst_pixels_per_line, 2, xoffset, yoffset, &xsum0, &xxsum0);
    vp9_filter_block2d_bil_var_sse2(src_ptr + 8, src_pixels_per_line, dst_ptr + 8, dst_pixels_per_line, 2, xoffset, yoffset, &xsum1, &xxsum1);
    xsum0 += xsum1;
    xxsum0 += xxsum1;
  }
  *sse = xxsum0;
  return (xxsum0 - (((unsigned int)xsum0 * xsum0) >> 5));
}
```