user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<mat>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x20,%rsp
  mov    %rdi,-0x18(%rbp)
  mov    %esi,-0x1c(%rbp)
  mov    %edx,-0x20(%rbp)
  mov    -0x20(%rbp),%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  cmp    %eax,-0x1c(%rbp)
  jne    L85
  mov    $0x0,%eax
  jmp    L44
L85:
  mov    -0x1c(%rbp),%eax
  mov    %eax,-0x4(%rbp)
  jmp    L67
L91:
  mov    D15(%rip),%edx
  lea    0x1(%rdx),%eax
  mov    %eax,D25(%rip)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rcx
  mov    %rcx,%rax
  shl    $0x2,%rax
  add    %rcx,%rax
  lea    0x0(,%rax,4),%rcx
  add    %rcx,%rax
  shl    $0x3,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rax,%rcx
  mov    -0x4(%rbp),%eax
  cltq
  mov    %edx,(%rcx,%rax,4)
  addl   $0x1,-0x4(%rbp)
L67:
  mov    -0x20(%rbp),%eax
  sub    -0x1c(%rbp),%eax
  cmp    %eax,-0x4(%rbp)
  jl     L91
  mov    -0x1c(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x4(%rbp)
  jmp    L61
L29:
  mov    D25(%rip),%edx
  lea    0x1(%rdx),%eax
  mov    %eax,D25(%rip)
  mov    -0x4(%rbp),%eax
  movslq %eax,%rcx
  mov    %rcx,%rax
  shl    $0x2,%rax
  add    %rcx,%rax
  lea    0x0(,%rax,4),%rcx
  add    %rcx,%rax
  shl    $0x3,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rax,%rcx
  mov    -0x20(%rbp),%eax
  sub    -0x1c(%rbp),%eax
  sub    $0x1,%eax
  cltq
  mov    %edx,(%rcx,%rax,4)
  addl   $0x1,-0x4(%rbp)
L61:
  mov    -0x20(%rbp),%eax
  sub    -0x1c(%rbp),%eax
  cmp    %eax,-0x4(%rbp)
  jl     L29
  mov    -0x20(%rbp),%eax
  sub    -0x1c(%rbp),%eax
  sub    $0x2,%eax
  mov    %eax,-0x4(%rbp)
  jmp    L33
L57:
  mov    D25(%rip),%edx
  lea    0x1(%rdx),%eax
  mov    %eax,D25(%rip)
  mov    -0x20(%rbp),%eax
  sub    -0x1c(%rbp),%eax
  movslq %eax,%rcx
  mov    %rcx,%rax
  shl    $0x2,%rax
  add    %rcx,%rax
  lea    0x0(,%rax,4),%rcx
  add    %rcx,%rax
  shl    $0x3,%rax
  lea    -0xc8(%rax),%rcx
  mov    -0x18(%rbp),%rax
  add    %rax,%rcx
  mov    -0x4(%rbp),%eax
  cltq
  mov    %edx,(%rcx,%rax,4)
  subl   $0x1,-0x4(%rbp)
L33:
  mov    -0x4(%rbp),%eax
  cmp    -0x1c(%rbp),%eax
  jge    L57
  mov    -0x20(%rbp),%eax
  sub    $0x2,%eax
  sub    -0x1c(%rbp),%eax
  mov    %eax,-0x4(%rbp)
  jmp    L55
L46:
  mov    D25(%rip),%edx
  lea    0x1(%rdx),%eax
  mov    %eax,D25(%rip)
  mov    -0x4(%rbp),%eax
  movslq %eax,%rcx
  mov    %rcx,%rax
  shl    $0x2,%rax
  add    %rcx,%rax
  lea    0x0(,%rax,4),%rcx
  add    %rcx,%rax
  shl    $0x3,%rax
  mov    %rax,%rcx
  mov    -0x18(%rbp),%rax
  add    %rax,%rcx
  mov    -0x1c(%rbp),%eax
  cltq
  mov    %edx,(%rcx,%rax,4)
  subl   $0x1,-0x4(%rbp)
L55:
  mov    -0x4(%rbp),%eax
  cmp    -0x1c(%rbp),%eax
  jg     L46
  mov    -0x1c(%rbp),%eax
  lea    0x1(%rax),%ecx
  mov    -0x20(%rbp),%edx
  mov    -0x18(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <mat>
  mov    $0x0,%eax
L44:
  leave
  ret
```

assistant: ```c
int mat(int a[][50], int i, int n) {
  static int k = 1;
  int j;
  if (i == n / 2)
    return 0;
  for (j = i; j < n - i; j++)
    a[i][j] = k++;
  for (j = i + 1; j < n - i; j++)
    a[j][n - i - 1] = k++;
  for (j = n - i - 2; j >= i; j--)
    a[n - i - 1][j] = k++;
  for (j = n - 2 - i; j > i; j--)
    a[j][i] = k++;
  mat(a, i + 1, n);
  return 0;
}
```