user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<lubksb>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x28(%rbp)
  mov    %esi,-0x2c(%rbp)
  mov    %rdx,-0x38(%rbp)
  mov    %rcx,-0x40(%rbp)
  movl   $0xffffffff,-0x14(%rbp)
  movl   $0x0,-0x18(%rbp)
  jmp    L62
L107:
  mov    -0x18(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x38(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  mov    %eax,-0xc(%rbp)
  mov    -0xc(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x8(%rbp)
  mov    -0x18(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rax,%rdx
  mov    -0xc(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rcx
  mov    -0x40(%rbp),%rax
  add    %rcx,%rax
  movsd  (%rdx),%xmm0
  movsd  %xmm0,(%rax)
  cmpl   $0x0,-0x14(%rbp)
  js     L12
  mov    -0x14(%rbp),%eax
  mov    %eax,-0x10(%rbp)
  jmp    L68
L110:
  mov    -0x10(%rbp),%eax
  imul   -0x2c(%rbp),%eax
  mov    %eax,%edx
  mov    -0x18(%rbp),%eax
  add    %edx,%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  mov    -0x10(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mulsd  %xmm0,%xmm1
  movsd  -0x8(%rbp),%xmm0
  subsd  %xmm1,%xmm0
  movsd  %xmm0,-0x8(%rbp)
  addl   $0x1,-0x10(%rbp)
L68:
  mov    -0x10(%rbp),%eax
  cmp    -0x18(%rbp),%eax
  jl     L110
  jmp    L69
L12:
  pxor   %xmm0,%xmm0
  ucomisd -0x8(%rbp),%xmm0
  jp     L34
  pxor   %xmm0,%xmm0
  ucomisd -0x8(%rbp),%xmm0
  je     L69
L34:
  mov    -0x18(%rbp),%eax
  mov    %eax,-0x14(%rbp)
L69:
  mov    -0x18(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  -0x8(%rbp),%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x18(%rbp)
L62:
  mov    -0x18(%rbp),%eax
  cmp    -0x2c(%rbp),%eax
  jl     L107
  mov    -0x2c(%rbp),%eax
  sub    $0x1,%eax
  mov    %eax,-0x18(%rbp)
  jmp    L4
L28:
  mov    -0x18(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x8(%rbp)
  mov    -0x18(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x10(%rbp)
  jmp    L56
L116:
  mov    -0x10(%rbp),%eax
  imul   -0x2c(%rbp),%eax
  mov    %eax,%edx
  mov    -0x18(%rbp),%eax
  add    %edx,%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  mov    -0x10(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mulsd  %xmm0,%xmm1
  movsd  -0x8(%rbp),%xmm0
  subsd  %xmm1,%xmm0
  movsd  %xmm0,-0x8(%rbp)
  addl   $0x1,-0x10(%rbp)
L56:
  mov    -0x10(%rbp),%eax
  cmp    -0x2c(%rbp),%eax
  jl     L116
  mov    -0x18(%rbp),%eax
  imul   -0x2c(%rbp),%eax
  mov    %eax,%edx
  mov    -0x18(%rbp),%eax
  add    %edx,%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  mov    -0x18(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  -0x8(%rbp),%xmm0
  divsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  subl   $0x1,-0x18(%rbp)
L4:
  cmpl   $0x0,-0x18(%rbp)
  jns    L28
  nop
  nop
  pop    %rbp
  ret
```

assistant: ```c
void lubksb(const double *A, int n, const int *indx, double *b) {
  double s;
  int i, ii = -1, ip, j;
  for (i = 0; i < n; ++i) {
    ip = indx[i];
    s = b[ip];
    b[ip] = b[i];
    if (ii >= 0) {
      for (j = ii; j < i; ++j) {
        s -= A[i + j * n] * b[j];
      }
    } else if (s) {
      ii = i;
    }
    b[i] = s;
  }
  for (i = n - 1; i >= 0; --i) {
    s = b[i];
    for (j = i + 1; j < n; ++j) {
      s -= A[i + j * n] * b[j];
    }
    b[i] = s / A[i + i * n];
  }
}
```