user: 这段汇编代码用C语言表示是什么样的?

```asm
<libc_ldtos>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x70,%rsp
  mov    $0x20,%edi
  call   <malloc@plt>
  mov    %rax,-0x28(%rbp)
  mov    -0x28(%rbp),%rax
  movb   $0x0,(%rax)
  mov    -0x28(%rbp),%rax
  mov    %rax,-0x20(%rbp)
  movq   $0x0,-0x18(%rbp)
  movq   $0x0,-0x50(%rbp)
  movq   $0x0,-0x48(%rbp)
  movq   $0x0,-0x40(%rbp)
  movq   $0x0,-0x10(%rbp)
  movq   $0x0,-0x8(%rbp)
  movq   $0x0,-0x38(%rbp)
  movq   $0x0,-0x30(%rbp)
  fldt   0x10(%rbp)
  fldz
  fcomip %st(1),%st
  fstp   %st(0)
  jbe    L15
  mov    -0x50(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x50(%rbp)
  mov    %rax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movb   $0x2d,(%rax)
  fldt   0x10(%rbp)
  fchs
  fstpt  -0x70(%rbp)
  mov    -0x70(%rbp),%rax
  mov    -0x68(%rbp),%edx
  mov    %rax,0x10(%rbp)
  mov    %edx,0x18(%rbp)
L15:
  fldt   0x10(%rbp)
  fnstcw -0x52(%rbp)
  movzwl -0x52(%rbp),%eax
  or     $0xc,%ah
  mov    %ax,-0x54(%rbp)
  fldcw  -0x54(%rbp)
  fistpll -0x40(%rbp)
  fldcw  -0x52(%rbp)
  mov    -0x40(%rbp),%rax
  mov    %rax,-0x10(%rbp)
  cmpq   $0x0,-0x40(%rbp)
  jne    L89
  mov    -0x50(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x50(%rbp)
  mov    %rax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movb   $0x30,(%rax)
L89:
  mov    -0x50(%rbp),%rax
  mov    %rax,-0x48(%rbp)
  jmp    L77
L56:
  mov    -0x40(%rbp),%rcx
  movabs $0x6666666666666667,%rdx
  mov    %rcx,%rax
  imul   %rdx
  mov    %rdx,%rax
  sar    $0x2,%rax
  mov    %rcx,%rsi
  sar    $0x3f,%rsi
  sub    %rsi,%rax
  mov    %rax,%rdx
  mov    %rdx,%rax
  shl    $0x2,%rax
  add    %rdx,%rax
  add    %rax,%rax
  sub    %rax,%rcx
  mov    %rcx,%rdx
  mov    %rdx,-0x8(%rbp)
  mov    -0x40(%rbp),%rcx
  movabs $0x6666666666666667,%rdx
  mov    %rcx,%rax
  imul   %rdx
  mov    %rdx,%rax
  sar    $0x2,%rax
  sar    $0x3f,%rcx
  mov    %rcx,%rdx
  sub    %rdx,%rax
  mov    %rax,-0x40(%rbp)
  mov    -0x8(%rbp),%rax
  lea    0x30(%rax),%ecx
  mov    -0x48(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x48(%rbp)
  mov    %rax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  mov    %ecx,%edx
  mov    %dl,(%rax)
L77:
  cmpq   $0x0,-0x40(%rbp)
  jg     L56
  mov    -0x48(%rbp),%rax
  lea    -0x1(%rax),%rdx
  mov    %rdx,-0x48(%rbp)
  mov    %rax,-0x18(%rbp)
  jmp    L64
L70:
  mov    -0x48(%rbp),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movsbl %al,%edx
  mov    -0x50(%rbp),%rcx
  mov    -0x20(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <swap@plt>
  addq   $0x1,-0x50(%rbp)
  subq   $0x1,-0x48(%rbp)
L64:
  mov    -0x48(%rbp),%rax
  cmp    -0x50(%rbp),%rax
  jg     L70
  mov    -0x18(%rbp),%rax
  mov    %rax,-0x50(%rbp)
  fildll -0x10(%rbp)
  fldt   0x10(%rbp)
  fsubp  %st,%st(1)
  fstpt  0x10(%rbp)
  mov    -0x50(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x50(%rbp)
  mov    %rax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movb   $0x2e,(%rax)
  mov    $0x13,%eax
  sub    -0x50(%rbp),%rax
  mov    %rax,-0x30(%rbp)
  cmpq   $0x6,-0x30(%rbp)
  jg     L65
  movq   $0x7,-0x30(%rbp)
L65:
  movq   $0x0,-0x38(%rbp)
  jmp    L71
L62:
  fldt   0x10(%rbp)
  fldt   0xc92(%rip)        # 2000 <_fini+0xbe0>
  fmulp  %st,%st(1)
  fstpt  0x10(%rbp)
  fldt   0x10(%rbp)
  fnstcw -0x52(%rbp)
  movzwl -0x52(%rbp),%eax
  or     $0xc,%ah
  mov    %ax,-0x54(%rbp)
  fldcw  -0x54(%rbp)
  fistpll -0x70(%rbp)
  fldcw  -0x52(%rbp)
  mov    -0x70(%rbp),%rcx
  movabs $0x6666666666666667,%rdx
  mov    %rcx,%rax
  imul   %rdx
  mov    %rdx,%rax
  sar    $0x2,%rax
  mov    %rcx,%rdx
  sar    $0x3f,%rdx
  sub    %rdx,%rax
  mov    %rax,-0x8(%rbp)
  mov    -0x8(%rbp),%rdx
  mov    %rdx,%rax
  shl    $0x2,%rax
  add    %rdx,%rax
  add    %rax,%rax
  sub    %rax,%rcx
  mov    %rcx,%rdx
  mov    %rdx,-0x8(%rbp)
  mov    -0x8(%rbp),%rax
  lea    0x30(%rax),%ecx
  mov    -0x50(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x50(%rbp)
  mov    %rax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  mov    %ecx,%edx
  mov    %dl,(%rax)
  addq   $0x1,-0x38(%rbp)
L71:
  mov    -0x38(%rbp),%rax
  cmp    -0x30(%rbp),%rax
  jl     L62
  mov    -0x50(%rbp),%rax
  lea    -0x1(%rax),%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movb   $0x0,(%rax)
  mov    -0x20(%rbp),%rax
  leave
  ret
```

assistant: ```c
char *libc_ldtos(long double n) {
  char *buff = malloc(32);
  *buff = +0;
  char *a2 = buff;
  long long i = 0, j = 0, k = 0;
  long long x = 0, y = 0, t = 0, z = 0, u = 0;
  if (n < 0) {
    a2[j++] = '-';
    n = -n;
  }
  y = x = n;
  if (x == 0) {
    a2[j++] = '0';
  }
  k = j;
  while (x > 0) {
    t = x % 10;
    x /= 10;
    a2[k++] = t + '0';
  }
  i = k--;
  while (k > j) {
    swap(a2[j], a2[k]);
    j++;
    k--;
  }
  j = i;
  n = n - y;
  a2[j++] = '.';
  u = (19 - j);
  if (u < 7) {
    u = 7;
  }
  z = 0;
  while (z < (u)) {
    n = n * 10;
    t = (long long)n % 10;
    a2[j++] = t + '0';
    z++;
  }
  a2[j - 1] = '\0';
  return a2;
}
```