user: 请从给定的汇编指令推导出C源代码：

```asm
<main>:
  endbr64
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x20,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x18(%rsp)
  xor    %eax,%eax
  mov    $0x800000,%edi
  call   <malloc@plt>
  mov    %rax,%rbx
  test   %rax,%rax
  je     L32
L105:
  mov    $0x0,%eax
  call   <skiplist_new@plt>
  mov    %rax,%r13
  test   %rax,%rax
  je     L92
L14:
  lea    D66(%rip),%rdi
  call   <puts@plt>
  mov    $0x200000,%esi
  lea    D63(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  mov    $0x0,%edi
  call   <time@plt>
  mov    %eax,%edi
  call   <srandom@plt>
  lea    0x8(%rsp),%rdi
  mov    $0x0,%esi
  call   <gettimeofday@plt>
  mov    %rbx,%rbp
  lea    0x800000(%rbx),%r14
  mov    %rbx,%r12
L39:
  mov    $0x0,%eax
  call   <random@plt>
  mov    %eax,%esi
  mov    %eax,(%r12)
  mov    %eax,%edx
  mov    %r13,%rdi
  call   <skiplist_insert@plt>
  add    $0x4,%r12
  cmp    %r14,%r12
  jne    L39
  lea    0x10(%rsp),%rdi
  mov    $0x0,%esi
  call   <gettimeofday@plt>
  mov    0x10(%rsp),%esi
  sub    0x8(%rsp),%esi
  imul   $0x3e8,%esi,%esi
  mov    0x14(%rsp),%edx
  sub    0xc(%rsp),%edx
  movslq %edx,%rax
  imul   $0x10624dd3,%rax,%rax
  sar    $0x26,%rax
  sar    $0x1f,%edx
  sub    %edx,%eax
  add    %eax,%esi
  lea    D22(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    D50(%rip),%rdi
  call   <puts@plt>
  lea    0x8(%rsp),%rdi
  mov    $0x0,%esi
  call   <gettimeofday@plt>
  lea    D46(%rip),%r12
  jmp    L48
L32:
  mov    $0xffffffff,%edi
  call   <exit@plt>
  jmp    L105
L92:
  mov    $0xffffffff,%edi
  call   <exit@plt>
  jmp    L14
L88:
  add    $0x4,%rbx
  cmp    %r14,%rbx
  je     L70
L48:
  mov    (%rbx),%esi
  mov    %r13,%rdi
  call   <skiplist_search@plt>
  test   %rax,%rax
  jne    L88
  mov    (%rbx),%esi
  mov    %r12,%rdi
  call   <printf@plt>
  jmp    L88
L70:
  lea    0x10(%rsp),%rdi
  mov    $0x0,%esi
  call   <gettimeofday@plt>
  mov    0x10(%rsp),%esi
  sub    0x8(%rsp),%esi
  imul   $0x3e8,%esi,%esi
  mov    0x14(%rsp),%edx
  sub    0xc(%rsp),%edx
  movslq %edx,%rax
  imul   $0x10624dd3,%rax,%rax
  sar    $0x26,%rax
  sar    $0x1f,%edx
  sub    %edx,%eax
  add    %eax,%esi
  lea    D0(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    D10(%rip),%rdi
  call   <puts@plt>
  lea    0x8(%rsp),%rdi
  mov    $0x0,%esi
  call   <gettimeofday@plt>
L31:
  mov    0x0(%rbp),%esi
  mov    %r13,%rdi
  call   <skiplist_remove@plt>
  add    $0x4,%rbp
  cmp    %r14,%rbp
  jne    L31
  lea    0x10(%rsp),%rdi
  mov    $0x0,%esi
  call   <gettimeofday@plt>
  mov    0x10(%rsp),%esi
  sub    0x8(%rsp),%esi
  imul   $0x3e8,%esi,%esi
  mov    0x14(%rsp),%edx
  sub    0xc(%rsp),%edx
  movslq %edx,%rax
  imul   $0x10624dd3,%rax,%rax
  sar    $0x26,%rax
  sar    $0x1f,%edx
  sub    %edx,%eax
  add    %eax,%esi
  lea    D22(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    D14(%rip),%rdi
  call   <puts@plt>
  mov    %r13,%rdi
  call   <skiplist_delete@plt>
  mov    0x18(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L53
  mov    $0x0,%eax
  add    $0x20,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L53:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: extract_symbolic_data
arguments: label: D66
data_type: string
name: extract_symbolic_data
arguments: label: D63
data_type: string
name: extract_symbolic_data
arguments: label: D22
data_type: string
name: extract_symbolic_data
arguments: label: D50
data_type: string
name: extract_symbolic_data
arguments: label: D46
data_type: string
name: extract_symbolic_data
arguments: label: D0
data_type: string
name: extract_symbolic_data
arguments: label: D10
data_type: string
name: extract_symbolic_data
arguments: label: D14
data_type: string

tool: D66: Test start!

tool: D63: Add %d nodes...


tool: D22: time span: %ldms


tool: D50: Now search each node...

tool: D46: Not found:0x%08x


tool: D0: time span:% ldms


tool: D10: Now remove all nodes...

tool: D14: End of Test.

assistant: ```c
int main(void) {
  int i;
  struct timeval start, end;
  int *key = malloc(2 * 1024 * 1024 * sizeof(int));
  if (key == NULL) {
    exit(-1);
  }
  struct skiplist *list = skiplist_new();
  if (list == NULL) {
    exit(-1);
  }
  printf("Test start!\n");
  printf("Add %d nodes...\n", 2 * 1024 * 1024);
  srandom(time(NULL));
  gettimeofday(&start, NULL);
  for (i = 0; i < 2 * 1024 * 1024; i++) {
    int value = key[i] = (int)random();
    skiplist_insert(list, key[i], value);
  }
  gettimeofday(&end, NULL);
  printf("time span: %ldms\n", (end.tv_sec - start.tv_sec) * 1000 + (end.tv_usec - start.tv_usec) / 1000);
  printf("Now search each node...\n");
  gettimeofday(&start, NULL);
  for (i = 0; i < 2 * 1024 * 1024; i++) {
    struct skipnode *node = skiplist_search(list, key[i]);
    if (node != NULL) {
    } else {
      printf("Not found:0x%08x\n", key[i]);
    }
  }
  gettimeofday(&end, NULL);
  printf("time span:% ldms\n", (end.tv_sec - start.tv_sec) * 1000 + (end.tv_usec - start.tv_usec) / 1000);
  printf("Now remove all nodes...\n");
  gettimeofday(&start, NULL);
  for (i = 0; i < 2 * 1024 * 1024; i++) {
    skiplist_remove(list, key[i]);
  }
  gettimeofday(&end, NULL);
  printf("time span: %ldms\n", (end.tv_sec - start.tv_sec) * 1000 + (end.tv_usec - start.tv_usec) / 1000);
  printf("End of Test.\n");
  skiplist_delete(list);
  return 0;
}
```