user: 请从给定的汇编指令推导出C源代码：

```asm
<mergeSort>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x30,%rsp
  mov    %rdi,-0x18(%rbp)
  mov    %rsi,-0x20(%rbp)
  mov    %rdx,-0x28(%rbp)
  mov    %rcx,-0x30(%rbp)
  cmpq   $0x1,-0x20(%rbp)
  jbe    L11
  mov    -0x20(%rbp),%rax
  shr    %rax
  mov    %rax,%rsi
  mov    -0x30(%rbp),%rcx
  mov    -0x28(%rbp),%rdx
  mov    -0x18(%rbp),%rax
  mov    %rax,%rdi
  call   <mergeSort>
  mov    -0x20(%rbp),%rax
  shr    %rax
  mov    %rax,%rdx
  mov    -0x20(%rbp),%rax
  sub    %rdx,%rax
  mov    %rax,%rsi
  mov    -0x20(%rbp),%rax
  shr    %rax
  imul   -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x18(%rbp),%rax
  lea    (%rdx,%rax,1),%rdi
  mov    -0x30(%rbp),%rdx
  mov    -0x28(%rbp),%rax
  mov    %rdx,%rcx
  mov    %rax,%rdx
  call   <mergeSort>
  mov    -0x28(%rbp),%rdx
  mov    -0x20(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <calloc@plt>
  mov    %rax,-0x8(%rbp)
  cmpq   $0x0,-0x8(%rbp)
  jne    L47
  mov    D6(%rip),%rax
  mov    (%rax),%eax
  mov    %eax,%edi
  call   <exit@plt>
L47:
  movl   $0x0,-0xc(%rbp)
  mov    -0xc(%rbp),%eax
  mov    %eax,-0x10(%rbp)
  jmp    L53
L67:
  mov    -0x20(%rbp),%rax
  shr    %rax
  mov    %rax,%rdx
  mov    -0xc(%rbp),%eax
  cltq
  add    %rdx,%rax
  imul   -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x18(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x10(%rbp),%eax
  cltq
  imul   -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x18(%rbp),%rax
  add    %rax,%rdx
  mov    -0x30(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rdx,%rdi
  call   *%rax
  test   %eax,%eax
  jle    L71
  mov    -0x20(%rbp),%rax
  shr    %rax
  mov    %rax,%rdx
  mov    -0xc(%rbp),%eax
  cltq
  add    %rdx,%rax
  imul   -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x18(%rbp),%rax
  lea    (%rdx,%rax,1),%rsi
  mov    -0x10(%rbp),%edx
  mov    -0xc(%rbp),%eax
  add    %edx,%eax
  cltq
  imul   -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x8(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    %rcx,%rdi
  call   <memcpy@plt>
  addl   $0x1,-0xc(%rbp)
  jmp    L53
L71:
  mov    -0x10(%rbp),%eax
  cltq
  imul   -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x18(%rbp),%rax
  lea    (%rdx,%rax,1),%rsi
  mov    -0x10(%rbp),%edx
  mov    -0xc(%rbp),%eax
  add    %edx,%eax
  cltq
  imul   -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x8(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    %rcx,%rdi
  call   <memcpy@plt>
  addl   $0x1,-0x10(%rbp)
L53:
  mov    -0x10(%rbp),%eax
  cltq
  mov    -0x20(%rbp),%rdx
  shr    %rdx
  cmp    %rdx,%rax
  jae    L27
  mov    -0xc(%rbp),%eax
  cltq
  mov    -0x20(%rbp),%rdx
  mov    %rdx,%rcx
  shr    %rcx
  mov    -0x20(%rbp),%rdx
  sub    %rcx,%rdx
  cmp    %rdx,%rax
  jb     L67
L27:
  mov    -0x10(%rbp),%eax
  cltq
  mov    -0x20(%rbp),%rdx
  shr    %rdx
  cmp    %rdx,%rax
  jne    L85
  mov    -0x20(%rbp),%rax
  shr    %rax
  mov    %rax,%rcx
  mov    -0x20(%rbp),%rax
  sub    %rcx,%rax
  mov    %rax,%rdx
  mov    -0xc(%rbp),%eax
  movslq %eax,%rcx
  mov    %rdx,%rax
  sub    %rcx,%rax
  imul   -0x28(%rbp),%rax
  mov    -0x20(%rbp),%rdx
  mov    %rdx,%rcx
  shr    %rcx
  mov    -0xc(%rbp),%edx
  movslq %edx,%rdx
  add    %rcx,%rdx
  mov    %rdx,%rcx
  imul   -0x28(%rbp),%rcx
  mov    -0x18(%rbp),%rdx
  lea    (%rcx,%rdx,1),%rsi
  mov    -0x10(%rbp),%ecx
  mov    -0xc(%rbp),%edx
  add    %ecx,%edx
  movslq %edx,%rdx
  mov    %rdx,%rcx
  imul   -0x28(%rbp),%rcx
  mov    -0x8(%rbp),%rdx
  add    %rdx,%rcx
  mov    %rax,%rdx
  mov    %rcx,%rdi
  call   <memcpy@plt>
  jmp    L34
L85:
  mov    -0x20(%rbp),%rax
  shr    %rax
  mov    %rax,%rdx
  mov    -0x10(%rbp),%eax
  movslq %eax,%rcx
  mov    %rdx,%rax
  sub    %rcx,%rax
  imul   -0x28(%rbp),%rax
  mov    -0x10(%rbp),%edx
  movslq %edx,%rdx
  mov    %rdx,%rcx
  imul   -0x28(%rbp),%rcx
  mov    -0x18(%rbp),%rdx
  lea    (%rcx,%rdx,1),%rsi
  mov    -0x10(%rbp),%ecx
  mov    -0xc(%rbp),%edx
  add    %ecx,%edx
  movslq %edx,%rdx
  mov    %rdx,%rcx
  imul   -0x28(%rbp),%rcx
  mov    -0x8(%rbp),%rdx
  add    %rdx,%rcx
  mov    %rax,%rdx
  mov    %rcx,%rdi
  call   <memcpy@plt>
L34:
  mov    -0x20(%rbp),%rax
  imul   -0x28(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x8(%rbp),%rcx
  mov    -0x18(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <memcpy@plt>
  mov    -0x8(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  jmp    L54
L11:
  nop
L54:
  leave
  ret
```

assistant: ```c
void *mergeSort(void *base, size_t nmeb, size_t size, int (*compar)(const void *, const void *)) {
  if (nmeb < 2)
    return;
  mergeSort(base, nmeb / 2, size, compar);
  mergeSort(base + (nmeb / 2) * size, nmeb - nmeb / 2, size, compar);
  int i, j;
  void *hold;
  hold = calloc(nmeb, size);
  if (hold == NULL) {
    exit(EXIT_FAILURE);
  }
  i = j = 0;
  while (i < nmeb / 2 && j < nmeb - nmeb / 2) {
    if (compar(base + i * size, base + (nmeb / 2 + j) * size) > 0) {
      memcpy(hold + (i + j) * size, base + (nmeb / 2 + j) * size, size);
      ++j;
    } else {
      memcpy(hold + (i + j) * size, base + i * size, size);
      ++i;
    }
  }
  if (i == nmeb / 2) {
    memcpy(hold + (i + j) * size, base + (nmeb / 2 + j) * size, (nmeb - nmeb / 2 - j) * size);
  } else {
    memcpy(hold + (i + j) * size, base + i * size, (nmeb / 2 - i) * size);
  }
  memcpy(base, hold, nmeb * size);
  free(hold);
}
```