user: Converte this assembly snippet into its equivalent C code:

```asm
<main>:
  endbr64
  push   %rbp
  mov    $0x20,%edx
  xor    %esi,%esi
  sub    $0x30,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x28(%rsp)
  xor    %eax,%eax
  mov    %rsp,%rbp
  mov    %rbp,%rdi
  call   <memset@plt>
  mov    $0x1,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xffff,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x2,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xffff,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x4,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xffff,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x8,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xffff,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x10,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xffff,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xffff,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%edx
  mov    $0xff,%esi
  mov    %rbp,%rdi
  call   <memset@plt>
  mov    $0x1,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xff00,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x2,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  test   %eax,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x4,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  test   %eax,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x8,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  test   %eax,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x10,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  test   %eax,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  test   %eax,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%edx
  mov    $0x1,%esi
  mov    %rbp,%rdi
  call   <memset@plt>
  mov    $0x1,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xfffe,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x2,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xfefe,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x4,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xfdfd,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x8,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xfbfb,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x10,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xf7f7,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xefef,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%edx
  mov    $0x11,%esi
  mov    %rbp,%rdi
  call   <memset@plt>
  mov    $0x1,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xffee,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x2,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xeeee,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x4,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xdddd,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x8,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xbbbb,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x10,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0x7777,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xeeee,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%edx
  mov    $0xaa,%esi
  mov    %rbp,%rdi
  call   <memset@plt>
  mov    $0x1,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xff55,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x2,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0x5555,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x4,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xaaaa,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x8,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0x5555,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x10,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xaaaa,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0x5555,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x20,%edx
  mov    $0x93,%esi
  mov    %rbp,%rdi
  call   <memset@plt>
  mov    $0x1,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xff6c,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x2,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0x6c6c,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x4,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xd8d8,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x8,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xb1b1,%eax
  sete   %dil
  call   <assert@plt>
  mov    $0x10,%esi
  mov    %rbp,%rdi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0x6363,%eax
  sete   %dil
  call   <assert@plt>
  mov    %rbp,%rdi
  mov    $0x20,%esi
  call   <checksum@plt>
  xor    %edi,%edi
  cmp    $0xc6c6,%eax
  sete   %dil
  call   <assert@plt>
  mov    0x28(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L1
  add    $0x30,%rsp
  xor    %eax,%eax
  pop    %rbp
  ret
L1:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
int main(void) {
  char buffer[32];
  memset(buffer, 0, 32);
  assert(checksum((uint16_t *)buffer, 1) == 0xffff);
  assert(checksum((uint16_t *)buffer, 2) == 0xffff);
  assert(checksum((uint16_t *)buffer, 4) == 0xffff);
  assert(checksum((uint16_t *)buffer, 8) == 0xffff);
  assert(checksum((uint16_t *)buffer, 16) == 0xffff);
  assert(checksum((uint16_t *)buffer, 32) == 0xffff);
  memset(buffer, 0xff, 32);
  assert(checksum((uint16_t *)buffer, 1) == 0xff00);
  assert(checksum((uint16_t *)buffer, 2) == 0x0000);
  assert(checksum((uint16_t *)buffer, 4) == 0x0000);
  assert(checksum((uint16_t *)buffer, 8) == 0x0000);
  assert(checksum((uint16_t *)buffer, 16) == 0x0000);
  assert(checksum((uint16_t *)buffer, 32) == 0x0000);
  memset(buffer, 0x01, 32);
  assert(checksum((uint16_t *)buffer, 1) == 0xfffe);
  assert(checksum((uint16_t *)buffer, 2) == 0xfefe);
  assert(checksum((uint16_t *)buffer, 4) == 0xfdfd);
  assert(checksum((uint16_t *)buffer, 8) == 0xfbfb);
  assert(checksum((uint16_t *)buffer, 16) == 0xf7f7);
  assert(checksum((uint16_t *)buffer, 32) == 0xefef);
  memset(buffer, 0x11, 32);
  assert(checksum((uint16_t *)buffer, 1) == 0xffee);
  assert(checksum((uint16_t *)buffer, 2) == 0xeeee);
  assert(checksum((uint16_t *)buffer, 4) == 0xdddd);
  assert(checksum((uint16_t *)buffer, 8) == 0xbbbb);
  assert(checksum((uint16_t *)buffer, 16) == 0x7777);
  assert(checksum((uint16_t *)buffer, 32) == 0xeeee);
  memset(buffer, 0xaa, 32);
  assert(checksum((uint16_t *)buffer, 1) == 0xff55);
  assert(checksum((uint16_t *)buffer, 2) == 0x5555);
  assert(checksum((uint16_t *)buffer, 4) == 0xaaaa);
  assert(checksum((uint16_t *)buffer, 8) == 0x5555);
  assert(checksum((uint16_t *)buffer, 16) == 0xaaaa);
  assert(checksum((uint16_t *)buffer, 32) == 0x5555);
  memset(buffer, 0x93, 32);
  assert(checksum((uint16_t *)buffer, 1) == 0xff6c);
  assert(checksum((uint16_t *)buffer, 2) == 0x6c6c);
  assert(checksum((uint16_t *)buffer, 4) == 0xd8d8);
  assert(checksum((uint16_t *)buffer, 8) == 0xb1b1);
  assert(checksum((uint16_t *)buffer, 16) == 0x6363);
  assert(checksum((uint16_t *)buffer, 32) == 0xc6c6);
  return 0;
}
```