user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<crypto_aead_decrypt>:
  endbr64
  push   %r15
  push   %r14
  mov    %r9,%r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rsi,%rbx
  sub    $0xf8,%rsp
  mov    %rdi,0x18(%rsp)
  mov    0x138(%rsp),%rsi
  lea    0x30(%rsp),%rbp
  mov    %rcx,0x10(%rsp)
  mov    0x140(%rsp),%rdi
  mov    %rbp,%rdx
  mov    %r8,0x20(%rsp)
  mov    %r9,0x28(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0xe8(%rsp)
  xor    %eax,%eax
  call   <morus_initialization@plt>
  cmpq   $0x1f,0x130(%rsp)
  jbe    L89
  mov    $0x20,%r13d
  mov    $0x20,%r12d
  lea    0x60(%rsp),%r15
  sub    %r14d,%r13d
  sub    %r14,%r12
  nopl   (%rax)
L33:
  lea    0x0(%r13,%r14,1),%eax
  mov    %r14,%rdi
  mov    %rbp,%rdx
  mov    %r15,%rsi
  add    $0x20,%r14
  mov    %eax,0xc(%rsp)
  call   <morus_enc_aut_step@plt>
  lea    (%r12,%r14,1),%rax
  cmp    %rax,0x130(%rsp)
  jae    L33
L67:
  mov    0x130(%rsp),%rdx
  and    $0x1f,%edx
  jne    L48
L45:
  mov    0x20(%rsp),%rdi
  sub    $0x10,%rdi
  mov    %rdi,(%rbx)
  cmp    $0x1f,%rdi
  jbe    L82
  mov    0x10(%rsp),%rax
  mov    $0x40,%r15d
  lea    -0x40(%rax),%r14
  mov    0x18(%rsp),%rax
  lea    -0x40(%rax),%r13
L43:
  lea    0x0(%r13,%r15,1),%rdi
  lea    (%r14,%r15,1),%rsi
  mov    %rbp,%rdx
  call   <morus_dec_aut_step@plt>
  mov    (%rbx),%rdi
  mov    %r15,%rax
  lea    -0x20(%r15),%r12d
  add    $0x20,%r15
  cmp    %rax,%rdi
  jae    L43
L20:
  mov    %rdi,%rdx
  and    $0x1f,%edx
  jne    L2
L97:
  mov    0x10(%rsp),%rdx
  mov    0x130(%rsp),%rsi
  mov    %rbp,%rcx
  call   <morus_tag_verification@plt>
  mov    0xe8(%rsp),%rdx
  sub    %fs:0x28,%rdx
  jne    L8
  add    $0xf8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  cs nopw 0x0(%rax,%rax,1)
L48:
  movslq 0xc(%rsp),%r14
  mov    0x28(%rsp),%rdi
  lea    0x60(%rsp),%rsi
  mov    %rbp,%rcx
  add    %r14,%rdi
  call   <morus_enc_aut_partialblock@plt>
  jmp    L45
  nop
L2:
  mov    0x10(%rsp),%rax
  mov    0x18(%rsp),%rdi
  movslq %r12d,%r12
  mov    %rbp,%rcx
  add    %r12,%rdi
  lea    (%rax,%r12,1),%rsi
  call   <morus_dec_aut_partialblock@plt>
  mov    (%rbx),%rdi
  jmp    L97
  nopl   0x0(%rax)
L82:
  xor    %r12d,%r12d
  jmp    L20
L89:
  movl   $0x0,0xc(%rsp)
  jmp    L67
L8:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
int crypto_aead_decrypt(unsigned char *m, unsigned long long *mlen, unsigned char *nsec, const unsigned char *c, unsigned long long clen, const unsigned char *ad, unsigned long long adlen, const unsigned char *npub, const unsigned char *k) {
  uint64_t i, j;
  uint8_t plaintextblock[32], ciphertextblock[32];
  uint8_t tag[16];
  uint8_t check = 0;
  __m128i morus_state[5][2];
  morus_initialization(k, npub, morus_state);
  for (i = 0; (i + 32) <= adlen; i += 32) {
    morus_enc_aut_step(ad + i, ciphertextblock, morus_state);
  }
  if ((adlen & 0x1f) != 0) {
    morus_enc_aut_partialblock(ad + i, ciphertextblock, adlen & 0x1f, morus_state);
  }
  *mlen = clen - 16;
  for (i = 0; (i + 32) <= *mlen; i += 32) {
    morus_dec_aut_step(m + i, c + i, morus_state);
  }
  if ((*mlen & 0x1f) != 0) {
    morus_dec_aut_partialblock(m + i, c + i, *mlen & 0x1f, morus_state);
  }
  return morus_tag_verification(*mlen, adlen, c, morus_state);
}
```