user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<crypto_aead_decrypt>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  mov    %r9,%r13
  push   %r12
  push   %rbp
  mov    %rsi,%rbp
  push   %rbx
  mov    %r8,%rbx
  sub    $0x68,%rsp
  mov    %rdi,0x8(%rsp)
  lea    0x20(%rsp),%r15
  mov    0xa8(%rsp),%rsi
  mov    %rcx,(%rsp)
  mov    0xb0(%rsp),%rdi
  mov    %r15,%rdx
  mov    %r8,0x10(%rsp)
  mov    0xa0(%rsp),%r12
  mov    %r9,0x18(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x58(%rsp)
  xor    %eax,%eax
  call   <morus_initialization@plt>
  cmp    $0xf,%rbx
  jbe    L1
  cmp    $0xf,%r12
  jbe    L88
  mov    $0x10,%ebx
  lea    0x40(%rsp),%r14
  sub    $0x10,%r13
  nopl   (%rax)
L114:
  lea    0x0(%r13,%rbx,1),%rdi
  mov    %r15,%rdx
  mov    %r14,%rsi
  call   <morus_enc_aut_step@plt>
  mov    %rbx,%rax
  add    $0x10,%rbx
  cmp    %rbx,%r12
  jae    L114
L121:
  mov    %r12,%rdx
  and    $0xf,%edx
  jne    L50
L85:
  mov    0x10(%rsp),%rdx
  sub    $0x10,%rdx
  mov    %rdx,0x0(%rbp)
  cmp    $0xf,%rdx
  jbe    L0
  mov    (%rsp),%rax
  mov    $0x10,%ebx
  lea    -0x10(%rax),%r14
  mov    0x8(%rsp),%rax
  lea    -0x10(%rax),%r13
  nopl   (%rax)
L84:
  lea    (%r14,%rbx,1),%rsi
  lea    0x0(%r13,%rbx,1),%rdi
  mov    %r15,%rdx
  call   <morus_dec_aut_step@plt>
  mov    0x0(%rbp),%rdx
  mov    %rbx,%rax
  add    $0x10,%rbx
  cmp    %rbx,%rdx
  jae    L84
L20:
  and    $0xf,%edx
  jne    L53
L36:
  mov    (%rsp),%rdx
  mov    0x0(%rbp),%rdi
  mov    %r15,%rcx
  mov    %r12,%rsi
  call   <morus_tag_verification@plt>
L77:
  mov    0x58(%rsp),%rdx
  sub    %fs:0x28,%rdx
  jne    L115
  add    $0x68,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax,%rax,1)
L50:
  mov    0x18(%rsp),%rdi
  lea    0x40(%rsp),%rsi
  mov    %r15,%rcx
  add    %rax,%rdi
  call   <morus_enc_aut_partialblock@plt>
  jmp    L85
  nopw   0x0(%rax,%rax,1)
L53:
  mov    (%rsp),%rcx
  mov    0x8(%rsp),%rdi
  lea    (%rcx,%rax,1),%rsi
  add    %rax,%rdi
  mov    %r15,%rcx
  call   <morus_dec_aut_partialblock@plt>
  jmp    L36
  nopw   0x0(%rax,%rax,1)
L88:
  xor    %eax,%eax
  jmp    L121
  nopw   0x0(%rax,%rax,1)
L0:
  xor    %eax,%eax
  jmp    L20
L1:
  mov    $0xffffffff,%eax
  jmp    L77
L115:
  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) {
  unsigned long i, j;
  unsigned char plaintextblock[16], ciphertextblock[16];
  unsigned char tag[16];
  __m128i morus_state[5];
  morus_initialization(k, npub, morus_state);
  if (clen < 16)
    return -1;
  for (i = 0; (i + 16) <= adlen; i += 16) {
    morus_enc_aut_step(ad + i, ciphertextblock, morus_state);
  }
  if ((adlen & 0xf) != 0) {
    morus_enc_aut_partialblock(ad + i, ciphertextblock, adlen & 0xf, morus_state);
  }
  *mlen = clen - 16;
  for (i = 0; (i + 16) <= *mlen; i += 16) {
    morus_dec_aut_step(m + i, c + i, morus_state);
  }
  if ((*mlen & 0xf) != 0) {
    morus_dec_aut_partialblock(m + i, c + i, *mlen & 0xf, morus_state);
  }
  return morus_tag_verification(*mlen, adlen, c, morus_state);
}
```