user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<f>:
  endbr64
  lea    -0x1(%rdi),%ecx
  cmp    $0x1,%ecx
  jbe    L645
  cmp    $0x3,%edi
  je     L348
  push   %r15
  mov    %ecx,%esi
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x68,%rsp
  movl   $0x1,0x24(%rsp)
  movl   $0x0,0xc(%rsp)
  cmp    $0x2,%esi
  je     L588
L319:
  cmp    $0x3,%esi
  je     L185
  lea    -0x2(%rsi),%eax
  movl   $0x0,0x10(%rsp)
  mov    %eax,0x20(%rsp)
  movl   $0x1,0x28(%rsp)
  mov    %esi,0x38(%rsp)
  cmp    $0x1,%eax
  je     L212
L285:
  cmp    $0x2,%eax
  je     L561
  mov    %eax,%r10d
  movl   $0x0,0x14(%rsp)
  movl   $0x1,0x2c(%rsp)
  cmp    $0x2,%r10d
  je     L150
L104:
  cmp    $0x3,%r10d
  je     L209
  lea    -0x2(%r10),%r11d
  movl   $0x0,0x18(%rsp)
  movl   $0x1,0x30(%rsp)
  mov    %r10d,0x3c(%rsp)
  cmp    $0x1,%r11d
  je     L342
L310:
  cmp    $0x2,%r11d
  je     L145
  mov    %r11d,%r9d
  movl   $0x0,0x1c(%rsp)
  movl   $0x1,0x34(%rsp)
  mov    %r11d,0x40(%rsp)
  cmp    $0x2,%r9d
  je     L421
L610:
  cmp    $0x3,%r9d
  je     L315
  lea    -0x2(%r9),%r14d
  xor    %r10d,%r10d
  mov    $0x1,%ecx
  cmp    $0x1,%r14d
  je     L280
L183:
  cmp    $0x2,%r14d
  je     L360
  xor    %r15d,%r15d
  mov    $0x1,%ebx
  mov    %r14d,%r13d
  mov    %r14d,%r8d
  mov    %r15d,%esi
  mov    %ebx,%r15d
  cmp    $0x2,%r13d
  je     L403
L50:
  cmp    $0x3,%r13d
  je     L239
  mov    %r15d,%edi
  mov    %r13d,%eax
  lea    -0x2(%r13),%r12d
  mov    %esi,%r15d
  mov    %r10d,%r13d
  xor    %ebx,%ebx
  mov    $0x1,%ebp
  mov    %eax,%r10d
  mov    %edi,%esi
  cmp    $0x1,%r12d
  je     L464
L139:
  cmp    $0x2,%r12d
  je     L222
  mov    %r12d,%edi
  mov    $0x1,%edx
  mov    %ebp,0x44(%rsp)
  xor    %r14d,%r14d
  mov    %r12d,0x48(%rsp)
  mov    %edx,%ebp
  mov    %ebx,%r12d
  mov    %edi,%ebx
L451:
  mov    %ebx,%edi
  mov    %r10d,0x5c(%rsp)
  sub    $0x3,%ebx
  mov    %r8d,0x58(%rsp)
  mov    %r9d,0x54(%rsp)
  mov    %esi,0x50(%rsp)
  mov    %ecx,0x4c(%rsp)
  call   <f>
  mov    0x4c(%rsp),%ecx
  mov    0x50(%rsp),%esi
  imul   %ebp,%eax
  mov    0x54(%rsp),%r9d
  mov    0x58(%rsp),%r8d
  mov    0x5c(%rsp),%r10d
  mov    %eax,%edi
  mov    %ebp,%eax
  neg    %ebp
  cmp    $0x1,%ebx
  lea    (%r14,%rdi,2),%r14d
  jbe    L473
  cmp    $0x2,%ebx
  jne    L451
  mov    %r12d,%ebx
  neg    %eax
  mov    0x44(%rsp),%ebp
  mov    0x48(%rsp),%r12d
  lea    (%r14,%rax,4),%eax
L376:
  imul   %ebp,%eax
  mov    %ebp,%edx
  neg    %edx
  lea    (%rbx,%rax,2),%ebx
  lea    -0x2(%r12),%eax
  cmp    $0x1,%eax
  jbe    L275
  sub    $0x3,%r12d
  cmp    $0x1,%r12d
  je     L297
  mov    %edx,%ebp
  cmp    $0x1,%r12d
  jne    L139
L464:
  mov    $0x2,%eax
  jmp    L376
L275:
  mov    %r10d,%eax
  mov    %esi,%edi
  mov    %r13d,%r10d
  mov    %r15d,%esi
  mov    %eax,%r13d
  mov    %edi,%r15d
  lea    (%rbx,%rdx,2),%eax
  nopl   0x0(%rax)
L412:
  imul   %r15d,%eax
  mov    %r15d,%edx
  sub    $0x3,%r13d
  neg    %edx
  lea    (%rsi,%rax,2),%esi
  cmp    $0x1,%r13d
  jbe    L7
  cmp    $0x2,%r13d
  je     L38
  mov    %edx,%r15d
  cmp    $0x2,%r13d
  jne    L50
L403:
  mov    $0x2,%eax
  jmp    L412
L239:
  mov    %r15d,%ebx
  lea    (%rsi,%r15,8),%eax
  mov    %r8d,%r14d
  neg    %ebx
  lea    (%rax,%rbx,2),%eax
L96:
  imul   %ecx,%eax
  mov    %ecx,%edx
  neg    %edx
  lea    (%r10,%rax,2),%r10d
  lea    -0x2(%r14),%eax
  cmp    $0x1,%eax
  jbe    L235
  sub    $0x3,%r14d
  cmp    $0x1,%r14d
  je     L622
  mov    %edx,%ecx
  cmp    $0x1,%r14d
  jne    L183
L280:
  mov    $0x2,%eax
  jmp    L96
L38:
  mov    %r8d,%r14d
  lea    (%rsi,%rdx,4),%eax
  jmp    L96
L360:
  mov    %ecx,%ebp
  lea    (%r10,%rcx,8),%eax
  neg    %ebp
  lea    (%rax,%rbp,2),%eax
L379:
  mov    0x34(%rsp),%edi
  mov    0x1c(%rsp),%esi
  sub    $0x3,%r9d
  imul   %edi,%eax
  mov    %edi,%edx
  neg    %edx
  lea    (%rsi,%rax,2),%eax
  mov    %eax,0x1c(%rsp)
  cmp    $0x1,%r9d
  jbe    L102
  cmp    $0x2,%r9d
  je     L99
  mov    %edx,0x34(%rsp)
  cmp    $0x2,%r9d
  jne    L610
L421:
  mov    $0x2,%eax
  jmp    L379
L622:
  lea    (%r10,%rdx,4),%eax
  jmp    L379
L7:
  mov    %r8d,%r14d
  lea    (%rsi,%rdx,2),%eax
  jmp    L96
  nopl   0x0(%rax,%rax,1)
L473:
  neg    %eax
  mov    %r12d,%ebx
  mov    0x44(%rsp),%ebp
  mov    0x48(%rsp),%r12d
  lea    (%r14,%rax,2),%eax
  jmp    L376
L99:
  mov    0x40(%rsp),%r11d
  lea    (%rax,%rdx,4),%eax
L326:
  mov    0x30(%rsp),%edi
  imul   %edi,%eax
  mov    %edi,%edx
  mov    0x18(%rsp),%edi
  neg    %edx
  lea    (%rdi,%rax,2),%eax
  mov    %eax,0x18(%rsp)
  lea    -0x2(%r11),%eax
  cmp    $0x1,%eax
  jbe    L483
  sub    $0x3,%r11d
  cmp    $0x1,%r11d
  je     L544
  mov    %edx,0x30(%rsp)
  cmp    $0x1,%r11d
  jne    L310
L342:
  mov    $0x2,%eax
  jmp    L326
L315:
  mov    0x34(%rsp),%eax
  mov    0x1c(%rsp),%ecx
  mov    0x40(%rsp),%r11d
  lea    (%rcx,%rax,8),%edx
  neg    %eax
  lea    (%rdx,%rax,2),%eax
  jmp    L326
L235:
  lea    (%r10,%rdx,2),%eax
  jmp    L379
  nopl   (%rax)
L222:
  mov    %r10d,%eax
  mov    %esi,%edi
  mov    %r13d,%r10d
  mov    %r15d,%esi
  mov    %eax,%r13d
  lea    (%rbx,%rbp,8),%eax
  neg    %ebp
  mov    %edi,%r15d
  lea    (%rax,%rbp,2),%eax
  jmp    L412
  cs nopw 0x0(%rax,%rax,1)
L297:
  mov    %r10d,%eax
  mov    %esi,%edi
  mov    %r13d,%r10d
  mov    %r15d,%esi
  mov    %eax,%r13d
  mov    %edi,%r15d
  lea    (%rbx,%rdx,4),%eax
  jmp    L412
L145:
  mov    0x30(%rsp),%eax
  mov    0x18(%rsp),%edi
  mov    0x3c(%rsp),%r10d
  lea    (%rdi,%rax,8),%edx
  neg    %eax
  lea    (%rdx,%rax,2),%eax
L532:
  mov    0x2c(%rsp),%edi
  mov    0x14(%rsp),%esi
  sub    $0x3,%r10d
  imul   %edi,%eax
  mov    %edi,%edx
  neg    %edx
  lea    (%rsi,%rax,2),%eax
  mov    %eax,0x14(%rsp)
  cmp    $0x1,%r10d
  jbe    L547
  cmp    $0x2,%r10d
  je     L217
  mov    %edx,0x2c(%rsp)
  cmp    $0x2,%r10d
  jne    L104
L150:
  mov    $0x2,%eax
  jmp    L532
L544:
  mov    0x18(%rsp),%eax
  mov    0x3c(%rsp),%r10d
  lea    (%rax,%rdx,4),%eax
  jmp    L532
L102:
  mov    0x40(%rsp),%r11d
  lea    (%rax,%rdx,2),%eax
  jmp    L326
L483:
  mov    0x18(%rsp),%eax
  mov    0x3c(%rsp),%r10d
  lea    (%rax,%rdx,2),%eax
  jmp    L532
L217:
  lea    (%rax,%rdx,4),%eax
L240:
  mov    0x28(%rsp),%edi
  mov    0x10(%rsp),%ebx
  imul   %edi,%eax
  mov    %edi,%edx
  neg    %edx
  lea    (%rbx,%rax,2),%eax
  mov    %eax,0x10(%rsp)
  mov    0x20(%rsp),%eax
  sub    $0x2,%eax
  cmp    $0x1,%eax
  jbe    L301
  subl   $0x3,0x20(%rsp)
  mov    0x20(%rsp),%eax
  cmp    $0x1,%eax
  je     L13
  mov    %edx,0x28(%rsp)
  cmp    $0x1,%eax
  jne    L285
L212:
  mov    $0x2,%eax
  jmp    L240
L547:
  lea    (%rax,%rdx,2),%eax
  jmp    L240
L13:
  mov    0x10(%rsp),%eax
  mov    0x38(%rsp),%esi
  lea    (%rax,%rdx,4),%eax
L363:
  mov    0x24(%rsp),%edi
  sub    $0x3,%esi
  imul   %edi,%eax
  mov    %edi,%edx
  mov    0xc(%rsp),%edi
  neg    %edx
  lea    (%rdi,%rax,2),%eax
  mov    %eax,0xc(%rsp)
  cmp    $0x1,%esi
  jbe    L295
  cmp    $0x2,%esi
  je     L658
  mov    %edx,0x24(%rsp)
  cmp    $0x2,%esi
  jne    L319
L588:
  mov    $0x2,%eax
  jmp    L363
  nopl   0x0(%rax)
L209:
  mov    0x2c(%rsp),%eax
  mov    0x14(%rsp),%esi
  lea    (%rsi,%rax,8),%edx
  neg    %eax
  lea    (%rdx,%rax,2),%eax
  jmp    L240
L561:
  mov    0x28(%rsp),%eax
  mov    0x10(%rsp),%ebx
  mov    0x38(%rsp),%esi
  lea    (%rbx,%rax,8),%edx
  neg    %eax
  lea    (%rdx,%rax,2),%eax
  jmp    L363
L658:
  lea    (%rax,%rdx,4),%eax
L349:
  add    $0x68,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L185:
  mov    0x24(%rsp),%eax
  mov    0xc(%rsp),%ecx
  add    $0x68,%rsp
  pop    %rbx
  pop    %rbp
  lea    (%rcx,%rax,8),%edx
  neg    %eax
  pop    %r12
  pop    %r13
  lea    (%rdx,%rax,2),%eax
  pop    %r14
  pop    %r15
  ret
L645:
  mov    $0x2,%eax
  ret
L348:
  mov    $0x4,%eax
  ret
L301:
  mov    0x10(%rsp),%eax
  mov    0x38(%rsp),%esi
  lea    (%rax,%rdx,2),%eax
  jmp    L363
L295:
  lea    (%rax,%rdx,2),%eax
  jmp    L349
```

assistant: ```c
uint64_t f(uint32_t n) {
  if (n == 1 || n == 2)
    return 2;
  else if (n == 3)
    return 4;
  else
    return (2 * f(n - 1) - f(n - 3));
}
```