user: 请从给定的汇编指令推导出C源代码：

```asm
<f>:
  endbr64
  push   %r15
  lea    -0x1(%rdi),%edx
  mov    %edi,%eax
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x78,%rsp
  mov    %edi,0x4c(%rsp)
  cmp    $0x1,%edx
  jbe    L127
  lea    -0x2(%rdi),%eax
  movl   $0x1,0x20(%rsp)
  mov    %eax,0x50(%rsp)
  mov    %eax,0x4(%rsp)
  movl   $0x0,0x1c(%rsp)
L86:
  mov    0x4(%rsp),%ebx
  lea    0x1(%rbx),%eax
  lea    -0x2(%rbx),%ecx
  lea    -0x1(%rbx),%edx
  cmp    $0x1,%ebx
  jbe    L171
  mov    0x4(%rsp),%eax
  movl   $0x0,0x28(%rsp)
  movl   $0x1,0x24(%rsp)
  mov    %eax,0x3c(%rsp)
L73:
  mov    0x3c(%rsp),%edi
  movl   $0x0,0x44(%rsp)
  mov    %edi,%eax
  cmp    $0x2,%edi
  je     L42
  lea    -0x2(%rdi),%eax
  movl   $0x0,0x30(%rsp)
  mov    %eax,0x44(%rsp)
  mov    %eax,0x18(%rsp)
  movl   $0x1,0x2c(%rsp)
L93:
  mov    0x18(%rsp),%edi
  mov    $0xffffffff,%ecx
  xor    %edx,%edx
  lea    0x1(%rdi),%eax
  cmp    $0x1,%edi
  je     L122
  mov    0x18(%rsp),%eax
  movl   $0x0,0x38(%rsp)
  movl   $0x1,0x34(%rsp)
  mov    %eax,0x40(%rsp)
L149:
  mov    0x40(%rsp),%esi
  movl   $0x0,0x48(%rsp)
  mov    %esi,%eax
  cmp    $0x2,%esi
  je     L61
  lea    -0x2(%rsi),%eax
  xor    %r11d,%r11d
  mov    $0x1,%r10d
  mov    %eax,%ebx
  mov    %eax,0x48(%rsp)
  mov    %r11d,%r9d
  lea    0x1(%rbx),%eax
  cmp    $0x1,%ebx
  je     L174
L87:
  mov    %r10d,0x8(%rsp)
  mov    %ebx,%r12d
  xor    %esi,%esi
  mov    $0x1,%r11d
  mov    %r9d,0xc(%rsp)
  mov    %ebx,0x10(%rsp)
L103:
  mov    %r12d,%eax
  xor    %ecx,%ecx
  cmp    $0x2,%r12d
  je     L165
  mov    %r11d,0x14(%rsp)
  lea    -0x3(%r12),%ecx
  lea    -0x4(%r12),%ebx
  xor    %r9d,%r9d
  mov    %ecx,%r14d
  mov    $0x1,%r10d
  mov    %ebx,%r8d
L231:
  lea    0x1(%r14),%edx
  lea    0x2(%r14),%eax
  cmp    $0x1,%edx
  jbe    L179
  mov    %r14d,%ebp
  xor    %r15d,%r15d
  mov    $0x1,%r13d
  mov    %esi,%ebx
  lea    0x1(%rbp),%eax
  cmp    $0x1,%ebp
  je     L189
L227:
  mov    %ebp,%edx
  xor    %r11d,%r11d
  mov    $0x1,%esi
L201:
  mov    %edx,%edi
  xor    %eax,%eax
  mov    %ecx,0x6c(%rsp)
  mov    %r8d,0x68(%rsp)
  mov    %r11d,0x64(%rsp)
  mov    %esi,0x60(%rsp)
  mov    %r9d,0x5c(%rsp)
  mov    %r10d,0x58(%rsp)
  mov    %edx,0x54(%rsp)
  call   <f>
  mov    0x60(%rsp),%esi
  mov    0x54(%rsp),%edx
  mov    0x64(%rsp),%r11d
  mov    0x58(%rsp),%r10d
  imul   %esi,%eax
  sub    $0x2,%edx
  mov    0x5c(%rsp),%r9d
  mov    0x68(%rsp),%r8d
  lea    0x0(,%rsi,4),%edi
  mov    0x6c(%rsp),%ecx
  sub    %edi,%esi
  cmp    $0x1,%edx
  lea    (%r11,%rax,4),%r11d
  ja     L201
  lea    -0x2(%rbp),%edx
  sub    $0x1,%ebp
  mov    %edx,%edi
  mov    %ebp,%eax
  and    $0xfffffffe,%edi
  sub    %edi,%eax
  imul   %esi,%eax
  add    %r11d,%eax
L95:
  imul   %r13d,%eax
  lea    0x0(,%r13,4),%esi
  sub    %esi,%r13d
  lea    (%r15,%rax,4),%r15d
  cmp    $0x1,%ebp
  jbe    L218
  mov    %edx,%ebp
  lea    0x1(%rbp),%eax
  cmp    $0x1,%ebp
  jne    L227
L189:
  mov    $0xffffffff,%edx
  xor    %ebp,%ebp
  jmp    L95
  cs nopw 0x0(%rax,%rax,1)
L218:
  mov    %r8d,%edx
  mov    %r14d,%eax
  mov    %ebx,%esi
  and    $0xfffffffe,%edx
  sub    %edx,%eax
  imul   %r13d,%eax
  add    %r15d,%eax
L179:
  imul   %r10d,%eax
  lea    0x0(,%r10,4),%edx
  sub    $0x2,%r8d
  sub    %edx,%r10d
  lea    (%r9,%rax,4),%r9d
  lea    -0x2(%r14),%eax
  cmp    $0x1,%r14d
  jbe    L213
  mov    %eax,%r14d
  jmp    L231
  nopl   (%rax)
L213:
  and    $0xfffffffe,%ecx
  mov    0x14(%rsp),%r11d
  mov    %ecx,%edx
  lea    -0x2(%r12),%ecx
  mov    %ecx,%eax
  sub    %edx,%eax
  imul   %r10d,%eax
  add    %r9d,%eax
L165:
  imul   %r11d,%eax
  lea    0x0(,%r11,4),%edx
  mov    %ecx,%r12d
  sub    %edx,%r11d
  lea    (%rsi,%rax,4),%esi
  cmp    $0x1,%ecx
  ja     L103
  mov    0x10(%rsp),%ebx
  mov    0x8(%rsp),%r10d
  mov    0xc(%rsp),%r9d
  lea    -0x2(%rbx),%edx
  sub    $0x1,%ebx
  mov    %edx,%ecx
  mov    %ebx,%eax
  and    $0xfffffffe,%ecx
  sub    %ecx,%eax
  imul   %r11d,%eax
  add    %esi,%eax
L34:
  imul   %r10d,%eax
  lea    0x0(,%r10,4),%ecx
  sub    %ecx,%r10d
  lea    (%r9,%rax,4),%r9d
  cmp    $0x1,%ebx
  jbe    L196
  mov    %edx,%ebx
  lea    0x1(%rbx),%eax
  cmp    $0x1,%ebx
  jne    L87
L174:
  mov    $0xffffffff,%edx
  xor    %ebx,%ebx
  jmp    L34
L196:
  mov    0x40(%rsp),%edx
  mov    0x48(%rsp),%eax
  sub    $0x3,%edx
  and    $0xfffffffe,%edx
  sub    %edx,%eax
  imul   %r10d,%eax
  add    %r9d,%eax
L61:
  mov    0x34(%rsp),%edi
  mov    0x38(%rsp),%ebx
  imul   %edi,%eax
  lea    0x0(,%rdi,4),%edx
  sub    %edx,%edi
  mov    %edi,0x34(%rsp)
  lea    (%rbx,%rax,4),%eax
  mov    %eax,0x38(%rsp)
  mov    0x48(%rsp),%eax
  mov    %eax,0x40(%rsp)
  cmp    $0x1,%eax
  ja     L149
  mov    0x18(%rsp),%eax
  lea    -0x2(%rax),%ecx
  lea    -0x1(%rax),%edx
  mov    %ecx,%esi
  mov    %edx,%eax
  and    $0xfffffffe,%esi
  sub    %esi,%eax
  imul   %edi,%eax
  add    0x38(%rsp),%eax
L122:
  mov    0x2c(%rsp),%edi
  imul   %edi,%eax
  lea    0x0(,%rdi,4),%esi
  sub    %esi,%edi
  mov    %edi,0x2c(%rsp)
  mov    0x30(%rsp),%edi
  lea    (%rdi,%rax,4),%eax
  mov    %eax,0x30(%rsp)
  cmp    $0x1,%edx
  jbe    L136
  mov    %ecx,0x18(%rsp)
  jmp    L93
L136:
  mov    0x3c(%rsp),%edx
  mov    0x44(%rsp),%eax
  sub    $0x3,%edx
  and    $0xfffffffe,%edx
  sub    %edx,%eax
  imul   0x2c(%rsp),%eax
  add    0x30(%rsp),%eax
L42:
  mov    0x24(%rsp),%edi
  mov    0x28(%rsp),%esi
  imul   %edi,%eax
  lea    0x0(,%rdi,4),%edx
  sub    %edx,%edi
  mov    %edi,0x24(%rsp)
  lea    (%rsi,%rax,4),%eax
  mov    %eax,0x28(%rsp)
  mov    0x44(%rsp),%eax
  mov    %eax,0x3c(%rsp)
  cmp    $0x1,%eax
  ja     L73
  mov    0x4(%rsp),%eax
  lea    -0x2(%rax),%ecx
  lea    -0x1(%rax),%edx
  mov    %ecx,%esi
  mov    %edx,%eax
  and    $0xfffffffe,%esi
  sub    %esi,%eax
  imul   %edi,%eax
  add    0x28(%rsp),%eax
L171:
  mov    0x20(%rsp),%ebx
  imul   %ebx,%eax
  lea    0x0(,%rbx,4),%esi
  sub    %esi,%ebx
  mov    %ebx,0x20(%rsp)
  mov    0x1c(%rsp),%ebx
  lea    (%rbx,%rax,4),%eax
  mov    %eax,0x1c(%rsp)
  cmp    $0x1,%edx
  jbe    L193
  mov    %ecx,0x4(%rsp)
  jmp    L86
L193:
  mov    0x4c(%rsp),%edx
  mov    0x50(%rsp),%eax
  sub    $0x3,%edx
  and    $0xfffffffe,%edx
  sub    %edx,%eax
  imul   0x20(%rsp),%eax
  add    0x1c(%rsp),%eax
L127:
  add    $0x78,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
int f(n) {
  switch (n) {
  case 1:
  case 2:
    return n;
  default:
    return 4 * f(n - 1) - 3 * f(n - 2);
  }
}
```