user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<muldivmod>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    %rdi,%rbx
  mov    %edx,%r12d
  mov    %ecx,0xc(%rsp)
  mov    %r8d,%ebp
  mov    %r9,(%rsp)
  mov    %edx,%r14d
  and    $0xf0,%r14d
  mov    %edx,%r15d
  and    $0x7,%r15d
  cmp    $0x30,%r14d
  sete   %r13b
  cmp    $0x90,%r14d
  sete   %dl
  or     %dl,%r13b
  jne    L19
L52:
  test   %ebp,%ebp
  jne    L168
L174:
  mov    $0x2,%esi
  mov    %rbx,%rdi
  call   <emit_push@plt>
  jmp    L107
L19:
  mov    %rsi,%rdx
  mov    $0x1,%esi
  call   <emit_load_imm@plt>
  cmp    $0x7,%r15d
  je     L45
  mov    0xc(%rsp),%ecx
  mov    %ecx,%edx
  mov    $0x85,%esi
  mov    %rbx,%rdi
  call   <emit_alu32@plt>
L125:
  mov    $0xfffffffe,%edx
  mov    $0x84,%esi
  mov    %rbx,%rdi
  call   <emit_jcc@plt>
  jmp    L52
L45:
  mov    0xc(%rsp),%ecx
  mov    %ecx,%edx
  mov    $0x85,%esi
  mov    %rbx,%rdi
  call   <emit_alu64@plt>
  jmp    L125
L168:
  mov    $0x0,%esi
  mov    %rbx,%rdi
  call   <emit_push@plt>
  cmp    $0x2,%ebp
  jne    L174
L107:
  mov    (%rsp),%rdx
  test   %rdx,%rdx
  je     L129
  mov    $0x1,%esi
  mov    %rbx,%rdi
  call   <emit_load_imm@plt>
L103:
  mov    $0x0,%edx
  mov    %ebp,%esi
  mov    %rbx,%rdi
  call   <emit_mov@plt>
  test   %r13b,%r13b
  jne    L189
L37:
  cmp    $0x7,%r15d
  je     L205
L212:
  cmp    $0x20,%r14d
  je     L206
  mov    $0x1,%ecx
  mov    $0x6,%edx
  mov    $0xf7,%esi
  mov    %rbx,%rdi
  call   <emit_alu32@plt>
  cmp    $0x2,%ebp
  je     L140
  cmp    $0x90,%r14d
  je     L195
L31:
  mov    $0x2,%esi
  mov    %rbx,%rdi
  call   <emit_pop@plt>
  test   %ebp,%ebp
  jne    L140
L149:
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L129:
  mov    $0x1,%edx
  mov    0xc(%rsp),%esi
  mov    %rbx,%rdi
  call   <emit_mov@plt>
  jmp    L103
L189:
  mov    $0x2,%ecx
  mov    $0x2,%edx
  mov    $0x31,%esi
  mov    %rbx,%rdi
  call   <emit_alu32@plt>
  jmp    L37
L205:
  mov    $0x0,%r8d
  mov    $0x0,%ecx
  mov    $0x0,%edx
  mov    $0x1,%esi
  mov    %rbx,%rdi
  call   <emit_rex@plt>
  jmp    L212
L195:
  mov    %ebp,%edx
  mov    $0x2,%esi
  mov    %rbx,%rdi
  call   <emit_mov@plt>
  jmp    L31
L187:
  mov    %ebp,%edx
  mov    $0x0,%esi
  mov    %rbx,%rdi
  call   <emit_mov@plt>
  jmp    L23
L206:
  mov    $0x1,%ecx
  mov    $0x4,%edx
  mov    $0xf7,%esi
  mov    %rbx,%rdi
  call   <emit_alu32@plt>
  cmp    $0x2,%ebp
  jne    L31
L140:
  and    $0xe0,%r12d
  cmp    $0x20,%r12d
  je     L187
L23:
  mov    $0x0,%esi
  mov    %rbx,%rdi
  call   <emit_pop@plt>
  jmp    L149
```

assistant: ```c
void muldivmod(struct jit_state *state, uint16_t pc, uint8_t opcode, int src, int dst, int32_t imm) {
  bool mul = (opcode & 0xf0) == ((0x04 | 0x00 | 0x20) & 0xf0);
  bool div = (opcode & 0xf0) == ((0x04 | 0x00 | 0x30) & 0xf0);
  bool mod = (opcode & 0xf0) == ((0x04 | 0x00 | 0x90) & 0xf0);
  bool is64 = (opcode & 0x07) == 0x07;
  if (div || mod) {
    emit_load_imm(state, 1, pc);
    if (is64) {
      emit_alu64(state, 0x85, src, src);
    } else {
      emit_alu32(state, 0x85, src, src);
    }
    emit_jcc(state, 0x84, -2);
  }
  if (dst != 0) {
    emit_push(state, 0);
  }
  if (dst != 2) {
    emit_push(state, 2);
  }
  if (imm) {
    emit_load_imm(state, 1, imm);
  } else {
    emit_mov(state, src, 1);
  }
  emit_mov(state, dst, 0);
  if (div || mod) {
    emit_alu32(state, 0x31, 2, 2);
  }
  if (is64) {
    emit_rex(state, 1, 0, 0, 0);
  }
  emit_alu32(state, 0xf7, mul ? 4 : 6, 1);
  if (dst != 2) {
    if (mod) {
      emit_mov(state, 2, dst);
    }
    emit_pop(state, 2);
  }
  if (dst != 0) {
    if (div || mul) {
      emit_mov(state, 0, dst);
    }
    emit_pop(state, 0);
  }
}
```