user: 请将以下的汇编代码转换成C语言代码:

```asm
<regexp_infx2postfx>:
  endbr64
  push   %rbx
  sub    $0x650,%rsp
  mov    %rdi,%rbx
  mov    %fs:0x28,%rax
  mov    %rax,0x648(%rsp)
  xor    %eax,%eax
  call   <strlen@plt>
  mov    $0x0,%ecx
  cmp    $0xfff,%eax
  jle    L345
L115:
  mov    0x648(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L371
  mov    %rcx,%rax
  add    $0x650,%rsp
  pop    %rbx
  ret
L345:
  movzbl (%rbx),%ecx
  test   %cl,%cl
  je     L320
  mov    %rsp,%rsi
  lea    D4(%rip),%rax
  mov    $0x0,%edx
  mov    $0x0,%edi
  lea    0x640(%rsp),%r9
  mov    %rsp,%r10
  jmp    L71
L171:
  cmp    $0x3f,%cl
  je     L412
  cmp    $0x7c,%cl
  jne    L381
  test   %rdx,%rdx
  je     L239
  sub    $0x1,%rdx
  je     L247
  add    %rax,%rdx
L59:
  add    $0x1,%rax
  movb   $0x10,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L59
L318:
  add    $0x1,%rdi
  mov    %rdx,%rax
  mov    $0x0,%edx
  jmp    L340
L51:
  cmp    $0x1,%rdx
  jbe    L339
  sub    $0x1,%rdx
  movb   $0x10,(%rax)
  lea    0x1(%rax),%rax
L339:
  cmp    %r9,%rsi
  jae    L110
  mov    %rdi,(%rsi)
  mov    %rdx,0x8(%rsi)
  add    $0x10,%rsi
  mov    $0x0,%edx
  mov    $0x0,%edi
  jmp    L340
L63:
  mov    %rax,%rdx
  jmp    L303
L81:
  mov    %rdx,%rax
  jmp    L167
L247:
  mov    %rax,%rdx
  jmp    L318
L412:
  test   %rdx,%rdx
  je     L347
  mov    %cl,(%rax)
  lea    0x1(%rax),%rax
  jmp    L340
L381:
  mov    %rax,%rcx
  cmp    $0x1,%rdx
  jbe    L11
  sub    $0x1,%rdx
  lea    0x1(%rax),%rcx
  movb   $0x10,(%rax)
L11:
  lea    0x1(%rcx),%rax
  movzbl (%rbx),%r8d
  mov    %r8b,(%rcx)
  add    $0x1,%rdx
L340:
  add    $0x1,%rbx
  movzbl (%rbx),%ecx
  test   %cl,%cl
  je     L10
L71:
  cmp    $0x2b,%cl
  jg     L171
  cmp    $0x29,%cl
  jg     L412
  cmp    $0x28,%cl
  je     L51
  cmp    $0x29,%cl
  jne    L381
  test   %rdx,%rdx
  je     L284
  cmp    %r10,%rsi
  je     L284
  sub    $0x1,%rdx
  je     L63
  add    %rax,%rdx
L272:
  add    $0x1,%rax
  movb   $0x10,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L272
L303:
  test   %rdi,%rdi
  je     L81
  lea    (%rdx,%rdi,1),%rax
L170:
  add    $0x1,%rdx
  movb   $0x7c,-0x1(%rdx)
  cmp    %rax,%rdx
  jne    L170
L167:
  mov    -0x10(%rsi),%rdi
  mov    -0x8(%rsi),%rcx
  lea    0x1(%rcx),%rdx
  lea    -0x10(%rsi),%rsi
  jmp    L340
L10:
  mov    %rsp,%r8
  mov    $0x0,%ecx
  cmp    %r8,%rsi
  jne    L115
  sub    $0x1,%rdx
  je     L385
L392:
  add    %rax,%rdx
L131:
  add    $0x1,%rax
  movb   $0x10,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L131
L126:
  test   %rdi,%rdi
  je     L362
  add    %rdx,%rdi
L178:
  add    $0x1,%rdx
  movb   $0x7c,-0x1(%rdx)
  cmp    %rdi,%rdx
  jne    L178
L114:
  movb   $0x0,(%rdi)
  lea    D4(%rip),%rcx
  jmp    L115
L320:
  mov    $0xffffffffffffffff,%rdx
  mov    $0x0,%edi
  lea    D4(%rip),%rax
  jmp    L392
L385:
  mov    %rax,%rdx
  jmp    L126
L362:
  mov    %rdx,%rdi
  jmp    L114
L110:
  mov    $0x0,%ecx
  jmp    L115
L284:
  mov    $0x0,%ecx
  jmp    L115
L239:
  mov    $0x0,%ecx
  jmp    L115
L347:
  mov    $0x0,%ecx
  jmp    L115
L371:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
char *regexp_infx2postfx(char *infx) {
  size_t alternate_cnt = 0, atomic_cnt = 0;
  static char buffer[8192];
  char *dest = buffer;
  struct {
    size_t alternate_cnt;
    size_t atomic_cnt;
  } subexpr_stack[100], *stack_ptr;
  stack_ptr = subexpr_stack;
  if (strlen(infx) >= 8192 / 2) {
    return NULL;
  }
  for (; *infx; infx++) {
    switch (*infx) {
    case '(':
      if (atomic_cnt > 1) {
        atomic_cnt--;
        *dest++ = 16;
      }
      if (stack_ptr >= subexpr_stack + 100) {
        return NULL;
      }
      stack_ptr->alternate_cnt = alternate_cnt;
      stack_ptr->atomic_cnt = atomic_cnt;
      stack_ptr++;
      alternate_cnt = 0;
      atomic_cnt = 0;
      break;
    case ')':
      if (stack_ptr == subexpr_stack) {
        return NULL;
      }
      if (atomic_cnt == 0) {
        return NULL;
      }
      while (--atomic_cnt > 0) {
        *dest++ = 16;
      }
      for (; alternate_cnt > 0; alternate_cnt--) {
        *dest++ = '|';
      }
      stack_ptr--;
      alternate_cnt = stack_ptr->alternate_cnt;
      atomic_cnt = stack_ptr->atomic_cnt;
      atomic_cnt++;
      break;
    case '|':
      if (atomic_cnt == 0) {
        return NULL;
      }
      while (--atomic_cnt > 0) {
        *dest++ = 16;
      }
      alternate_cnt++;
      break;
    case '*':
    case '+':
    case '?':
      if (atomic_cnt == 0) {
        return NULL;
      }
      *dest++ = *infx;
      break;
    default:
      if (atomic_cnt > 1) {
        atomic_cnt--;
        *dest++ = 16;
      }
      *dest++ = *infx;
      atomic_cnt++;
      break;
    }
  }
  if (stack_ptr != subexpr_stack) {
    return NULL;
  }
  while (--atomic_cnt > 0) {
    *dest++ = 16;
  }
  for (; alternate_cnt > 0; alternate_cnt--) {
    *dest++ = '|';
  }
  *dest = 0;
  return buffer;
}
```