user: 这段汇编代码用C语言表示是什么样的？

```asm
<punycode_decode>:
  endbr64
  push   %r15
  push   %r14
  mov    %rdi,%r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %rsi,0x18(%rsp)
  mov    %rdx,0x28(%rsp)
  mov    %rcx,0x8(%rsp)
  test   %rsi,%rsi
  je     L208
  mov    %rdi,%rax
  lea    (%rdi,%rsi,1),%rdx
  jmp    L23
  nopw   0x0(%rax,%rax,1)
L56:
  add    $0x1,%rax
  cmp    %rax,%rdx
  je     L208
L23:
  cmpb   $0x0,(%rax)
  jns    L56
  xor    %ebx,%ebx
  xor    %r15d,%r15d
L37:
  mov    0x8(%rsp),%rax
  mov    %rbx,(%rax)
  add    $0x48,%rsp
  mov    %r15,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   (%rax)
L208:
  mov    0x18(%rsp),%rax
  lea    -0x1(%r14,%rax,1),%r8
  cmp    %r8,%r14
  jb     L215
  nopl   0x0(%rax,%rax,1)
L170:
  mov    0x8(%rsp),%rax
  sub    %r14,%r8
  mov    (%rax),%rbx
  cmp    %rbx,%r8
  cmovbe %r8,%rbx
  test   %rbx,%rbx
  je     L98
  mov    0x28(%rsp),%rcx
  xor    %eax,%eax
  xchg   %ax,%ax
L0:
  movzbl (%r14,%rax,1),%edx
  mov    %dl,(%rcx,%rax,1)
  add    $0x1,%rax
  cmp    %rax,%rbx
  jne    L0
L98:
  cmp    $0x1,%r8
  sbb    $0xffffffffffffffff,%r8
  mov    %r8,%r15
  cmp    %r8,0x18(%rsp)
  jbe    L37
  movq   $0x0,0x20(%rsp)
  mov    $0x48,%ebp
  movq   $0x80,0x30(%rsp)
  mov    %r14,0x10(%rsp)
L115:
  mov    0x8(%rsp),%rax
  cmp    %rbx,(%rax)
  jbe    L37
  mov    0x20(%rsp),%r13
  mov    $0x1,%r14d
  mov    $0x24,%r12d
  mov    %r15,%rax
  mov    %r14,%rdi
  mov    %r12,%r15
  mov    %rax,%r12
  mov    %r13,%r14
  mov    %rdi,%r13
  jmp    L1
  nopw   0x0(%rax,%rax,1)
L80:
  mov    %rsi,%rax
  xor    %edx,%edx
  sub    %r14,%rax
  div    %r13
  cmp    %rcx,%rax
  jb     L138
  mov    %rcx,%rax
  imul   %r13,%rax
  add    %rax,%r14
  mov    $0x1,%eax
  cmp    %r15,%rbp
  jae    L246
  lea    0x1a(%rbp),%rdx
  mov    %r15,%rax
  sub    %rbp,%rax
  cmp    %r15,%rdx
  mov    $0x1a,%edx
  cmovbe %rdx,%rax
L246:
  cmp    %rcx,%rax
  ja     L181
  mov    $0x24,%ecx
  xor    %edx,%edx
  sub    %rax,%rcx
  mov    %rsi,%rax
  div    %rcx
  cmp    %r13,%rax
  jb     L138
  mov    0x8(%rsp),%rax
  imul   %rcx,%r13
  add    $0x24,%r15
  cmp    %rbx,(%rax)
  jbe    L181
L1:
  mov    0x10(%rsp),%rax
  add    $0x1,%r12
  movsbl -0x1(%rax,%r12,1),%edi
  call   <decode_digit@plt>
  mov    %rax,%rcx
  mov    D6(%rip),%rax
  mov    (%rax),%rsi
  cmp    %rcx,%rsi
  jne    L80
  mov    %r12,%r15
  jmp    L37
  nopl   0x0(%rax)
L73:
  sub    $0x1,%r8
  cmp    %r8,%r14
  je     L143
L215:
  cmpb   $0x2d,(%r8)
  jne    L73
  jmp    L170
  nopl   0x0(%rax,%rax,1)
L181:
  mov    0x20(%rsp),%rax
  lea    0x1(%rbx),%rcx
  xor    %edx,%edx
  mov    %r14,%rdi
  mov    %rcx,%rsi
  mov    %rcx,0x20(%rsp)
  mov    %r12,%r15
  test   %rax,%rax
  sete   %dl
  sub    %rax,%rdi
  call   <adapt_bias@plt>
  mov    0x20(%rsp),%rcx
  xor    %edx,%edx
  mov    D6(%rip),%rdi
  mov    %rax,%rbp
  mov    %r14,%rax
  div    %rcx
  mov    (%rdi),%rsi
  sub    0x30(%rsp),%rsi
  cmp    %rsi,%rax
  ja     L168
  add    %rax,0x30(%rsp)
  mov    0x28(%rsp),%rax
  lea    0x1(%rdx),%rdi
  sub    %rdx,%rbx
  mov    %rdi,0x20(%rsp)
  mov    0x30(%rsp),%r14
  lea    (%rax,%rdx,1),%r12
  add    %rdi,%rax
  mov    %rbx,%rdx
  mov    %rcx,0x38(%rsp)
  mov    %rax,%rdi
  mov    %r12,%rsi
  call   <memmove@plt>
  cmp    %r15,0x18(%rsp)
  mov    %r14b,(%r12)
  mov    0x38(%rsp),%rbx
  ja     L115
  jmp    L37
  nopl   0x0(%rax)
L138:
  xor    %edi,%edi
  mov    %r12,%r15
  call   <assert@plt>
  jmp    L37
  nop
L143:
  xor    %ebx,%ebx
  xor    %r8d,%r8d
  jmp    L98
L168:
  xor    %edi,%edi
  call   <assert@plt>
  jmp    L37
```

assistant: ```c
size_t punycode_decode(const char *const src, const size_t srclen, uint32_t *const dst, size_t *const dstlen) {
  const char *p;
  size_t b, n, t;
  size_t i, k, w;
  size_t si, di;
  size_t digit;
  size_t org_i;
  size_t bias;
  for (si = 0; si < srclen; si++) {
    if (src[si] & 0x80) {
      *dstlen = 0;
      return 0;
    }
  }
  for (p = src + srclen - 1; p > src && *p != '-'; p--)
    ;
  b = p - src;
  di = ((b) < (*dstlen) ? (b) : (*dstlen));
  for (i = 0; i < di; i++) {
    dst[i] = src[i];
  }
  i = 0;
  n = 128;
  bias = 72;
  for (si = b + (b > 0); si < srclen && di < *dstlen; di++) {
    org_i = i;
    for (w = 1, k = 36; di < *dstlen; k += 36) {
      digit = decode_digit(src[si++]);
      if (digit == SIZE_MAX) {
        goto fail;
      }
      if (digit > (SIZE_MAX - i) / w) {
        assert(0 && "OVERFLOW");
        goto fail;
      }
      i += digit * w;
      if (k <= bias) {
        t = 1;
      } else if (k >= bias + 26) {
        t = 26;
      } else {
        t = k - bias;
      }
      if (digit < t) {
        break;
      }
      if (w > SIZE_MAX / (36 - t)) {
        assert(0 && "OVERFLOW");
        goto fail;
      }
      w *= 36 - t;
    }
    bias = adapt_bias(i - org_i, di + 1, org_i == 0);
    if (i / (di + 1) > SIZE_MAX - n) {
      assert(0 && "OVERFLOW");
      goto fail;
    }
    n += i / (di + 1);
    i %= (di + 1);
    memmove(dst + i + 1, dst + i, (di - i) * sizeof(uint32_t));
    dst[i++] = n;
  }
fail:
  *dstlen = di;
  return si;
}
```