user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<enumerate_ring_faces>:
  endbr64
  push   %r15
  mov    %r8,%r15
  push   %r14
  mov    %edi,%r14d
  push   %r13
  mov    %edx,%r13d
  push   %r12
  mov    %ecx,%r12d
  push   %rbp
  mov    %r9,%rbp
  push   %rbx
  sub    $0x18,%rsp
  cmp    $0x1,%esi
  je     L145
  mov    %esi,%r10d
  xor    %r9d,%r9d
  xor    %ebx,%ebx
  cmp    %ecx,%esi
  je     L86
L58:
  cmp    %r12d,%r9d
  jge    L165
L39:
  lea    0x1(%r9,%r9,1),%edx
  lea    0x1(%rbx,%rbx,1),%eax
  imul   %r10d,%edx
  imul   %r12d,%eax
  cmp    %eax,%edx
  jge    L165
  lea    (%r9,%r13,1),%ecx
  add    $0x1,%r9d
  mov    %r10d,0x4(%rsp)
  mov    %r15,%rdi
  mov    %r9d,%eax
  mov    %r9d,0x8(%rsp)
  mov    $0xffffffff,%r8d
  cltd
  idiv   %r12d
  mov    %ebx,%eax
  lea    (%rdx,%r13,1),%r11d
  cltd
  idiv   %r10d
  lea    (%rdx,%r14,1),%esi
  mov    %r11d,%edx
  call   *0x50(%rsp)
  test   %rbp,%rbp
  mov    0x4(%rsp),%r10d
  mov    0x8(%rsp),%r9d
  je     L58
L5:
  addl   $0x1,0x0(%rbp)
  cmp    %r12d,%r9d
  jl     L39
L165:
  cmp    %r10d,%ebx
  je     L171
  mov    %r9d,%eax
  lea    0x1(%rbx),%r11d
  mov    %r9d,0xc(%rsp)
  lea    (%rbx,%r14,1),%esi
  cltd
  mov    %r10d,0x4(%rsp)
  mov    $0xffffffff,%r8d
  mov    %r15,%rdi
  idiv   %r12d
  mov    %r11d,0x8(%rsp)
  mov    %r11d,%eax
  lea    (%rdx,%r13,1),%ecx
  cltd
  idiv   %r10d
  add    %r14d,%edx
  call   *0x50(%rsp)
  test   %rbp,%rbp
  mov    0x8(%rsp),%ebx
  mov    0x4(%rsp),%r10d
  mov    0xc(%rsp),%r9d
  jne    L5
  jmp    L58
  nopl   (%rax)
L145:
  test   %ecx,%ecx
  jle    L171
  lea    -0x1(%rcx),%eax
  xor    %ebx,%ebx
  mov    %eax,0x4(%rsp)
  nopl   (%rax)
L114:
  test   %ebx,%ebx
  lea    -0x1(%rbx),%ecx
  cmove  0x4(%rsp),%ecx
  mov    $0xffffffff,%r8d
  lea    (%rbx,%r13,1),%edx
  mov    %r14d,%esi
  mov    %r15,%rdi
  add    %r13d,%ecx
  call   *0x50(%rsp)
  test   %rbp,%rbp
  je     L120
  addl   $0x1,0x0(%rbp)
L120:
  add    $0x1,%ebx
  cmp    %ebx,%r12d
  jne    L114
L171:
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax)
L86:
  test   %esi,%esi
  jle    L171
  xor    %r12d,%r12d
  lea    -0x1(%rsi),%ebx
  nopw   0x0(%rax,%rax,1)
L128:
  mov    %r10d,0x4(%rsp)
  lea    (%r14,%r12,1),%esi
  lea    0x0(%r13,%r12,1),%edx
  test   %r12d,%r12d
  je     L82
  lea    -0x1(%r12,%r13,1),%ecx
  lea    -0x1(%r12,%r14,1),%r8d
  mov    %r15,%rdi
  call   *0x50(%rsp)
  test   %rbp,%rbp
  mov    0x4(%rsp),%r10d
  je     L127
L102:
  addl   $0x1,0x0(%rbp)
L127:
  add    $0x1,%r12d
  cmp    %r10d,%r12d
  jl     L128
  jmp    L171
  nopl   (%rax)
L82:
  lea    0x0(%r13,%rbx,1),%ecx
  lea    (%r14,%rbx,1),%r8d
  mov    %r15,%rdi
  call   *0x50(%rsp)
  test   %rbp,%rbp
  mov    0x4(%rsp),%r10d
  jne    L102
  mov    $0x1,%r12d
  jmp    L128
```

assistant: ```c
void enumerate_ring_faces(int basevertex, int steps, int prevbase, int prevsteps, void *h, int *count_ret, void (*process_face)(void *h, int v1, int v2, int v3, int v4)) {
  int i, j;
  if (steps == 1) {
    for (i = 0; i < prevsteps; i++) {
      process_face(h, basevertex, prevbase + i, prevbase + (i ? i - 1 : prevsteps - 1), -1);
      if (count_ret)
        (*count_ret)++;
    }
  } else if (steps == prevsteps) {
    for (i = 0; i < steps; i++) {
      process_face(h, basevertex + i, prevbase + i, prevbase + (i ? i - 1 : steps - 1), basevertex + (i ? i - 1 : steps - 1));
      if (count_ret)
        (*count_ret)++;
    }
  } else {
    j = 0;
    for (i = 0;; i++) {
      while (j < prevsteps && steps * (1 + 2 * j) < prevsteps * (1 + 2 * i)) {
        process_face(h, basevertex + (i % steps), prevbase + ((j + 1) % prevsteps), prevbase + j, -1);
        if (count_ret)
          (*count_ret)++;
        j++;
      }
      if (i == steps)
        break;
      process_face(h, basevertex + i, basevertex + ((i + 1) % steps), prevbase + (j % prevsteps), -1);
      if (count_ret)
        (*count_ret)++;
    }
  }
}
```