// 
// sub_1800189D0 from 0x1800189d0 to 0x180018c07 (567 bytes)
// 
// 5 xrefs:
// > sub_180017930 @ 0x18001794d
// > <???> @ 0x18002f370
// > <???> @ 0x18002f380
// > <???> @ 0x18002f398
// > <???> @ 0x18004ab54
// 
// This function is hookable on this platform!
// 
// Using BromaIDA 8.0.0 @ https://github.com/Stazzical/BromaIDA
// Using bindings at commit ba9f177b at Thu Jul 16 22:52:06 2026 from https://github.com/geode-sdk/bindings
// 

void __fastcall sub_1800189D0(__int64 a1, _BYTE *a2, const void *a3, size_t a4)
{
  _BYTE *v4; // r15
  _BYTE *v6; // r13
  __int64 v8; // rcx
  size_t v11; // rsi
  signed __int64 v12; // r12
  unsigned __int64 v13; // rcx
  unsigned __int64 v14; // rdx
  size_t v15; // rcx
  void *v16; // rax
  char *v17; // rdi
  size_t v18; // r8
  const void *v19; // rdx
  char *v20; // rcx
  _BYTE *v21; // rcx
  signed __int64 v22; // rsi
  char *v23; // rdi
  size_t v25; // [rsp+88h] [rbp+20h]

  if ( a4 )
  {
    v4 = *(_BYTE **)(a1 + 8);
    v6 = *(_BYTE **)a1;
    v8 = *(_QWORD *)(a1 + 16);
    if ( a4 > v8 - (__int64)v4 )
    {
      v11 = 0x7FFFFFFFFFFFFFFFLL;
      v12 = v4 - v6;
      if ( a4 > 0x7FFFFFFFFFFFFFFFLL - (v4 - v6) )
        sub_180003530();
      v13 = v8 - (_QWORD)v6;
      v25 = v12 + a4;
      v14 = v13 >> 1;
      if ( v13 <= 0x7FFFFFFFFFFFFFFFLL - (v13 >> 1) )
      {
        v11 = v12 + a4;
        if ( v14 + v13 >= v12 + a4 )
          v11 = v14 + v13;
        if ( v11 < 0x1000 )
        {
          if ( v11 )
            v17 = (char *)operator new(v11);
          else
            v17 = nullptr;
          goto LABEL_16;
        }
        v15 = v11 + 39;
        if ( v11 + 39 < v11 )
          Concurrency::cancel_current_task();
      }
      else
      {
        v15 = 0x8000000000000026uLL;
      }
      v16 = operator new(v15);
      if ( !v16 )
        goto LABEL_26;
      v17 = (char *)(((unsigned __int64)v16 + 39) & 0xFFFFFFFFFFFFFFE0uLL);
      *((_QWORD *)v17 - 1) = v16;
LABEL_16:
      memmove(&v17[a2 - v6], a3, a4);
      if ( a4 == 1 && a2 == v4 )
      {
        v18 = v4 - v6;
        v19 = v6;
        v20 = v17;
      }
      else
      {
        memmove(v17, v6, a2 - v6);
        v20 = &v17[a2 - v6 + a4];
        v18 = v4 - a2;
        v19 = a2;
      }
      memmove(v20, v19, v18);
      v21 = *(_BYTE **)a1;
      if ( !*(_QWORD *)a1 )
        goto LABEL_25;
      if ( *(_QWORD *)(a1 + 16) - (_QWORD)v21 < 0x1000u )
      {
LABEL_24:
        j_j_free(v21);
LABEL_25:
        *(_QWORD *)a1 = v17;
        *(_QWORD *)(a1 + 8) = &v17[v25];
        *(_QWORD *)(a1 + 16) = &v17[v11];
        return;
      }
      if ( (unsigned __int64)&v21[-*((_QWORD *)v21 - 1) - 8] <= 0x1F )
      {
        v21 = *((_BYTE **)v21 - 1);
        goto LABEL_24;
      }
LABEL_26:
      invalid_parameter_noinfo_noreturn();
    }
    v22 = v4 - a2;
    if ( a4 >= v4 - a2 )
    {
      v23 = &a2[a4];
      memmove(&a2[a4], a2, v4 - a2);
      *(_QWORD *)(a1 + 8) = &v23[v22];
    }
    else
    {
      memmove(v4, &v4[-a4], a4);
      *(_QWORD *)(a1 + 8) = &v4[a4];
      memmove(&v4[-(v22 - a4)], a2, v22 - a4);
    }
    memmove(a2, a3, a4);
  }
}