Ack, i undersood that after i turned my computer off.
But: https://github.com/darktable-org/darktable/blob/master/src/common/darktable.c#L386
```
#ifndef __SSE3__
  #error "Unfortunately we depend on SSE3 instructions at this time."
  #error "Please contribute a backport patch (or buy a newer processor)."
#else
  #if (__GNUC_PREREQ(4,8) || __has_builtin(__builtin_cpu_supports))
  //FIXME: check will work only in GCC 4.8+ !!! implement manual cpuid check !!!
  //NOTE: _may_i_use_cpu_feature() looks better, but only avaliable in ICC
  if (!__builtin_cpu_supports("sse3"))
  {
    fprintf(stderr, "[dt_init] unfortunately we depend on SSE3 instructions at this time.\n");
    fprintf(stderr, "[dt_init] please contribute a backport patch (or buy a newer processor).\n");
    return 1;
  }
  #else
  //FIXME: no way to check for SSE3 in runtime, implement manual cpuid check !!!
  #endif
#endif
```
As i said yearlier, If SSE is not avaliable, DT will not build/work anyway, so drop ```#if __SSE2__```