code: func MakeAlignedByteSliceCap(len int, cap int) []byte {
  	b := make([]byte, cap+ALIGN_BUFFERS-1)
  	off := int(uintptr(unsafe.Pointer(&b[0])) & (ALIGN_BUFFERS - 1))
  	if off == 0 {
  		// Already aligned
  		return b[:len]
  	} else {
  		// Need to offset the slice to make it aligned
  		off = ALIGN_BUFFERS - off
  		return b[off : len+off]
  	}
  }
docs: // Normal slice or array allocations in golang do not appear to be
  // guaranteed to be aligned (though in practice they are).  Unaligned
  // access are slow on some architectures and blow up on others.  So
  // this allocates a slice aligned to ALIGN_BUFFERS.