Good C-coding style for multiple lines if conditions

I am programming a project in C and have a problem: I've got a lot of if conditions and it might get really hard for other people to read. I haven't yet found a similar question on the internet.

Do you have an idea or example how to make my code more readable?

Here is the C Code:

if( ((g_cycle_cnt == uartTxSecondaryMsg[3][msgPos[3]].sliceNo) ||   //correct slicenumber...
    (uartTxSecondaryMsg[3][msgPos[3]].sliceNo == -1) ||             // or as fast as possible...                                            

  ( (uartTxSecondaryMsg[3][msgPos[3]].sliceNo == -2) &&
   ((uartTxSecondaryMsg[3][msgPos[3]].timeFrameBegin>=g_uptime_cnt) && 
    (uartTxSecondaryMsg[3][msgPos[3]].timeFrameEnd<=g_uptime_cnt)))) &&

   ((dataProcessingFlag & SECONDARY_MSG_ANNOUNCED_CH4) == SECONDARY_MSG_ANNOUNCED_CH4) )