if or modulo, what is fastest on AVR?

i building binary alarm clock , wonder fastest use in code, modulo , divide or if's.

i used same model here timekeeping:

code: [select]


current_millis_value = millis();
 m += current_millis_value - previous_millis_value;
 seconds += m / 1000;
 m = m % 1000;
 minutes += seconds / 60;
 seconds = seconds % 60;
 hours += minutes / 60;
 minutes = minutes % 60;
 hours = hours % 24;
 previous_millis_value = current_millis_value;


as can see uses lot's of % , /. because it's faster or because it's easier read? maybe it's slower modulo (and divides), according this post, modulo quite slow.

for example, there big difference in clock cycles used these 2 examples saving end-time of 10min snooze-period (current time + 10 minutes)?:

code: [select]



//modulo alternative:
if(buttonpressed)
{            
   snoozehours = hours;
   snoozehours += (minutes+10)/60; // if snooze minutes more 60 add 1 hours
   snoozeminutes = (minutes+10)%60; // , substract 60 snooze minutes
}

// if alternative:
if(buttonpressed)
{      
     if(minutes<50)
     {
         snoozeminutes = minutes+10;
         snoozehours = hours;
     else
     {
        snoozeminutes = minutes-50; // or minutes+10-60
        snoozehours = hours+1;
     }
}
 

maybe better knowledge me on avr processors can answer?

my first thought not need worry if need resolution of 1 second.
then have plenty of time process (other) things.


sorry not answering question.

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