seriously, should i bad php code?

i'm doing php work recently, formula i've seen, tend few methods. (they also tend few variables, nonetheless that's another issue.) i wondering since is, i found note "a duty parameter an lifeless duty physique takes same doing 7-8 $localvar++ operations. identical slight impetus 15 $localvar++ operations" .

is true, even php page collected cached? should i prevaricate controlling methods many illusory efficiency? i well-organized, human-readable formula methods wherever formula retard repeated. required boring formula but methods, there any programs "inline" slight bodies? proceed i good formula following dizzy adult before deployment.

by way, formula i've looking during joomla 1.5 core several wordpress plugins, i assume know they're doing.

note: i'm gratified everybody jumped doubt pronounce optimization in general, nonetheless fact we're articulate optimization interpreted languages. during slightest idea fact we're articulate php nice.