Changing loop unrolling maximum increment bound highly increase code size.

freerunner — Fri, 02 Dec 2011 21:31:36 GMT

I would like to adopt the loop unrolling with simple "for" statements, with a counter increase upper bound of 18 (instead of using the default: 16) but what I see building my program is that the code size is highly increased instead of decreasing.

How can this happen?

What i've done is just putting the command "i18" in the project settings of loop unrolling and using #PRAGMA LOOP_UNROLL before the for loop I would like to unroll.

Thanks in advance

Re: Changing loop unrolling maximum increment bound highly increase code size.

NavidadRedivivu — Fri, 02 Dec 2011 21:53:21 GMT

Check how loop unrolling works. The compiler manual contains quite good examples. Wikipedia helps too. What loop unrolling does is to inline each iteration of the loop, giving up the loop control instructions, thus resulting in faster but usually much larger code.

topic Re: Changing loop unrolling maximum increment bound highly increase code size. in 8-bit Microcontrollers

Changing loop unrolling maximum increment bound highly increase code size.

Re: Changing loop unrolling maximum increment bound highly increase code size.