avr-gcc dziwna konstrukcja

Michał Lankosz przemówił ludzkim głosem:

A do manuala zajrzałeś?

Local labels help compilers and programmers use names temporarily. They create symbols which are guaranteed to be unique over the entire scope of the input source code and which can be referred to by a simple notation. To define a local label, write a label of the form ‘N:’ (where N represents any positive integer). To refer to the most recent previous definition of that label write ‘Nb’, using the same number as when you defined the label. To refer to the next definition of a local label, write ‘Nf’—the ‘b’ stands for “backwards” and the ‘f’ stands for “forwards”.

Here is an example: 1: branch 1f 2: branch 1b 1: branch 2f 2: branch 1b

Which is the equivalent of: label_1: branch label_3 label_2: branch label_1 label_3: branch label_4 label_4: branch label_3