Re: [avr-gcc-list] Global variables and ISRs ???

[Lars Noschinski]

* Vincent Trouilliez <address@hidden> [2005-09-07 11:32]:
> Oh, that's interesting... because as soon as I compile my small
> programs, I rush to check to have a look at the assembler output, to get
> the hang of things, and am often very confused by the way the compile
> does things, it's often very obscure !
> So far I have noticed a few recurrent things...

I guess, it's easier for the compiler to do things in a consistent way.

> - everytime I test if a variable is zero or not, it AND's it with
> itself... instead of just using the dedicated 'TST' instruction.

"TST r" is an pseudo instruction and has the same opcode like an "AND
r,r".