------- Comment #2 from ruud at betaresearch dot nl 2008-04-02 22:39 -------
>From Andy H <[EMAIL PROTECTED]>
[avr-gcc-list] Incorrect code by gcc?
Not a bug
According to the sources you posted,
privQueuRequestBody
void privQueuRequestBody(uint8_t uiSlot, int8_t siFreeFilling, uint16_t
uiTicksToWait) __attribute__ ( ( naked ) );
The relevant part being "naked"
That means gcc will omit prolog - which is where stack and frame pointer are
setup.
R28/29 is the frame pointer. What you see in assembler is gcc saving the
register around a call. Depending on optimization, it may choose to do this
rather than use a register (as the register would need to be saved on the
stack).
If you use naked, you must replace all of prolog/epilog by hand. (its normal
use is for assembler only functions)
Andy
--
ruud at betaresearch dot nl changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35807
