Am 11.12.2017 um 21:58 schrieb Christo: > I'm trying to write an assembler function to read a string from program > memory using LPM and > return a shortstring result. Consider the following prototype function: > > function readProgmemStr(constref s: shortstring): shortstring; > > It appears from the generated code as if the function result location is > assigned before the > function is called, with the reference to the function result passed as first > parameter (in > R24:R25) and the reference to s passed as the second parameter (in R22:R23). > Is this indeed the > current parameter handling for shortstring function result type?
Yes. > > If so it probably warrants a mention on the AVR wiki page. Are there any > other data types that > deviates from the GCC AVR calling convention in this way? Where do the GCC AVR calling say something about how to pass shortstrings? FPC always use a first "hidden" parameter to pass e.g. pointers to storage space for data types not being returned in registers. _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
