Hello, there's one thing I have noticed when compiling with avr-gcc-5.2.0, and it is that compared to avr-gcc.4.8.1, it generates larger binaries and optimizes worse, while using identical compilation flags, especially when under high register pressure.
Case in point: http://thilo.tjps.eu/avrtest.c This is an excerpt from one of my programs designed the show the different behaviour. Compile with: avr-gcc-5.2.0 -ggdb3 -Wall -Wno-volatile-register-var -mmcu=attiny13a -Os -o test.o -c test.c avr-gcc-4.8.1 -ggdb3 -Wall -Wno-volatile-register-var -mmcu=attiny13a -Os -o test.o -c test.c The 5.2.0 version spills many registers, while the 4.8.1 has no need to do so. I'd appreciate if you could have a look into this. About the "volatile" keyword in front of the global register variable: Feel free to try what happens when you remove this keyword. That in itself is interesting, and this behaviour is exhibited by both compiler versions. -- Best regards, Thilo Schulz _______________________________________________ AVR-GCC-list mailing list AVR-GCC-list@nongnu.org https://lists.nongnu.org/mailman/listinfo/avr-gcc-list
