I have not dug enough into the details of gcc, but I thought that flags were only visible at a low level, such as in the avr.md file, where you are defining the assembly code sequences for different effects. Thus it is possible to define a 16-bit addition instruction with an "add, adc" sequence - but you can't really make use of the carry flag after that.
Yes this is exactly what I wanted to point out. The carry is now only used in handwritten assembler (in avr.md). GCC's RTL does not know anything about the carry bit being available when it's set/cleared and when it's clobbered.
HTH, Wouter _______________________________________________ AVR-GCC-list mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/avr-gcc-list
