Adjusting gcc flags to eliminate optimizations is another way to go. Adding -fwrapv would be an excellent start. Lack of this flag breaks most code which checks for integer wrap-around.
Lack of the flag does not break any valid C code, only code making unwarranted assumptions (i.e., buggy code).
The compiler "knows" that signed integers don't ever wrap, and thus eliminates any code which checks for values going negative after a wrap-around.
You cannot assume it eliminates such code; the compiler is free to do whatever it wants in such a case. You should typically write such a computation using unsigned types, FWIW. Anyway, with 4.1 you shouldn't see frequent problems due to "not using -fwrapv while my code is broken WRT signed overflow" yet; and if/when problems start to happen, to "correct" action to take is not to add the compiler flag, but to fix the code. Segher - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
