Paul Eggert <[EMAIL PROTECTED]> writes: | Ian Lance Taylor <[EMAIL PROTECTED]> writes: | | > We could disable VRP's assumptions about signed overflow. I don't | > know what else we could do to fix this case. I don't even know how we | > could issue a useful warning. Perhaps there is a way. | | It is a knotty problem. Thanks for thinking about it. | | I'm Handwaving with a capital H here, but one possibility is | for plain -O2 to keep VRP, but disable its assumption about | signed overflow when attempting to optimize away a | comparison that comes directly from the user's code (as | opposed to a comparison coming from subscript checking and | the like).
If that is workable, it would be a good compromise. -- Gaby
