<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Jun 10, 2010, at 12:49 AM, Zhongxing Xu wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div class="gmail_quote"><blockquote class="gmail_quote" style="margin-top: 0pt; margin-right: 0pt; margin-bottom: 0pt; margin-left: 0.8ex; border-left-width: 1px; border-left-style: solid; border-left-color: rgb(204, 204, 204); padding-left: 1ex; "><div class="gmail_quote"><div>This example gives me this idea: handling such constraints in the current Simple/Range constraint manager and SValuator framework perhaps is a mistake. To correctly handle overflow, we should have a new constraint manager, which have the full ability inside to handle various overflow conditions.<span class="Apple-converted-space"> </span><br><br>I suggest we complete ignore overflow cases in current constraint managers.<span class="Apple-converted-space"> </span><br><br>For the x+1>0 example, the new constraint manager should solve it according to signedness of x. If x is signed, the solution should be x \in (-1, MAX_INT], if x is unsigned, the soluction is [0, MAX_UINT]<br></div></div></blockquote></div><br>What I mean is for constaints like x + 1 > 0, we can't use simple algebraic equality to solve it. And that complexity should be put into a new constraint manager.</span></blockquote></div><br><div>I think this is reasonable. We likely will need a new ConstraintManager entirely to handle constraints between symbolic values. SimpleConstraintManager and its derivatives are meant to be simple, and provides a nice baseline to compare to for building smarter ConstraintManagers.</div></body></html>