On 2006-12-31 09:03:17 -0500, Richard Kenner wrote: > > And I doubt that GCC (or any compiler) could reliably detect code > > that checks for overflow. > > It doesn't need to "detect" all such code: all it needs to do is > ensure that it doesn't BREAK such code. And that's a far easier > condition: you just have to avoid folding a condition into TRUE or > FALSE based on assumptions about overflow.
Well, that's not equivalent. For instance, MPFR has many conditions that evaluate to TRUE or FALSE on some/many implementations (mainly because the type sizes depend on the implementation), even without the assumption that an overflow cannot occur. -- Vincent Lefèvre <[EMAIL PROTECTED]> - Web: <http://www.vinc17.org/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/> Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)
