Re: SSA_NAMES: should there be an unused, un-free limbo?

2006-12-24 Thread Zdenek Dvorak
Hello, > > > I think this might be a good idea. I think that this requires > > > a lot of changes (basically going through all uses of bsi_remove > > > and remove_phi_node and checking them), but it would be cleaner > > > than the current situation. > > Agreed. Tedious work, but it shouldn't be

Re: GCC optimizes integer overflow: bug or feature?

2006-12-24 Thread Vincent Lefevre
On 2006-12-20 23:40:45 +0100, Marcin Dalecki wrote: > However it's a quite common mistake to forget how > "bad" floats "model" real numbers. It depends on what you are doing. For instance, thanks to the IEEE-754 standard, it is possible to perform exact computations with floats. By doing unsafe

Re: GCC optimizes integer overflow: bug or feature?

2006-12-24 Thread Vincent Lefevre
On 2006-12-21 17:42:15 -0500, Robert Dewar wrote: > Marcin Dalecki wrote: > > >Of course I didn't think about a substitute for ==. Not! However I think > >that checks for |x-y| < epsilion, could be really given a significant > >speed edge > >if done in a single go in hardware. > > One thing to

Re: GCC optimizes integer overflow: bug or feature?

2006-12-24 Thread Vincent Lefevre
On 2006-12-19 10:44:25 -0800, Paul Eggert wrote: > Sure, but that is trickier. In many cases code operates on > types like time_t that are signed on some platforms and > unsigned on others. It's easy for such code to test for > overflow if you assume wraparound arithmetic, as code like > { sum =