On Sat, 1 Mar 2008, Joseph S. Myers wrote: > On Fri, 29 Feb 2008, Mark Mitchell wrote: > > > Thanks for the explanations. It seems like tree-ssa should in theory make > > it > > easier to implement this; for example, at the point of gimplification one > > could insert checks, and then just let everything else do its thing. I > > don't > > see how libcalls and such would matter in that scheme. I'm not denying that > > this is a project, though. > > Obviously you need to keep the functions in libgcc in any event for the > sake of old object code (just as we keep __eprintf there), even if you > make GCC generate inline code rather than libcalls or remove the option > entirely. > > You also need to deal with fold, which will optimize away potentially > trapping computations with -ftrapv and runs before gimplification > (possibly in association with making fold run at gimplification time and > not before).
It should not - at least we have various tests in place to ensure fold does not remove traps nor insert traps. Of course this is a very badly tested part of the compiler, so possibly both may happen. Richard.
