On Fri, Jun 22, 2012 at 2:39 AM, Richard Guenther <richard.guent...@gmail.com> wrote: > On Fri, Jun 22, 2012 at 11:29 AM, Jason Merrill <ja...@redhat.com> wrote: >> On 06/22/2012 01:30 AM, Richard Guenther wrote: >>>> >>>> What other issues? It enables more potential code motion, but on the >>>> other hand, causes more conservative stack reuse. As far I can tell, >>>> the handling of temporaries is added independently after the clobber >>>> for scoped variables are introduced. This option can be used to >>>> restore the older behavior (in handling temps). >>> >>> >>> Well, it does not really restore the old behavior (if you mean before >>> adding >>> CLOBBERS, not before the single patch that might have used those for >>> gimplifying WITH_CLEANUP_EXPR). You say it disables stack-slot sharing >>> for those decls but it also does other things via side-effects of no >>> longer >>> emitting the CLOBBER. I say it's better to disable the stack-slot >>> sharing. >> >> >> The patch exactly restores the behavior of temporaries from before my change >> to add CLOBBERs for temporaries. The primary effect of that change was to >> provide stack-slot sharing, but if there are other effects they are probably >> desirable as well, since the broken code depended on the old behavior. > > So you see it as workaround option, like -fno-strict-aliasing, rather than > debugging aid?
It can be used for both purposes -- if the violations are as pervasive as strict-aliasing cases (which looks like so). thanks, David > > Richard. > >> Jason
