On Wed, Aug 20, 2014 at 4:31 PM, Marc Glisse <marc.gli...@inria.fr> wrote: > On Wed, 20 Aug 2014, Richard Biener wrote: > >> On Wed, Aug 20, 2014 at 9:14 AM, Marc Glisse <marc.gli...@inria.fr> wrote: >>> >>> Hello, >>> >>> here is a new version of the patch which passed bootstrap+testsuite. I am >>> still removing the ref_maybe_used_by_stmt_p test, see the previous >>> message >>> for a discussion. >> >> >> Looks good to me. I'm still nervous about removing that check (though >> the description looks odd - if the stmt kills the lhs and it also uses >> it then if this is not an exact overlap it's undefined > > > I hadn't realized that. Note that this looks true if the reference is the > lhs of an assignment, but it can be wrong if the reference was computed from > a call: > > memset(p,x,5); > memmove(p+2,p,42); > > memmove would kill memset, except that... > > >> and if it is then the stmt is still dead...). > > > use_stmt would be dead in that case, not stmt.
Yeah, but we don't handle call self-assignments. Richard. > stmt: a = 42; > use_stmt: a = a; > >> So - ok if it bootstraps/tests ok. > > > -- > Marc Glisse
