https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43892
--- Comment #39 from Roger Sayle <roger at nextmovesoftware dot com> --- My apologies for dropping the ball on this patch (series)... My only access to PowerPC hardware is/was via the GCC compile farm, which complicates things. Shortly after David's approval, Segher enquired whether the patch could be modified to also handle -mcpu=power10 (which represents carry differently): https://gcc.gnu.org/pipermail/gcc-patches/2021-December/586868.html Trying to (also) address this then openned up a rabbit hole/can of worms related to how middle-end (and rs6000.md) represents overflow, which included a combine patch: https://gcc.gnu.org/pipermail/gcc-patches/2021-December/586572.html Soon after GCC entered stage 4 (or stage 3), and the above patches (and an unsubmitted one for power10) simply got lost in the backlog. I believe this patch is sound, but unfortunately I don't have the bandwidth/patience to (re)check it against mainline on (multiple variants of) rs6000. If one of the IBM folks could take it from here, that'd be much appreciated.
