On Tue, Jul 10, 2018 at 6:35 PM Kugan Vivekanandarajah <kugan.vivekanandara...@linaro.org> wrote: > > Hi Andrew, > > On 11 July 2018 at 11:19, Andrew Pinski <pins...@gmail.com> wrote: > > On Tue, Jul 10, 2018 at 6:14 PM Kugan Vivekanandarajah > > <kugan.vivekanandara...@linaro.org> wrote: > >> > >> On 10 July 2018 at 23:17, Richard Biener <richard.guent...@gmail.com> > >> wrote: > >> > On Tue, Jul 10, 2018 at 3:06 PM Kugan Vivekanandarajah > >> > <kugan.vivekanandara...@linaro.org> wrote: > >> >> > >> >> Hi, > >> >> > >> >> Jeff told me that the recent popcount built-in detection is causing > >> >> kernel build issues as > >> >> ERROR: "__popcountsi2" > >> >> [drivers/net/wireless/broadcom/brcm80211/brcmfmac/brcmfmac.ko] > >> >> undefined! > >> >> > >> >> I could also reproduce this. AFIK, we should check if the libfunc is > >> >> defined while checking popcount? > >> >> > >> >> I am testing the attached RFC patch. Is this reasonable? > >> > > >> > It doesn't work that way, all targets have this libfunc in libgcc. This > >> > means > >> > the kernel has to provide it. The only thing you could do is restrict > >> > replacement of CALL_EXPRs (in SCEV cprop) to those the target > >> > natively supports. > >> > >> How about restricting it in expression_expensive_p ? Is that what you > >> wanted. Attached patch does this. > >> Bootstrap and regression testing progressing. > > > > Seems like that should go into is_inexpensive_builtin instead which > > is just tested right below. > > I hought about that. is_inexpensive_builtin is used in various other > places including some inlining decision so wasn't sure if it is the > right thing. Happy to change it if that is the right thing to do.
I audited all of the users (and their users if it is used in a wrapper) and found that is_inexpensive_builtin should return false for this builtin if it is a function call in the end; there are other builtins which should be checked the similar way but I think we should not going to force you to do the similar thing for those builtins. Thanks, Andrew > > Thanks, > Kugan > > > > Thanks, > > Andrew > > > >> > >> Thanks, > >> Kugan > >> > >> > > >> > Richard. > >> > > >> >> Thanks, > >> >> Kugan > >> >> > >> >> gcc/ChangeLog: > >> >> > >> >> 2018-07-10 Kugan Vivekanandarajah <kug...@linaro.org> > >> >> > >> >> * tree-ssa-loop-niter.c (number_of_iterations_popcount): Check > >> >> if libfunc for popcount is available.
