https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66877
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
For some reason you get widening shifts recognized while I get them not
supported by the HW (with the cross at -O2 -ftree-vectorize). -mfpu=neon
doesn't help.
I still can't reproduce your dump file with
/space/rguenther/src/svn/trunk3/configure --target=arm-none-eabi
gcc> /cc1 -quiet t.c -O2 -ftree-vectorize -fdump-tree-vect-details
-fno-vect-cost-model -fno-common -mfpu=neon -march=armv7-a
please advise further.
Also you might want to try if guarding the check with { target !
vect_widen_shift } and adding a variant for vect_widen_shift to scan for 1
occurence fixes the
testcase. That would make sense to me.
