https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85190
--- Comment #3 from amker at gcc dot gnu.org --- (In reply to Rainer Orth from comment #0) > The gcc.dg/vect/pr81196.c testcase started to FAIL between 20180326 > (r258856) and 20180327 (r258886) > on a couple of targets: > > +FAIL: gcc.dg/vect/pr81196.c -flto -ffat-lto-objects scan-tree-dump-times > vect "vectorized 1 loops" 2 > > gcc.dg/vect/pr81196.c: pattern found 0 times > > +FAIL: gcc.dg/vect/pr81196.c scan-tree-dump-times vect "vectorized 1 loops" 2 > > I'm seeing it on Solaris/x86 (32 and 64-bit), and there are similar > testresults > for FreeBSD, Linux/x86, Linux/PowerPC64, and SPU. Hmm, what options did you use? For example, @r258886 I configured powerpc64 like: $ ../gcc/configure --enable-languages=c,fortran,c++ --with-cpu=power8 --disable-bootstrap Then compile the test case with below options: ./powerpc64le-unknown-linux-gnu-gcc -S -O2 -ftree-vectorize pr81196.c -o pr81196.S -fdump-tree-ifcvt -fdump-tree-vect-details -flto -ffat-lto-objects -mcpu=power6/7/8 power6/power7 would fail, but on power8 loops are vectorized. Problem is, on power6/power7, the case would fail even for r258856 as you bisected.
