[Bug tree-optimization/85698] [8/9 Regression] CPU2017 525.x264_r fails starting with r257581

[pthaugen at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85698

--- Comment #3 from Pat Haugen <pthaugen at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #2)
> 
> Can you help me with isolating this to a single function inside that file?
> Maybe try sticking __attribute__((optimize("no-tree-vectorize"))) on some
> functions.  Oh, there's also the vect_loop debug counter
> (-fdbg-cnt=vect_loop:N).

add4x4_idct() looks like the function, adding the attribute (or
"no-tree-slp-vectorize") to it resulted in a successful run.


> Otherwise I'll have to find a power8 machine where I can set up CPU 2017
> myself (unlikely this week due to public holidays).

Note that it also fails with -mcpu=power7, so a power8 machine is not needed.