[Bug tree-optimization/107212] [11/12/13 Regression] Wrong vectorizer code since r11-718-gc735929a2503a7d0

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107212

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  We vectorize the loop and that triggers full constant folding
leading to the wrong result somehow.

Same issue with GCC 11 when you add -ftree-vectorize or use -O3, not observed
with GCC 10.

The reduction epilogue of the SLP reduction looks duplicate wrong.