[r13-3476 Regression] FAIL: gcc.dg/vect/pr100756.c scan-tree-dump-not vect "epilog loop required" on Linux/x86_64

[haochen.jiang]

On Linux/x86_64,

19295e8607da2f743368fe6f5708146616aafa91 is the first bad commit
commit 19295e8607da2f743368fe6f5708146616aafa91
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Oct 24 09:51:32 2022 +0200

    tree-optimization/100756 - niter analysis and folding

caused

FAIL: gcc.dg/vect/pr100756.c -flto -ffat-lto-objects  scan-tree-dump-not vect "epilog loop required"
FAIL: gcc.dg/vect/pr100756.c scan-tree-dump-not vect "epilog loop required"

with GCC configured with

../../gcc/configure --prefix=/export/users/haochenj/src/gcc-bisect/master/master/r13-3476/usr --enable-clocale=gnu --with-system-zlib --with-demangler-in-ld --with-fpmath=sse --enable-languages=c,c++,fortran --enable-cet --without-isl --enable-libmpx x86_64-linux --disable-bootstrap

To reproduce:

$ cd {build_dir}/gcc && make check RUNTESTFLAGS="vect.exp=gcc.dg/vect/pr100756.c --target_board='unix{-m32\ -march=cascadelake}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="vect.exp=gcc.dg/vect/pr100756.c --target_board='unix{-m64\ -march=cascadelake}'"

(Please do not reply to this email, for question about this report, contact me at haochen dot jiang at intel.com)