[r15-812 Regression] FAIL: gcc.dg/vect/vect-gather-4.c scan-tree-dump-not vect "Loop contains only SLP stmts" on Linux/x86_64

[r15-812 Regression] FAIL: gcc.dg/vect/vect-gather-4.c scan-tree-dump-not vect "Loop contains only SLP stmts" on Linux/x86_64

[haochen.jiang]

On Linux/x86_64,

c71886f2ca2e46ce1449c7064d6f1b447d02fcba is the first bad commit
commit c71886f2ca2e46ce1449c7064d6f1b447d02fcba
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Sep 29 13:13:16 2023 +0200

    Avoid splitting store dataref groups during SLP discovery

caused

FAIL: gcc.dg/vect/vect-gather-4.c -flto -ffat-lto-objects  scan-tree-dump-not vect "Loop contains only SLP stmts"
FAIL: gcc.dg/vect/vect-gather-4.c scan-tree-dump-not vect "Loop contains only SLP stmts"

with GCC configured with

../../gcc/configure --prefix=/export/users/haochenj/src/gcc-bisect/master/master/r15-812/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/vect-gather-4.c --target_board='unix{-m32\ -march=cascadelake}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="vect.exp=gcc.dg/vect/vect-gather-4.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.)
(If you met problems with cascadelake related, disabling AVX512F in command line might save that.)
(However, please make sure that there is no potential problems with AVX512.)