[r17-2354 Regression] FAIL: gcc.target/i386/pr81501-9b.c check-function-bodies foo on Linux/x86_64

On Linux/x86_64,

10f6223d833874199e17226fbb0c562b69a1e72f is the first bad commit
commit 10f6223d833874199e17226fbb0c562b69a1e72f
Author: Dylan Rees <[email protected]>
Date:   Mon Jul 13 09:57:18 2026 +0000

    middle-end: Eliminate redundant scalar duplication at different vector widths

caused

FAIL: gcc.target/i386/pr124407-1.c scan-rtl-dump x86_cse "\\(const_int 0 \\[0\\]\\) repeated x16"
FAIL: gcc.target/i386/pr124407-1.c scan-rtl-dump x86_cse "\\(set \\(reg:V16QI 125\\)"
FAIL: gcc.target/i386/pr81501-9b.c check-function-bodies foo

with GCC configured with

../../gcc/configure --prefix=/export/users3/haochenj/src/gcc-bisect/master/master/r17-2354/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="i386.exp=gcc.target/i386/pr124407-1.c --target_board='unix{-m64}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/pr124407-1.c --target_board='unix{-m64\ -march=cascadelake}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/pr81501-9b.c --target_board='unix{-m64}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/pr81501-9b.c --target_board='unix{-m64\ -march=cascadelake}'"

(Please directly reply to this email for question about this report.)
(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.)