[r17-4165 Regression] FAIL: g++.dg/tree-ssa/noncall-store-builtin.C -std=gnu++98 scan-rtl-dump-not expand "\\(set[ \\t\\n]+\\(mem(?:/[a-z])*/c(?:/[a-z])*:" on Linux/x86_64

[Haochen Jiang]

On Linux/x86_64,

b5a11752dcb093fd0f9ce4c205a14acf9dbe702a is the first bad commit
commit b5a11752dcb093fd0f9ce4c205a14acf9dbe702a
Author: Kyrylo Tkachov <ktkac...@nvidia.com>
Date:   Thu Sep 3 18:27:37 2026 +0200

    tree-optimization: Use reference parameter bounds in trap analysis

caused

FAIL: c-c++-common/strub-mem-notrap.c  -std=gnu++20  scan-rtl-dump expand 
"\\(mem/f:[^\\n]*watermark_ptr"
FAIL: c-c++-common/strub-mem-notrap.c  -std=gnu++29  scan-rtl-dump expand 
"\\(mem/f:[^\\n]*watermark_ptr"
FAIL: c-c++-common/strub-mem-notrap.c  -std=gnu++98  scan-rtl-dump expand 
"\\(mem/f:[^\\n]*watermark_ptr"
FAIL: c-c++-common/strub-mem-notrap.c  -Wc++-compat   scan-rtl-dump expand 
"\\(mem/f:[^\\n]*watermark_ptr"
FAIL: g++.dg/tree-ssa/noncall-store-builtin.C  -std=gnu++20  scan-rtl-dump-not 
expand "\\(set[ \\t\\n]+\\(mem(?:/[a-z])*/c(?:/[a-z])*:"
FAIL: g++.dg/tree-ssa/noncall-store-builtin.C  -std=gnu++29  scan-rtl-dump-not 
expand "\\(set[ \\t\\n]+\\(mem(?:/[a-z])*/c(?:/[a-z])*:"
FAIL: g++.dg/tree-ssa/noncall-store-builtin.C  -std=gnu++98  scan-rtl-dump-not 
expand "\\(set[ \\t\\n]+\\(mem(?:/[a-z])*/c(?:/[a-z])*:"

with GCC configured with

../../gcc/configure 
--prefix=/export/users3/haochenj/src/gcc-bisect/master/master/r17-4165/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="dg.exp=c-c++-common/strub-mem-notrap.c 
--target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=c-c++-common/strub-mem-notrap.c --target_board='unix{-m32\ 
-march=cascadelake}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=c-c++-common/strub-mem-notrap.c 
--target_board='unix{-m64}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=c-c++-common/strub-mem-notrap.c --target_board='unix{-m64\ 
-march=cascadelake}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=g++.dg/tree-ssa/noncall-store-builtin.C 
--target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=g++.dg/tree-ssa/noncall-store-builtin.C 
--target_board='unix{-m32\ -march=cascadelake}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=g++.dg/tree-ssa/noncall-store-builtin.C 
--target_board='unix{-m64}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=g++.dg/tree-ssa/noncall-store-builtin.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.)