[r17-1353 Regression] FAIL: g++.dg/warn/Warray-bounds15.C -std=gnu++26 (test for warnings, line 38) on Linux/x86_64

[Haochen Jiang]

On Linux/x86_64,

106970adca69c9c577e6c75f4e69a08cd9ea2df0 is the first bad commit
commit 106970adca69c9c577e6c75f4e69a08cd9ea2df0
Author: Martin Uecker <uec...@tugraz.at>
Date:   Wed Jun 3 17:57:30 2026 +0200

    c: harmonize handling of arrays

caused

FAIL: gcc.dg/debug/ctf/ctf-array-2.c scan-assembler-times 0x12000000[\t 
]+[^\n]*ctt_info 2
FAIL: gcc.dg/debug/ctf/ctf-array-2.c scan-assembler-times [\t ]0[\t 
]+[^\n]*cta_nelems 2
FAIL: gcc.dg/Warray-bounds-52.c (test for excess errors)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 19)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 20)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 21)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 34)
FAIL: gcc.dg/Warray-bounds-52.c  (test for warnings, line 35)
FAIL: gcc.dg/Warray-bounds-53.c (test for excess errors)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 19)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 20)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 21)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 34)
FAIL: gcc.dg/Warray-bounds-53.c  (test for warnings, line 35)
FAIL: g++.dg/warn/Warray-bounds15.C  -std=gnu++14  (test for warnings, line 38)
FAIL: g++.dg/warn/Warray-bounds15.C  -std=gnu++20  (test for warnings, line 38)
FAIL: g++.dg/warn/Warray-bounds15.C  -std=gnu++26  (test for warnings, line 38)

with GCC configured with

../../gcc/configure 
--prefix=/export/users3/haochenj/src/gcc-bisect/master/master/r17-1353/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="ctf.exp=gcc.dg/debug/ctf/ctf-array-2.c 
--target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="ctf.exp=gcc.dg/debug/ctf/ctf-array-2.c --target_board='unix{-m32\ 
-march=cascadelake}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=gcc.dg/Warray-bounds-52.c --target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=gcc.dg/Warray-bounds-52.c --target_board='unix{-m32\ 
-march=cascadelake}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=gcc.dg/Warray-bounds-53.c --target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=gcc.dg/Warray-bounds-53.c --target_board='unix{-m32\ 
-march=cascadelake}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=g++.dg/warn/Warray-bounds15.C --target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check 
RUNTESTFLAGS="dg.exp=g++.dg/warn/Warray-bounds15.C --target_board='unix{-m32\ 
-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.)