https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118616
Bug ID: 118616
Summary: [15 regression] -Waggressive-loop-optimizations
warnings in tree-vect-generic.cc on x86
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Keywords: build
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: sjames at gcc dot gnu.org
Target Milestone: ---
In member function ‘operator[]’,
inlined from ‘operator[]’ at
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/vec.h:1599:20,
inlined from ‘expand_vector_conversion’ at
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/tree-vect-generic.cc:1766:39:
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/vec.h:911:23:
warning: iteration 536870912 invokes undefined behavior
[-Waggressive-loop-optimizations]
911 | return address ()[ix];
| ^
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/tree-vect-generic.cc:
In function ‘expand_vector_conversion’:
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/tree-vect-generic.cc:1764:34:
note: within this loop
1764 | for (unsigned int i = 0; i < converts.length () - 1; i++)
| ^
In member function ‘operator[]’,
inlined from ‘operator[]’ at
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/vec.h:1599:20,
inlined from ‘expand_vector_conversion’ at
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/tree-vect-generic.cc:1766:39:
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/vec.h:911:23:
warning: iteration 536870912 invokes undefined behavior
[-Waggressive-loop-optimizations]
911 | return address ()[ix];
| ^
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/tree-vect-generic.cc:
In function ‘expand_vector_conversion’:
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/gcc/tree-vect-generic.cc:1764:34:
note: within this loop
1764 | for (unsigned int i = 0; i < converts.length () - 1; i++)
| ^
---
```
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i686-pc-linux-gnu/15/lto-wrapper
Target: i686-pc-linux-gnu
Configured with:
/var/tmp/portage/sys-devel/gcc-15.0.9999/work/gcc-15.0.9999/configure
--host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --prefix=/usr
--bindir=/usr/i686-pc-linux-gnu/gcc-bin/15
--includedir=/usr/lib/gcc/i686-pc-linux-gnu/15/include
--datadir=/usr/share/gcc-data/i686-pc-linux-gnu/15
--mandir=/usr/share/gcc-data/i686-pc-linux-gnu/15/man
--infodir=/usr/share/gcc-data/i686-pc-linux-gnu/15/info
--with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/15/include/g++-v15
--disable-silent-rules --disable-dependency-tracking
--with-python-dir=/share/gcc-data/i686-pc-linux-gnu/15/python
--enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt
--disable-werror --with-system-zlib --enable-nls --without-included-gettext
--disable-libunwind-exceptions --enable-checking=release
--with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 15.0.9999 p,
commit ed499599c366116171aab1648e7fdb14b70723c8' --with-gcc-major-version-only
--enable-libstdcxx-time --enable-lto --disable-libstdcxx-pch --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
--disable-multilib --disable-fixed-point --with-arch=i686 --enable-targets=all
--enable-libgomp --disable-libssp --disable-libada --disable-cet
--disable-systemtap --enable-valgrind-annotations --disable-vtable-verify
--disable-libvtv --with-zstd --without-isl --enable-default-pie
--enable-host-pie --disable-host-bind-now --enable-default-ssp
--disable-fixincludes --with-build-config='bootstrap-O3 bootstrap-lto'
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 15.0.1 20250123 (experimental)
4d1befa436bc6526a0e7d594e5f96012a38942c6 (Gentoo 15.0.9999 p, commit
ed499599c366116171aab1648e7fdb14b70723c8)
```
