https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121322
Bug ID: 121322
Summary: UBSAN error in find_bswap_or_nop (shift exponent 64 is
too large for 64-bit type 'long unsigned int')
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: sjames at gcc dot gnu.org
Blocks: 63426
Target Milestone: ---
```
$ export
UBSAN_OPTIONS="halt_on_error=1:abort_on_error=1:print_summary=1:print_stacktrace=1"
$ g++ -m32 -c ./lib/Object/CMakeFiles/LLVMObject.dir/ELFObjectFile.cpp.ii -O2
/var/tmp/portage/sys-devel/gcc-16.0.9999/work/gcc-16.0.9999/gcc/gimple-ssa-store-merging.cc:1065:35:
runtime error: shift exponent 64 is too large for 64-bit type 'long unsigned
int'
#0 0x559ac5cb0878 in find_bswap_or_nop
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/gimple-ssa-store-merging.cc:1065
#1 0x559acd8ee332 in execute
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/gimple-ssa-store-merging.cc:1625
#2 0x559ac82cbf30 in execute_one_pass(opt_pass*)
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/passes.cc:2648
#3 0x559ac82cedb0 in execute_pass_list_1
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/passes.cc:2757
#4 0x559ac82cedf7 in execute_pass_list_1
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/passes.cc:2758
#5 0x559ac82ceebc in execute_pass_list(function*, opt_pass*)
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/passes.cc:2768
#6 0x559ac6eeaa8e in cgraph_node::expand()
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/cgraphunit.cc:1859
#7 0x559ac6eeaa8e in cgraph_node::expand()
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/cgraphunit.cc:1812
#8 0x559ac6efc7ed in expand_all_functions
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/cgraphunit.cc:2042
#9 0x559ac6efc7ed in symbol_table::compile()
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/cgraphunit.cc:2419
#10 0x559ac6efd5b0 in symbol_table::compile()
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/cgraphunit.cc:2329
#11 0x559ac6efd5b0 in symbol_table::finalize_compilation_unit()
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/cgraphunit.cc:2608
#12 0x559ac892f690 in compile_file
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/toplev.cc:480
#13 0x559ac5cf2814 in do_compile
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/toplev.cc:2220
#14 0x559ac5cf2814 in toplev::main(int, char**)
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/toplev.cc:2383
#15 0x559ac5cf6024 in main
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/main.cc:39
#16 0x7f4e522277ca (/usr/lib64/libc.so.6+0x277ca)
#17 0x7f4e52227879 in __libc_start_main (/usr/lib64/libc.so.6+0x27879)
#18 0x559ac5cf6524 in _start
(/usr/libexec/gcc/x86_64-pc-linux-gnu/16/cc1plus+0x7b67524)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
/var/tmp/portage/sys-devel/gcc-16.0.9999/work/gcc-16.0.9999/gcc/gimple-ssa-store-merging.cc:1065:35
during GIMPLE pass: bswap
In file included from
/var/tmp/portage/llvm-core/llvm-20.1.8/work/llvm/lib/Object/ELFObjectFile.cpp:13:
/var/tmp/portage/llvm-core/llvm-20.1.8/work/llvm/include/llvm/Object/ELFObjectFile.h:
In member function ‘uint64_t
llvm::object::ELFObjectFile<ELFT>::getRelocationType(llvm::object::DataRefImpl)
const [with ELFT = llvm::object::ELFType<llvm::endianness::big, true>]’:
/var/tmp/portage/llvm-core/llvm-20.1.8/work/llvm/include/llvm/Object/ELFObjectFile.h:1132:10:
internal compiler error: Aborted
1132 | uint64_t ELFObjectFile<ELFT>::getRelocationType(DataRefImpl Rel) const
{
| ^~~~~~~~~~~~~~~~~~~
0x559ace2769ef internal_error(char const*, ...)
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/diagnostic-global-context.cc:534
0x559ac892d2d7 crash_signal
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/toplev.cc:323
0x559ac5ceec2e __sanitizer::Abort()
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cpp:163
0x559ace73ee6b __sanitizer::Die()
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/libsanitizer/sanitizer_common/sanitizer_termination.cpp:58
0x559ace73fab6 __ubsan::ScopedReport::~ScopedReport()
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/libsanitizer/ubsan/ubsan_diag.cpp:402
0x559ace737ba1 handleShiftOutOfBoundsImpl
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/libsanitizer/ubsan/ubsan_handlers.cpp:364
0x559ace738b0e __ubsan_handle_shift_out_of_bounds
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/libsanitizer/ubsan/ubsan_handlers.cpp:370
0x559ac5cb0878 find_bswap_or_nop
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/gimple-ssa-store-merging.cc:1065
0x559acd8ee332 execute
/usr/src/debug/sys-devel/gcc-16.0.9999/gcc-16.0.9999/gcc/gimple-ssa-store-merging.cc:1625
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://bugs.gentoo.org/> for instructions.
```
```
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/16/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-pc-linux-gnu
Configured with:
/var/tmp/portage/sys-devel/gcc-16.0.9999/work/gcc-16.0.9999/configure
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr
--bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/16
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/16/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/16
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/16/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/16/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16
--disable-silent-rules --disable-dependency-tracking
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/16/python
--enable-libphobos --enable-objc-gc
--enable-languages=c,c++,d,objc,obj-c++,fortran,ada,rust --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 16.0.9999 p, commit
8cda62318174b911a7cba57fcf70efd38f265f0e' --with-gcc-major-version-only
--enable-libstdcxx-time --enable-lto --disable-libstdcxx-pch --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
--enable-multilib --with-multilib-list=m32,m64 --disable-fixed-point
--enable-targets=all --enable-offload-defaulted
--enable-offload-targets=nvptx-none --enable-libgomp --disable-libssp
--enable-libada --enable-cet --disable-systemtap --enable-valgrind-annotations
--disable-vtable-verify --disable-libvtv --with-zstd --without-isl
--enable-default-pie --enable-host-pie --enable-host-bind-now
--enable-default-ssp --disable-fixincludes
--with-gxx-libcxx-include-dir=/usr/include/c++/v1
--with-build-config='bootstrap-ubsan bootstrap-cet'
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.0 20250730 (experimental)
7aa9565a62ea2ce04e2ddf61e1932bc123374988 (Gentoo 16.0.9999 p, commit
8cda62318174b911a7cba57fcf70efd38f265f0e)
```
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63426
[Bug 63426] [meta-bug] Issues found with -fsanitize=undefined
