https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110792
Bug ID: 110792
Summary: GCC 13 x86_32 miscompilation of Whirlpool hash
function
Product: gcc
Version: 13.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: lloyd at randombit dot net
Target Milestone: ---
Created attachment 55619
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55619&action=edit
Reproducing testcase
Attached is a reproducing testcase for an apparent miscompilation bug in GCC 13
when compiling for 32-bit x86.
Upstream issue: https://github.com/randombit/botan/issues/3637
This code is the core loop of the Whirlpool hash function.
In the attachment if `CAUSE_CODEGEN_BUG` is defined then a particular function
is defined in an anonymous namespace. When that happens, GCC apparently
generates invalid code
$ g++ -O2 -std=c++20 -m32 whirl.cpp -o whirl
$ ./whirl
19FA61D75522A466 9B44E39C1D2E1726 C530232130D407F8 9AFEE0964997F7A7
3E83BE698B288FEB CF88E3E03C4F0757 EA8964E59B63D937 08B138CC42A66EB3
# above is the correct Whirlpool hash for the empty message
$ g++ -DCAUSE_CODEGEN_BUG -O2 -std=c++20 -m32 whirl.cpp -o whirl
$ ./whirl
zsh: segmentation fault ./whirl
If compiled with Ubsan/Asan, the code is ok:
$ g++ -DCAUSE_CODEGEN_BUG -fsanitize=address -fsanitize=undefined -O2
-std=c++20 -m32 whirl.cpp -o whirl
$ ./whirl
19FA61D75522A466 9B44E39C1D2E1726 C530232130D407F8 9AFEE0964997F7A7
3E83BE698B288FEB CF88E3E03C4F0757 EA8964E59B63D937 08B138CC42A66EB3
My GCC is
$ g++ -v
Using built-in specs.
COLLECT_GCC=/bin/g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/13.1.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure
--enable-languages=ada,c,c++,d,fortran,go,lto,objc,obj-c++ --enable-bootstrap
--prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/
--with-build-config=bootstrap-lto --with-linker-hash-style=gnu
--with-system-zlib --enable-__cxa_atexit --enable-cet=auto
--enable-checking=release --enable-clocale=gnu --enable-default-pie
--enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object
--enable-libstdcxx-backtrace --enable-link-serialization=1
--enable-linker-build-id --enable-lto --enable-multilib --enable-plugin
--enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch
--disable-werror
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.1.1 20230429 (GCC)
This is the compiler from Arch Linux which is AFAIK stock GCC. The original
report related to the GCC 13 included in Alpine Edge.
