https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103181
Bug ID: 103181
Summary: [9/10/11/12 Regression] wrong code at -O1 due to
conditional division by 0 being executed
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Created attachment 51762
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51762&action=edit
reduced testcase
Output:
$ x86_64-pc-linux-gnu-gcc testcase.c -O0 && ./a.out
$ x86_64-pc-linux-gnu-gcc testcase.c -O1 && ./a.out
Floating point exception
$ x86_64-pc-linux-gnu-gcc testcase.c -O2 && ./a.out
$ x86_64-pc-linux-gnu-gcc testcase.c -O3 && ./a.out
The right hand operand of || in
v += __builtin_bswap16 (s) || (S) (a / ((U){3, 0}));
is executed, even though s != 0 and it may trap.
$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64//bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r12-5136-20211110203027-gabc2f01914d-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r12-5136-20211110203027-gabc2f01914d-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20211110 (experimental) (GCC)
