https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100342
Bug ID: 100342
Summary: [10/11 Regression] wrong code with -O2 -fno-dse
-fno-forward-propagate -mno-sse2
Product: gcc
Version: 11.1.1
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: x86_64-pc-linux-gnu
Created attachment 50712
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50712&action=edit
semi-reduced testcase
I am failing to further reduce the testcase. I checked the code and I think the
behavior is fully defined. Also I am unable to find out what exactly goes
wrong; please close the PR if you don't want to spend time on this.
On master, it stopped failing between r12-100 (BAD) and r12-159 (OK); but it
might have been just papered over.
$ x86_64-pc-linux-gnu-gcc -O2 -fno-dse -fno-forward-propagate -mno-sse2
testcase.c -Wno-psabi
$ ./a.out
Aborted
$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-11-branch/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-11-branch/binary-11-branch-20210427124134-gfb7c736c2f1-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/11.1.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-11-branch//configure --enable-languages=c,c++
--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-libsanitizer
--disable-libstdcxx-pch
--prefix=/repo/gcc-11-branch//binary-11-branch-20210427124134-gfb7c736c2f1-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.1.1 20210427 (GCC)
