https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102798
Bug ID: 102798
Summary: [9/10/11/12 Regression] wrong code with -O3
-fno-tree-pta -mavx512f
Product: gcc
Version: 12.0
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 51616
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51616&action=edit
auto-reduced testcase (from OpenSSL sources)
$ x86_64-pc-linux-gnu-gcc -O3 -fno-tree-pta -mavx512f testcase.c
$ gdb ./a.out
...
(gdb) r
Starting program: /home/smatz/gcc-bug/58/a.out
Program received signal SIGSEGV, Segmentation fault.
BUF_reverse (out=<optimized out>, out@entry=0x7fffffffda60 "", in=<optimized
out>, in@entry=0x0, size=size@entry=40) at testcase.c:11
11 *out-- = *in++;
(gdb) disas
Dump of assembler code for function BUF_reverse:
...
0x0000000000401200 <+96>: and $0xffffffffffffffe0,%r9
0x0000000000401204 <+100>: add %rcx,%r9
0x0000000000401207 <+103>: nopw 0x0(%rax,%rax,1)
=> 0x0000000000401210 <+112>: vmovdqu (%rdx),%ymm2
0x0000000000401214 <+116>: add $0x20,%rdx
0x0000000000401218 <+120>: sub $0x20,%rdi
0x000000000040121c <+124>: vperm2i128 $0x1,%ymm2,%ymm2,%ymm0
...
(gdb) info reg
rax 0x28 40
rbx 0x4013d0 4199376
rcx 0x0 0
rdx 0x0 0
...
$ 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-r12-4456-20211016001627-g93d183a5fff-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-r12-4456-20211016001627-g93d183a5fff-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20211016 (experimental) (GCC)
