[Bug tree-optimization/65177] New: [5 Regression]: extend jump thread for finite state automata causes miscompilation

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65177

            Bug ID: 65177
           Summary: [5 Regression]: extend jump thread for finite state
                    automata causes miscompilation
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: spop at gcc dot gnu.org

Hello.

Starting with r218451, http://hmmer.janelia.org/ started to be miscompiled.

Steps to reproduce:
wget
http://selab.janelia.org/software/hmmer3/3.1b1/hmmer-3.1b1-linux-intel-x86_64.tar.gz
tar xvzf hmmer-3.1b1-cygwin.tar.gz 
cd hmmer-3.1b1-cygwin
CFLAGS="-g -O1 -ftree-vrp -fexpensive-optimizations" ./configure
make
make check

and following test fails:
gdb src/impl_sse/optacc_utest 

Program received signal SIGSEGV, Segmentation fault.
0x0000000000406a2c in select_i (k=<optimized out>, i=0, gx=0x45ed60,
gm=0x470420) at generic_optacc.c:293
293      path[0] = TSCDELTA(p7P_MI, k) * MMX(i-1,k);
(gdb) bt
#0  0x0000000000406a2c in select_i (k=<optimized out>, i=0, gx=0x45ed60,
gm=0x470420) at generic_optacc.c:293
#1  p7_GOATrace (gm=0x470420, pp=pp@entry=0x466150, gx=gx@entry=0x45ed60,
tr=tr@entry=0x46e4e0) at generic_optacc.c:220
#2  0x000000000040322f in utest_optacc (go=go@entry=0x44e010,
r=r@entry=0x44e170, abc=abc@entry=0x44eb50, bg=bg@entry=0x44ed90, M=M@entry=45,
L=L@entry=50, N=19) at ./optacc.c:659
#3  0x0000000000403613 in main (argc=<optimized out>, argv=<optimized out>) at
./optacc.c:801

I really tried to reduce test case, but unfortunately it's very hard to do it
for the project.
Please tell me if you are capable of reproducing the issue?

Thanks,
Martin