[Bug middle-end/55011] New: GCC in an infinite loop at -O2

[antoine.balestrat at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55011



             Bug #: 55011

           Summary: GCC in an infinite loop at -O2

    Classification: Unclassified

           Product: gcc

           Version: 4.8.0

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: middle-end

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: antoine.balest...@gmail.com





GCC 4.8.0 as of 20121021 seems to be stuck in an infinite loop while compiling

the following testcase at -O2 (works at -O1 and -O3) :



$ cat infloop.c

char a;



void f(void)

{

    char b = 2;



    for(;;)

    {

        unsigned short s = 1, *p = &s, *i;



        for(*i = 0; *i < 4; ++*i)

            if(a | (*p /= (b += !!a)) <= 63739)

                return;



        if(!s)

            a = 0;



        for(;;);

    }

}



$ ulimit -t 120



$ xgcc -O2 infloop.c



... 2 minutes later :



gcc: internal compiler error: CPU time limit exceeded (program cc1)

linux-vdso.so.1: No such file or directory

0x40b937 execute

    ../../srcdir/gcc/gcc.c:2739

0x40c7be do_spec_1

    ../../srcdir/gcc/gcc.c:4534

0x40f0d5 process_brace_body

    ../../srcdir/gcc/gcc.c:5782

0x40f0d5 handle_braces

    ../../srcdir/gcc/gcc.c:5696

0x40d397 do_spec_1

    ../../srcdir/gcc/gcc.c:5179

0x40f0d5 process_brace_body

    ../../srcdir/gcc/gcc.c:5782

0x40f0d5 handle_braces

    ../../srcdir/gcc/gcc.c:5696

0x40d397 do_spec_1

    ../../srcdir/gcc/gcc.c:5179

0x40cff7 do_spec_1

    ../../srcdir/gcc/gcc.c:5284

0x40f0d5 process_brace_body

    ../../srcdir/gcc/gcc.c:5782

0x40f0d5 handle_braces

    ../../srcdir/gcc/gcc.c:5696

0x40d397 do_spec_1

    ../../srcdir/gcc/gcc.c:5179

0x40f0d5 process_brace_body

    ../../srcdir/gcc/gcc.c:5782

0x40f0d5 handle_braces

    ../../srcdir/gcc/gcc.c:5696

0x40d397 do_spec_1

    ../../srcdir/gcc/gcc.c:5179

0x40f0d5 process_brace_body

    ../../srcdir/gcc/gcc.c:5782

0x40f0d5 handle_braces

    ../../srcdir/gcc/gcc.c:5696

0x40d397 do_spec_1

    ../../srcdir/gcc/gcc.c:5179

0x40f0d5 process_brace_body

    ../../srcdir/gcc/gcc.c:5782

0x40f0d5 handle_braces

    ../../srcdir/gcc/gcc.c:5696

Please submit a full bug report,

with preprocessed source if appropriate.

Please include the complete backtrace with any bug report.

See <http://gcc.gnu.org/bugs.html> for instructions.



Please let me know if you need more information !