Illegal instruction (int main() returns nothing, only when -O2/-O3 used)

[Коренберг Марк]

$ gcc --version
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ gcc test.c

$ gcc -O2 test.c
test.c: In function 'main':
test.c:6:1: internal compiler error: Illegal instruction
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.6/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccYojEN6.out file, please attach this to
your bugreport.

$ cat test.c
int main (void)
{
  volatile int a;
  if (a == 42)
    return 1;
}

--------------------------------
If I add "return 0;" to the end of function - problem is fixed. I understand,
that program is not correct, but, as I think, gcc should not fail on that. It
seems, it is optimizer bug.

The problem does not appear in upstream (look at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54340 )

[Matthias Klose (doko)]

I can't even reproduce this with 4.6.3-1ubuntu5 on precise on amd64.

[Zhenqiang Chen (zhenqiang-chen)]

Thank you for the bug report. I can not reproduce this with gcc-linaro-4.6-2012.08 and gcc-linaro-4.7-2012.08 on ARM.

[Viktor (vchong)]

Closing per above comments and end of support.