[Bug ipa/60062] New: wrong code (for code with the optimize attribute) at -O1 and above on x86_64-linux-gnu in 32-bit mode

[su at cs dot ucdavis.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60062

            Bug ID: 60062
           Summary: wrong code (for code with the optimize attribute) at
                    -O1 and above on x86_64-linux-gnu in 32-bit mode
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu

The current gcc trunk miscompiles the following code that uses the optimize
attribute on x86_64-linux at -O1 and above in 32-bit mode (but not 64-bit). 

This is a regression from 4.8.x.

It also affects 4.7.x and 4.6.x. 

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-unknown-linux-gnu/4.9.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 4.9.0 20140204 (experimental) [trunk revision 207452] (GCC) 
$ 
$ gcc-trunk -m32 -O0 small.c; a.out
hello
$ gcc-trunk -m64 -O1 small.c; a.out
hello
$ gcc-4.8 -m32 -O1 small.c; a.out
hello
$
$ gcc-trunk -m32 -O1 small.c; a.out
Segmentation fault (core dumped) 
$ gcc-4.7 -m32 -O1 small.c; a.out
Segmentation fault (core dumped)
$ gcc-4.6 -m32 -O1 small.c; a.out
Segmentation fault (core dumped)
$ 


----------------------------------


int printf(const char *, ...);

int a;

static void 
foo(const char *p1, int p2) 
{ 
  printf("%s\n", p1); 
}

__attribute__((optimize(0))) 
int 
main() 
{
  foo("hello", a);
  return 0;
}