I don't think there's anything wrong with the testcase. The -O2 result is
wrong.
[reg...@gamow ~]$ current-gcc -v
Using built-in specs.
COLLECT_GCC=current-gcc
COLLECT_LTO_WRAPPER=/uusoc/exports/scratch/regehr/z/compiler-install/gcc-r164319-install/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../configure --with-libelf=/usr/local --enable-lto
--prefix=/home/regehr/z/compiler-install/gcc-r164319-install
--program-prefix=r164319- --enable-languages=c,c++
Thread model: posix
gcc version 4.6.0 20100915 (experimental) (GCC)
[reg...@gamow ~]$ current-gcc -O1 small.c -o small
[reg...@gamow ~]$ ./small
1
[reg...@gamow ~]$ current-gcc -O2 small.c -o small
[reg...@gamow ~]$ ./small
0
[reg...@gamow ~]$ cat small.c
int printf(const char *format, ...);
static int g_7;
static int *volatile g_6 = &g_7;
static int func_53(int *p_58)
{
return *p_58;
}
int main(void)
{
*g_6 = 1;
printf("%d\n", func_53(&g_7));
return 0;
}
--
Summary: possible wrong code bug
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: regehr at cs dot utah dot edu
GCC build triplet: x86_64-unknown-linux-gnu
GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45687
