http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47155
Summary: likely wrong code bug Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassig...@gcc.gnu.org ReportedBy: reg...@cs.utah.edu CC: cheny...@cs.utah.edu [reg...@gamow tmp438]$ current-gcc -O0 small.c -o small [reg...@gamow tmp438]$ ./small 1 [reg...@gamow tmp438]$ current-gcc -O1 small.c -o small [reg...@gamow tmp438]$ ./small 0 [reg...@gamow tmp438]$ current-gcc -v Using built-in specs. COLLECT_GCC=current-gcc COLLECT_LTO_WRAPPER=/uusoc/exports/scratch/regehr/z/compiler-install/gcc-r168402-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-r168402-install --program-prefix=r168402- --enable-languages=c,c++ Thread model: posix gcc version 4.6.0 20110102 (experimental) (GCC) [reg...@gamow tmp438]$ cat small.c static unsigned int g_1; static signed char g_2 = 0x81; int printf(const char *format, ...); static unsigned char foo(unsigned char p1, unsigned char p2) { return p1 * p2; } int main (void) { int l_5[2]; int i; for (i = 0; i < 2; i++) l_5[i] = 1; g_1 = g_2 <= foo(-6, l_5[0]); printf("%u\n", g_1); return 0; }