https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69325
Bug ID: 69325
Summary: wrong code at -O3 on x86-64-linux-gnu (in 32- and
64-bit modes)
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: chengniansun at gmail dot com
Target Milestone: ---
The following code is miscompiled by the gcc trunk at -O2 and -O3 in both
32-bit and 64-bit modes.
$: gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-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 6.0.0 20160116 (experimental) [trunk revision 232466] (GCC)
$:
$: gcc-trunk small.c -O3 -m32 ; ./a.out
$: gcc-trunk small.c -O3 -m64 ; ./a.out
$: gcc-trunk small.c -O2 -m32 ; ./a.out
$: gcc-trunk small.c -O2 -m64 ; ./a.out
$: gcc-trunk small.c -O0 -m64 ; ./a.out
g_302=4
$: cat small.c
int printf(const char*, ...);
int a, b, d, f;
char c;
static int *e = &d;
int main() {
int g = -1L;
*e = g;
c = 4;
for (; c >= 14; c++)
*e = 1;
f = a == 0;
*e ^= f;
int h = ~d;
if (d)
b = h;
if (h)
printf("g_302=%llu\n", (unsigned long long)c);
return 0;
}
$:
