https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69322
Bug ID: 69322
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 -O3 in both 32-bit and
32-bit modes on x86_64-linux-gnu.
$: 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
g_620=0
$: gcc-trunk small.c -O3 -m64 ; ./a.out
g_620=0
$: gcc-trunk small.c -O0 ; ./a.out
g_620=1
$:
$: cat small.c
int printf(const char*, ...);
int a;
char b, d;
short c;
short fn1(int p1, int p2) { return p2 >= 2 ? p1 : p1 > p2; }
int main() {
int *e = &a, *f = &a;
b = 1;
for (; b <= 9; b++) {
c = *e != 5 || d;
*f = fn1(c || b, a);
}
printf("g_620=%lld\n", (long long)a);
return 0;
}
$:
