https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70586
Bug ID: 70586
Summary: wrong code at -O2 and -O3 on x86_64-linux-gnu in
32-bit 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 trunk at -O2 and -O3 on
x86_64-linux-gnu in 32-bit and 64-bit modes.
This also affects gcc-4.8 and later versions.
$: 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-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 6.0.0 20160407 (experimental) [trunk revision 234805] (GCC)
$:
$: gcc-trunk -w -m32 small.c -O3 ; ./a.out
Floating point exception (core dumped)
$: gcc-trunk -w -m32 small.c -O2 ; ./a.out
Floating point exception (core dumped)
$: gcc-trunk -w -m32 small.c -O1 ; ./a.out
$: gcc-4.8 -w small.c -O3 ; ./a.out
Floating point exception (core dumped)
$: gcc-4.7 -w small.c -O3 ; ./a.out
$:
$: cat small.c
int a, e, f;
short b, c, d;
int fn1(p1, p2) { return p2 == 0 || p1 && p2 == 1 ? p1 : p1 % p2; }
static short fn2() {
int g, h, i = fn1(c, f);
f = fn1(d, 2);
g = fn1(b, c);
h = fn1(g > 0, c);
c = (3 >= h ^ 7) <= fn1(i, c);
if (fn1(e, 1))
return a;
}
int main() {
fn2();
return 0;
}
$:
