https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70919
Bug ID: 70919
Summary: wrong code at -O1 on x86_64-linux-gnu in 32-bit mode
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: su at cs dot ucdavis.edu
Target Milestone: ---
The current gcc trunk miscompiles the following code on x86_64-linux-gnu at -O1
(only) in the 32-bit mode (but on in 64-bit mode).
$ 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/7.0.0/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 7.0.0 20160502 (experimental) [trunk revision 235731] (GCC)
$
$ gcc-trunk -m32 -O0 small.c; ./a.out
$ gcc-trunk -m64 -O1 small.c; ./a.out
$
$ gcc-trunk -m32 -O1 small.c
$ ./a.out
Aborted (core dumped)
$
-------------------------------------------
#pragma pack(1)
struct S0
{
int f0:24;
};
struct S1
{
int f1;
} a;
int b, c;
char
fn1 (struct S1 p1)
{
return 0;
}
int
main ()
{
c = fn1 (a);
if (b)
{
struct S0 f[3][9] =
{ { { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } },
{ { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } },
{ { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } }
};
b = f[1][8].f0;
}
struct S0 g[3][9] =
{ { { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } },
{ { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } },
{ { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } }
};
if (g[1][8].f0 != 1)
__builtin_abort ();
return 0;
}
