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[Bug rtl-optimization/24812] New: Optimizer creates infinite loop with -fno-strict-aliasing
- From: "cnewbold at mathworks dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 11 Nov 2005 20:51:53 -0000
- Subject: [Bug rtl-optimization/24812] New: Optimizer creates infinite loop with -fno-strict-aliasing
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
The following test program goes into an infinite loop when compiled with -O2
and -fno-strict-aliasing but works correctly if -fno-strict-aliasing is
omitted.
$ g++-3.4 -g -O2 -fno-strict-aliasing -o loop loop.C
// loop.C
class DummyType
{
public:
~DummyType() { }
};
class Foo
{
public:
Foo() : X0(0), X4(0) { }
int X0, X1, X2, X3, X4;
};
int main(int, char**)
{
{
Foo f;
DummyType d;
}
Foo f2;
bool done(false);
while (!done) {
if (f2.X4 != 0) f2.X4 = 0;
else done = true;;
}
return 0;
}
-----
Reading specs from /usr/lib/gcc/i486-linux/3.4.4/specs
Configured with: ../src/configure -v
--enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr
--libexecdir=/usr/lib --with-gxx-include-dir=/usr/include/c++/3.4
--enable-shared --with-system-zlib --enable-nls --without-included-gettext
--program-suffix=-3.4 --enable-__cxa_atexit --enable-libstdcxx-allocator=mt
--enable-clocale=gnu --enable-libstdcxx-debug --enable-java-gc=boehm
--enable-java-awt=gtk --disable-werror i486-linux
Thread model: posix
gcc version 3.4.4 20050314 (prerelease) (Debian 3.4.3-13)
--
Summary: Optimizer creates infinite loop with -fno-strict-
aliasing
Product: gcc
Version: 3.4.4
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: cnewbold at mathworks dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24812