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[Bug c++/19450] New: __thread static class members
- From: "gcc-bugzilla at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 14 Jan 2005 19:14:39 -0000
- Subject: [Bug c++/19450] New: __thread static class members
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
gcc generates incorrect code for static members in some cases. Consider the
following code:
struct C {
static __thread int x;
static __thread int y;
};
__thread int C::x;
void g() {
int z = C::x;
z = C::y;
}
When this is compiled on an x86 machine with gcc -S, the body of g() is
translated as:
movl %gs:_ZN1C1xE@NTPOFF, %eax
movl %eax, -4(%ebp)
movl _ZN1C1yE, %eax
movl %eax, -4(%ebp)
note that C::x is accessed using an offset from the thread pointer, which
is correct. C::y, however, is accessed as if it were an ordinary (not
thread-local) static member, which is incorrect. I have also observed
this problem on ia64 machines, so it seems to be a general issue.
These are similar to the symptoms described in bug 13668, although that was
determined to be a glibc issue. I see no way in which glibc could be
involved here.
Environment:
System: Linux algol.uwaterloo.ca 2.6.8-1-k7 #1 Thu Nov 25 04:13:37 UTC 2004 i686 GNU/Linux
Architecture: i686
host: i486-pc-linux-gnu
build: i486-pc-linux-gnu
target: i486-pc-linux-gnu
configured with: ../gcc/configure -v --enable-languages=c,c++ --prefix=/u/rcbilson/software/gcc --enable-shared --with-system-zlib --enable-nls --without-included-gettext --enable-__cxa_atexit --enable-clocale=gnu --enable-debug i486-linux
How-To-Repeat:
Compile the above code fragment using gcc -S.
--
Summary: __thread static class members
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: rcbilson at plg dot uwaterloo dot ca
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i486-pc-linux-gnu
GCC host triplet: i486-pc-linux-gnu
GCC target triplet: i486-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19450