This annotation allows the optimizer to split vtable groups, as permitted by
a change to the Itanium ABI [1] that prevents compilers from adjusting virtual
table pointers between virtual tables.
[1] https://github.com/MentorEmbedded/cxx-abi/pull/7
Differential Revision: https://reviews.llvm.org/D24431
llvm-svn: 289585
In a future change, this representation will allow us to use the new inrange
annotation on getelementptr to allow the optimizer to split vtable groups.
Differential Revision: https://reviews.llvm.org/D22296
llvm-svn: 289584
The relative vtable ABI will use a struct rather than an array as the type
of a vtable. LLVM only allows 32-bit integers as struct indices, so we need
to use 32-bit integers to get addresses of address points. In order to keep
the code simple, we might as well do that unconditionally.
It's probably a reasonable implementation limit to support no more than 2
billion virtual functions per class.
This change causes quite a bit of churn in the test suite, so I'm making
it separately.
Differential Revision: http://reviews.llvm.org/D18113
llvm-svn: 263469
After r244870 flush() will only compare two null pointers and return,
doing nothing but wasting run time. The call is not required any more
as the stream and its SmallString are always in sync.
Thanks to David Blaikie for reviewing.
llvm-svn: 244928
Functions with available_externally linkage will not be emitted to object
files (they will just be undefined symbols), so it does not make sense to
put them in comdats.
Creates a second overload of maybeSetTrivialComdat that uses the GlobalObject
instead of the Decl, and uses that in several places that had the faulty
logic.
Differential Revision: http://reviews.llvm.org/D9580
llvm-svn: 236879
Now the GEP constant utility functions require the type to be explicitly
passed (since eventually the pointer type will be opaque and not convey
the required type information). For now callers can still pass nullptr
(though none were needed here in Clang, which is nice) if
convenienc/necessary, but eventually that will be disallowed as well.
llvm-svn: 233937
This produces comdats for vtables, typeinfo, typeinfo names, and vtts.
When combined with llvm not producing implicit comdats, not doing this would
cause code bloat on ELF and link errors on COFF.
llvm-svn: 226227
Now CodeGenVTables has only one VTableContext object, which is either
Itanium or Microsoft.
Fixes a FIXME with no functionality change intended.
Ideally we could avoid the downcasts by pushing the things that
reference the Itanium vtable context into ItaniumCXXABI.cpp, but we're
not there yet.
llvm-svn: 197845
This function only makes sense there. Eventually it should no longer
be part of the CGCXXABI interface, as it is an Itanium-specific detail.
Differential Revision: http://llvm-reviews.chandlerc.com/D821
llvm-svn: 185213
optimization. Make sure to require a vtable when trying to get the address
of a VTT, otherwise we would never end up emitting the VTT.
llvm-svn: 131400
Emit them instead with the linkage of the VTT.
I'm actually really ambivalent about this; it's what GCC does, but outside
of improving code size (if the linkage is coalescing), I'm not sure it's
at all relevant. Construction vtables are naturally referenced only by the
VTT, which is itself only referenced by complete-object constructors and
destructors; giving the construction vtables possibly-external linkage is
important if you have an optimization that drills through the VTT to a
reference to a particular construction vtable which it cannot just emit
itself.
llvm-svn: 128374
independently of whether they're definitions, then teach IR generation to
ignore non-explicit visibility when emitting declarations. Use this to
make sure that RTTI, vtables, and VTTs get the right visibility.
More of rdar://problem/8613093
llvm-svn: 117781
Peter Collingbourne