Summary:
We need to emit barrier if the union field
is CXXRecordDecl because it might have vptrs. The testcode
was wrongly devirtualized. It also proves that having different
groups for different dynamic types is not sufficient.
Reviewers: rjmccall, rsmith, mehdi_amini
Subscribers: amharc, cfe-commits
Differential Revision: https://reviews.llvm.org/D31830
llvm-svn: 304448
Re-commit r303463 now that LLVM is fixed and adjust some lit tests.
llvm::TargetLibraryInfo needs to know the size of wchar_t to work on
functions like `wcslen`. This patch changes clang to always emit the
wchar_size module flag (it would only do so for ARM previously).
This also adds an `assert()` to ensure the LLVM defaults based on the
target triple are in sync with clang.
Differential Revision: https://reviews.llvm.org/D32982
llvm-svn: 303478
Much to my surprise, '-disable-llvm-optzns' which I thought was the
magical flag I wanted to get at the raw LLVM IR coming out of Clang
deosn't do that. It still runs some passes over the IR. I don't want
that, I really want the *raw* IR coming out of Clang and I strongly
suspect everyone else using it is in the same camp.
There is actually a flag that does what I want that I didn't know about
called '-disable-llvm-passes'. I suspect many others don't know about it
either. It both does what I want and is much simpler.
This removes the confusing version and makes that spelling of the flag
an alias for '-disable-llvm-passes'. I've also moved everything in Clang
to use the 'passes' spelling as it seems both more accurate (*all* LLVM
passes are disabled, not just optimizations) and much easier to remember
and spell correctly.
This is part of simplifying how Clang drives LLVM to make it cleaner to
wire up to the new pass manager.
Differential Revision: https://reviews.llvm.org/D28047
llvm-svn: 290392
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
Ensure that the vptr store in the most-derived constructor is not behind
an invariant group barrier. Previously, the base-most vptr store would
be the one behind no barrier, and that could result in the creator of
the object thinking it had the base-most vtable.
This bug caused clang call pure virtual functions when called from
constructor body.
http://reviews.llvm.org/D13373
llvm-svn: 249197
It is dangerous to do LTO on code with strict-vtable-pointers, because
one module has invariant.group.barriers, and the other one not.
In the future I want to just strip all invariant.group metadata from
vptrs loads/stores and get rid of invariant.group.barrier calls.
http://reviews.llvm.org/D12580
llvm-svn: 247724
Yaxun Liu