On ELF that was already the case since getting the size of a symbol
never fails.
On MachO and COFF we could fail trying to get the section of a symbol. But
we don't really need the section, just the section number to know if two
symbols are in the same section or not.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240580 91177308-0d34-0410-b5e6-96231b3b80d8
It is perfectly possible for SHNDX to contain indexes that have the same value
as reserved st_shndx values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240544 91177308-0d34-0410-b5e6-96231b3b80d8
COFF and MachO only define symbol sizes for common symbols. Reflect that
in the class hierarchy by having a method for common symbols only in the base
and a general one in ELF.
This avoids the need of using a magic value for the size, which had a few
problems
* Most callers didn't check for it.
* The ones that did could not tell the magic value from a file actually having
that value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240529 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds the -mcpu= option to llvm-rtdyld. With this option, one
can test relocations for different types of CPUs (e.g. Mips64r6).
Patch by Vladimir Radosavljevic.
Differential Revision: http://reviews.llvm.org/D10503
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240477 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
lto_codegen_set_should_embed_uselists is introduced in r235943 but not
added to lto.exports. Add to export list to expose the API.
Reviewers: dexonsmith
Subscribers: rafael, llvm-commits
Differential Revision: http://reviews.llvm.org/D10658
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240442 91177308-0d34-0410-b5e6-96231b3b80d8
Only common symbol on MachO and COFF have a size.
For COFF we already had a custom format.
For MachO, there is no native objdump and we were printing it as ELF. Now
we only print the sizes for symbols that actually have them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240422 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
That way llvm-objdump can rely on it without adding an extra dependency
on CodeGen.
This change duplicates the FaultKind enum and the code that serializes
it to a string. I could not figure out a way to get around this without
adding a new dependency to Object
Reviewers: rafael, ab
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10619
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240364 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: I don't think anyone is relying on this behavior for bootstrapping (because I don't think it works), but if you do need it, speak now or forever hold your peace.
Reviewers: chapuni, samsonov
Reviewed By: samsonov
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10613
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240344 91177308-0d34-0410-b5e6-96231b3b80d8
The reason we need to search by name rather than by Triple::ArchType
is to handle subarchitecture correclty. There is no different ArchType
for the x86_64h architecture (it identifies itself as x86_64), or for
the various ARM subarches. The only way to get to the subarch slice
in an universal binary is to search by name.
This issue led to hard to debug and transient symbolication failures
in Asan tests (it mostly works, because the files are very similar).
This also affects the Profiling infrastucture as it is the other user
of that API.
Reviewers: samsonov, bogner
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10604
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240339 91177308-0d34-0410-b5e6-96231b3b80d8
There are 3 types of relocations on MachO
* Scattered
* Section based
* Symbol based
On ELF and COFF relocations are symbol based.
We were in the strange situation that we abstracted over two of them. This makes
section based relocations MachO only.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240149 91177308-0d34-0410-b5e6-96231b3b80d8
In a relocation target can take 3 basic forms
* A r_value in scattered relocations.
* A symbol in external relocations.
* A section is non-external relocations.
Have the dump reflect that. With this change we go from
CHECK-NEXT: Extern: 0
CHECK-NEXT: Type: X86_64_RELOC_SUBTRACTOR (5)
CHECK-NEXT: Symbol: 0x2
CHECK-NEXT: Scattered: 0
To just
// CHECK-NEXT: Type: X86_64_RELOC_SUBTRACTOR (5)
// CHECK-NEXT: Section: __data (2)
Since the relocation is with a section, we print the seciton name and don't
need to say that it is not scattered or external.
Someone motivated can add further special cases for things like
ARM64_RELOC_ADDEND and ARM_RELOC_PAIR.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240073 91177308-0d34-0410-b5e6-96231b3b80d8
The personality routine currently lives in the LandingPadInst.
This isn't desirable because:
- All LandingPadInsts in the same function must have the same
personality routine. This means that each LandingPadInst beyond the
first has an operand which produces no additional information.
- There is ongoing work to introduce EH IR constructs other than
LandingPadInst. Moving the personality routine off of any one
particular Instruction and onto the parent function seems a lot better
than have N different places a personality function can sneak onto an
exceptional function.
Differential Revision: http://reviews.llvm.org/D10429
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239940 91177308-0d34-0410-b5e6-96231b3b80d8
Directional labels can show up in symbol tables (and we have a llvm-mc test for
that). Given that, we need to make sure they are named.
With that out of the way, use setUseNamesOnTempLabels in llvm-mc so that it
too benefits from the memory saving.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239914 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.
Reviewers: rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10381
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239815 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This affects other tools so the previous C++ API has been retained as a
deprecated function for the moment. Clang has been updated with a trivial
patch (not covered by the pre-commit review) to avoid breaking -Werror builds.
Other in-tree tools will be fixed with similar patches.
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.
The first time this was committed it accidentally fixed an inconsistency in
triples in llvm-mc and this caused a failure. This inconsistency was fixed in
r239808.
Reviewers: rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10366
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239812 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
GetTarget() may modify TripleName without also updating TheTriple.
This can lead to situations where the MCObjectStreamer has a different triple
to the rest of LLVM.
This inconsistency caused sparc-little-endian.s to pass on Windows because most
of LLVM had sparcel-pc-win32 while MCObjectStreamer had "". I believe the same
kind of thing was also true of Darwin.
Reviewers: rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, rengolin, rafael
Differential Revision: http://reviews.llvm.org/D10450
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239808 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a build failure with `LLVM_ENABLE_MODULES` due to
`ProfileData::instr` conflicting with a function `instr()` in
`<curses.h>`.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239793 91177308-0d34-0410-b5e6-96231b3b80d8
This commit connects the machine function analysis pass (which creates machine
functions) to the MIR parser, which will initialize the machine functions
with the state from the MIR file and reconstruct the machine IR.
This commit introduces a new interface called 'MachineFunctionInitializer',
which can be used to provide custom initialization for the machine functions.
This commit also introduces a new diagnostic class called
'DiagnosticInfoMIRParser' which is used for MIR parsing errors.
This commit modifies the default diagnostic handling in LLVMContext - now the
the diagnostics are printed directly into llvm::errs() so that the MIR parsing
errors can be printed with colours.
Reviewers: Justin Bogner
Differential Revision: http://reviews.llvm.org/D9928
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239753 91177308-0d34-0410-b5e6-96231b3b80d8
The plugin now save the bitcode before and after optimizations and the
.o that is passed to the linker.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239726 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This affects other tools so the previous C++ API has been retained as a
deprecated function for the moment. Clang has been updated with a trivial
patch (not covered by the pre-commit review) to avoid breaking -Werror builds.
Other in-tree tools will be fixed with similar trivial patches.
This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.
Reviewers: rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10366
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239721 91177308-0d34-0410-b5e6-96231b3b80d8
into partitions. Also, add an option to clone stub definitions (not just decls)
into partitions: these definitions could be inlined in some places to avoid the
overhead of calling via the stub.
Found by inspection - no test case yet, although I plan to add a unit test for
this once the CompileOnDemand layer refactoring settles down.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239640 91177308-0d34-0410-b5e6-96231b3b80d8
As suggested by jroelofs in a prior review (D9752),
it makes sense to generally prefer multi-line format.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239632 91177308-0d34-0410-b5e6-96231b3b80d8
The underlaying issues is that this code can't really know if an OS specific or
processor specific section number should return true or false.
One option would be to assert or return an error, but that looks like over
engineering since extensions are not that common.
It seems better to have these be direct implementation of the ELF spec so that
they are natural for someone familiar with ELF reading the code.
Code that does have to handle OS/Architecture specific values can do it at
a higher level.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239618 91177308-0d34-0410-b5e6-96231b3b80d8
make_error_code(object_error) is slow because object::object_category()
uses a ManagedStatic variable. But the real problem is that the function is
called too frequently. This patch uses std::error_code() instead of
object_error::success. In most cases, we return "success", so this patch
reduces number of function calls to that function.
http://reviews.llvm.org/D10333
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239409 91177308-0d34-0410-b5e6-96231b3b80d8
Linking the debug frame section is actually very easy as we just have to
patch the start address in the FDE header and then copy the rest of the
FDE without even looking at it. The only small complexity comes from the
handling of the CIEs that we should unique across object file. This is
also really easy by using a StringMap keyed on the raw contents of the
CIE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239198 91177308-0d34-0410-b5e6-96231b3b80d8
Anyway having the type and the name of the member being the same
thing wasn't the wisest of the choices.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239190 91177308-0d34-0410-b5e6-96231b3b80d8
The main use of the YAML debug map format is for testing inside LLVM. If we have IR
files in the tests used to generate object files, then we obviously don't know the
addresses of the symbols inside the object files beforehand.
This change lets the YAML import lookup the addresses in the object files and rewrite
them. This will allow to have test that really don't need any binary input.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239189 91177308-0d34-0410-b5e6-96231b3b80d8
It will get a bit bigger in an upcoming commit. No need to have all
of that in the header.
Also move parseYAMLDebugMap() to the same place as the serialization
code. This way it will be able to share a private Context object with
it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239185 91177308-0d34-0410-b5e6-96231b3b80d8
* If the input file is missing;
* If the type of input object file can't be recognized;
* If the object file can't be parsed correctly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239065 91177308-0d34-0410-b5e6-96231b3b80d8
We already handled a section with no symbols, extend that to also handle a
section with symbols that don't include the section start.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239039 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Now users don't have to manually deal with getFirstLoadCommandInfo() /
getNextLoadCommandInfo(), calculate the number of load segments, etc.
No functionality change.
Test Plan: regression test suite
Reviewers: rafael, lhames, loladiro
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10144
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238983 91177308-0d34-0410-b5e6-96231b3b80d8
With a couple more constructors that GCC thinks are necessary.
Original commit message:
[dsymutil] Accept a YAML debug map as input instead of a binary.
To do this, the user needs to pass the new -y flag.
As it wasn't tested before, the debug map YAML deserialization was
completely buggy (mainly because the DebugMapObject has a dual
mapping that allows to search by name and by address, but only the
StringMap got populated). It's fixed and tested in this commit by
augmenting some test with a 2 stage dwarf link: a frist llvm-dsymutil
reads the debug map and pipes it in a second instance that does the
actual link without touching the initial binary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238959 91177308-0d34-0410-b5e6-96231b3b80d8
This was exposed by r238842 (which was reverted by r238900)
when doing a CMake build with -DBUILD_SHARED_LIBS=ON.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238953 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-rtdyld was relying on the default memory manager's EH frame registration,
which is host-dependent rather than target-dependent. As a result, big-endian
ELF Mips EH frames were being registered on OS X (and elsewhere). This is a
really bad idea.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238951 91177308-0d34-0410-b5e6-96231b3b80d8
To do this, the user needs to pass the new -y flag.
As it wasn't tested before, the debug map YAML deserialization was
completely buggy (mainly because the DebugMapObject has a dual
mapping that allows to search by name and by address, but only the
StringMap got populated). It's fixed and tested in this commit by
augmenting some test with a 2 stage dwarf link: a frist llvm-dsymutil
reads the debug map and pipes it in a second instance that does the
actual link without touching the initial binary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238941 91177308-0d34-0410-b5e6-96231b3b80d8
As the serialized debug map is becoming a first class citizen, a way
to cleanly dump it is required. We used -parse-only combined with
-v for that purpose before, but it dumps a lot of unrelated debug
stuff. Dumping the debug map was the only use of the -parse-only flag
anyway, so replace it with a more useful option.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238940 91177308-0d34-0410-b5e6-96231b3b80d8
The ELF spec is very clear:
-----------------------------------------------------------------------------
If the value is non-zero, it represents a string table index that gives the
symbol name. Otherwise, the symbol table entry has no name.
--------------------------------------------------------------------------
In particular, a st_name of 0 most certainly doesn't mean that the symbol has
the same name as the section.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238899 91177308-0d34-0410-b5e6-96231b3b80d8
In r233132 we started requiring a subcommand in llvm-cov, but this
made `llvm-cov --version` invalid, which is kind of silly. Print
version information in this case, as most people would expect.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238897 91177308-0d34-0410-b5e6-96231b3b80d8
Doing so will allow us to also accept a YAML debug map in input as using
YAMLIO gives us the parsing for free. Being able to have textual debug
maps will in turn allow much more control over the tests, because 1/
no need to check-in a binary containing the debug map and 2/ it will allow
to use the same objects/IR files with made-up debug-maps to test
different scenari.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238781 91177308-0d34-0410-b5e6-96231b3b80d8
Start using C++ types such as StringRef and MemoryBuffer in the C++ LTO
API. In doing so, clarify the ownership of the native object file: the caller
now owns it, not the LTOCodeGenerator. The C libLTO library has been modified
to use a derived class of LTOCodeGenerator that owns the object file.
Differential Revision: http://reviews.llvm.org/D10114
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238776 91177308-0d34-0410-b5e6-96231b3b80d8
This commit adds partial support for MachO relocations to RelocVisitor.
A simple test case is added to show that relocations are indeed being
applied and that using llvm-dwarfdump on MachO files no longer errors.
Correctness is not yet tested, due to an unrelated bug in DebugInfo,
which will be fixed with appropriate testcase in a followup commit.
Differential Revision: http://reviews.llvm.org/D8148
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238663 91177308-0d34-0410-b5e6-96231b3b80d8
If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.
Call sites were found with the ASTMatcher + some semi-automated cleanup.
memberCallExpr(
argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
hasArgument(0, bindTemporaryExpr(
hasType(recordDecl(hasNonTrivialDestructor())),
has(constructExpr()))),
unless(isInTemplateInstantiation()))
No functional change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238602 91177308-0d34-0410-b5e6-96231b3b80d8
The fuzzer is very simple, but not quite useful at the moment: it's unable
to discover "interesting" examples, as LLVMObject library is terrible at
error recovery, calling "report_fatal_error()" far too often.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238451 91177308-0d34-0410-b5e6-96231b3b80d8
Stop storing a `DIEAbbrev` in `DIE`, since the data fits neatly inside
the `DIEValue` list. Besides being a cleaner data structure (avoiding
the parallel arrays), this gives us more freedom to rearrange the
`DIEValue` list.
This fixes the temporary memory regression from 845 MB up to 879 MB, and
drops it further to 829 MB for a net memory decrease of around 1.9%
(incremental decrease around 5.7%).
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238364 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r238350, effectively reapplying r238349 after fixing
(all?) the problems, all somehow related to how I was using
`AlignedArrayCharUnion<>` inside `DIEValue`:
- MSVC can only handle `sizeof()` on types, not values. Change the
assert.
- GCC doesn't know the `is_trivially_copyable` type trait. Instead of
asserting it, add destructors.
- Call placement new even when constructing POD (i.e., the pointers).
- Instead of copying the char buffer, copy the casted classes.
I've left in a couple of `static_assert`s that I think both MSVC and GCC
know how to handle. If the bots disagree with me, I'll remove them.
- Check that the constructed type is either standard layout or a
pointer. This protects against a programming error: we really want
the "small" `DIEValue`s to be small and simple, so don't
accidentally change them not to be.
- Similarly, check that the size of the buffer is no bigger than a
`uint64_t` or a pointer. (I thought checking against
`sizeof(uint64_t)` would be good enough, but Chandler suggested that
pointers might sometimes be bigger than that in the context of
sanitizers.)
I've also committed r238359 in the meantime, which introduces a
DIEValue.def to simplify dispatching between the various types (thanks
to a review comment by David Blaikie). Without that, this commit would
be almost unintelligible.
Here's the original commit message:
--
Change `DIEValue` to be stored/passed/etc. by value, instead of
reference. It's now a discriminated union, with a `Val` field storing
the actual type. The classes that used to inherit from `DIEValue` no
longer do. There are two categories of these:
- Small values fit in a single pointer and are stored by value.
- Large values require auxiliary storage, and are stored by reference.
The only non-mechanical change is to tools/dsymutil/DwarfLinker.cpp. It
was relying on `DIEInteger`s being passed around by reference, so I
replaced that assumption with a `PatchLocation` type that stores a safe
reference to where the `DIEInteger` lives instead.
This commit causes a temporary regression in memory usage, since I've
left merging `DIEAbbrevData` into `DIEValue` for a follow-up commit. I
measured an increase from 845 MB to 879 MB, around 3.9%. The follow-up
drops it lower than the starting point, and I've only recently brought
the memory this low anyway, so I'm committing these changes separately
to keep them incremental. (I also considered swapping the commits, but
the other one first would cause a lot more code churn.)
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
--
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238362 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r238349, since it caused some errors on bots:
- std::is_trivially_copyable isn't available until GCC 5.0.
- It was complaining about strict aliasing with my use of
ArrayCharUnion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238350 91177308-0d34-0410-b5e6-96231b3b80d8
Change `DIEValue` to be stored/passed/etc. by value, instead of
reference. It's now a discriminated union, with a `Val` field storing
the actual type. The classes that used to inherit from `DIEValue` no
longer do. There are two categories of these:
- Small values fit in a single pointer and are stored by value.
- Large values require auxiliary storage, and are stored by reference.
The only non-mechanical change is to tools/dsymutil/DwarfLinker.cpp. It
was relying on `DIEInteger`s being passed around by reference, so I
replaced that assumption with a `PatchLocation` type that stores a safe
reference to where the `DIEInteger` lives instead.
This commit causes a temporary regression in memory usage, since I've
left merging `DIEAbbrevData` into `DIEValue` for a follow-up commit. I
measured an increase from 845 MB to 879 MB, around 3.9%. The follow-up
drops it lower than the starting point, and I've only recently brought
the memory this low anyway, so I'm committing these changes separately
to keep them incremental. (I also considered swapping the commits, but
the other one first would cause a lot more code churn.)
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238349 91177308-0d34-0410-b5e6-96231b3b80d8
This commit a 3rd attempt at comitting the initial MIR serialization patch.
The first commit (r237708) was reverted in 237730. Then the second commit
(r237954) was reverted in r238007, as the MIR library under CodeGen caused
a circular dependency where the CodeGen library depended on MIR and MIR
library depended on CodeGen.
This commit has fixed the dependencies between CodeGen and MIR by
reorganizing the MIR serialization code - the code that prints out
MIR has been moved to CodeGen, and the MIR library has been renamed
to MIRParser. Now the CodeGen library doesn't depend on the
MIRParser library, thus the circular dependency no longer exists.
--Original Commit Message--
MIR Serialization: print and parse LLVM IR using MIR format.
This commit is the initial commit for the MIR serialization project.
It creates a new library under CodeGen called 'MIR'. This new
library adds a new machine function pass that prints out the LLVM IR
using the MIR format. This pass is then added as a last pass when a
'stop-after' option is used in llc. The new library adds the initial
functionality for parsing of MIR files as well. This commit also
extends the llc tool so that it can recognize and parse MIR input files.
Reviewers: Duncan P. N. Exon Smith, Matthias Braun, Philip Reames
Differential Revision: http://reviews.llvm.org/D9616
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238341 91177308-0d34-0410-b5e6-96231b3b80d8
