Commit Graph

836 Commits

Author SHA1 Message Date
Zachary Turner
5ea46694d0 Revert r211066, 211067, 211068, 211069, 211070.
These were committed accidentally from the wrong branch before having
a review sign-off.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211072 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-16 22:49:41 +00:00
Zachary Turner
aedb5523d2 Remove some more code out into a separate CL.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211067 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-16 22:40:17 +00:00
Jingyue Wu
f6eb7e3175 Canonicalize addrspacecast ConstExpr between different pointer types
As a follow-up to r210375 which canonicalizes addrspacecast
instructions, this patch canonicalizes addrspacecast constant
expressions.

Given clang uses ConstantExpr::getAddrSpaceCast to emit addrspacecast
cosntant expressions, this patch is also a step towards having the
frontend emit canonicalized addrspacecasts.

Piggyback a minor refactor in InstCombineCasts.cpp

Update three affected tests in addrspacecast-alias.ll,
access-non-generic.ll and constant-fold-gep.ll and added one new test in
constant-fold-address-space-pointer.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211004 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-15 21:40:57 +00:00
Tim Northover
8f2a85e099 IR: add "cmpxchg weak" variant to support permitted failure.
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.

As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.

At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.

By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.

Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.

Summary for out of tree users:
------------------------------

+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210903 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 14:24:07 +00:00
Rafael Espindola
4e2b922131 Remove 'using std::errro_code' from lib.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210871 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 02:24:39 +00:00
Rafael Espindola
5c792faa0e Don't use 'using std::error_code' in include/llvm.
This should make sure that most new uses use the std prefix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210835 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 21:46:39 +00:00
Rafael Espindola
d5132f9073 Remove system_error.h.
This is a minimal change to remove the header. I will remove the occurrences
of "using std::error_code" in a followup patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210803 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 17:38:55 +00:00
Zachary Turner
070d532aaf Remove pimpl class from PassRegistry.
Since removeRegistrationListener is no longer called during static
destruction, we can get rid of the pimpl in PassRegistry.

This should clean up the code somewhat, increase clarity, and also
allows us to put the Lock as a member of the class, instead of as a
ManagedStatic.

As part of this change, the PassInfo class is moved from
PassSupport.h to its own file, to eliminate the otherwise circular
header dependency between PassRegistry.h and PassSupport.h

Reviewed by: rnk, dblaikie

Differential Revision: http://reviews.llvm.org/D4107

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210793 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 16:06:51 +00:00
Bob Wilson
23475569d5 Fix verifier for GlobalAliases to avoid recursing into global initializers.
The verifier follows GlobalAlias operands so that it can detect cycles of
alias definitions. It was doing this in a way that caused it to also recurse
through initializers for the GlobalValue aliasees, and it would fail when
an initializer refers to a global that is a declaration and not a definition.
This patch causes it to stop recursing when it hits a global definition.
<rdar://problem/17277451>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210734 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 01:46:54 +00:00
Zachary Turner
a4dc93e6b6 Do not register and de-register PassRegistrationListeners during
construction and destruction.

PassRegistrationListener is intended for use as a generic listener.
In some cases, PassRegistrationListener-derived classes were being
created, and automatically registered and de-registered in static
constructors and destructors.  Since ManagedStatics are destroyed
prior to program shutdown, this leads to errors where an attempt is
made to access a ManagedStatic that has already been destroyed.

Reviewed by: rnk, dblaikie

Differential Revision: http://reviews.llvm.org/D4106

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210724 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 00:16:36 +00:00
Zachary Turner
a876305231 Don't acquire the mutex during the destructor of PassRegistry.
This destructor is run as part of static program termination, and
so all ManagedStatics (including this lock) will have been
destroyed by llvm_shutdown.  Furthermore, if there is actually
a race condition during static program termination, then we are
just hiding a bug somewhere else, because other threads should
not be running at this point.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210717 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-11 23:03:31 +00:00
Chad Rosier
add80b4aa6 Fix assert comments in Instruction.cpp.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210684 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-11 18:26:29 +00:00
Craig Topper
27be15cd36 Convert StringMapEntry::Create to use StringRef instead of start/end pointers. Simpliies all in tree call sites. No functional change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210638 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-11 05:35:56 +00:00
Zachary Turner
63ce00b72f Revert "Remove support for runtime multi-threading."
This reverts revision r210600.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210603 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-10 23:15:43 +00:00
Zachary Turner
529e9d307e Remove support for runtime multi-threading.
This patch removes the functions llvm_start_multithreaded() and
llvm_stop_multithreaded(), and changes llvm_is_multithreaded()
to return a constant value based on the value of the compile-time
definition LLVM_ENABLE_THREADS.

Previously, it was possible to have compile-time support for
threads on, and runtime support for threads off, in which case
certain mutexes were not allocated or ever acquired.  Now, if the
build is created with threads enabled, mutexes are always acquired.

A test before/after patch of compiling a very large TU showed no
noticeable performance impact of this change.

Reviewers: rnk

Differential Revision: http://reviews.llvm.org/D4076

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210600 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-10 23:01:20 +00:00
Reid Kleckner
9de6eef6d0 Reorder Value and User fields to save 8 bytes of padding on 64-bit
Reviewered by: rafael

Differential Revision: http://reviews.llvm.org/D4073

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210501 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-09 23:32:20 +00:00
Richard Trieu
f31ecd3927 Removing an "if (!this)" check from two print methods. The condition will
never be true in a well-defined context.  The checking for null pointers
has been moved into the caller logic so it does not rely on undefined behavior.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210497 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-09 22:53:16 +00:00
Jingyue Wu
c77dec905a InstCombine: Canonicalize addrspacecast between different element types
addrspacecast X addrspace(M)* to Y addrspace(N)*

-->

bitcast X addrspace(M)* to Y addrspace(M)*
addrspacecast Y addrspace(M)* to Y addrspace(N)*

Updat all affected tests and add several new tests in addrspacecast.ll.

This patch is based on http://reviews.llvm.org/D2186 (authored by Matt
Arsenault) with fixes and more tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210375 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 21:52:55 +00:00
Rafael Espindola
6fd1b8ee48 Allow aliases to be unnamed_addr.
Alias with unnamed_addr were in a strange state. It is stored in GlobalValue,
the language reference talks about "unnamed_addr aliases" but the verifier
was rejecting them.

It seems natural to allow unnamed_addr in aliases:

* It is a property of how it is accessed, not of the data itself.
* It is perfectly possible to write code that depends on the address
of an alias.

This patch then makes unname_addr legal for aliases. One side effect is that
the syntax changes for a corner case: In globals, unnamed_addr is now printed
before the address space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210302 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 01:20:28 +00:00
Tom Roeder
5d0f7af3dc Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute.
It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables.

This also adds backend support for generating the jump-instruction tables on ARM and X86.
Note that since the jumptable attribute creates a second function pointer for a
function, any function marked with jumptable must also be marked with unnamed_addr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210280 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 19:29:43 +00:00
Evgeniy Stepanov
0eacd38666 Add missing const specifier to a const method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210265 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 14:32:15 +00:00
Rafael Espindola
dcac1523c0 Clauses in a landingpad are always Constant. Use a stricter type.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210203 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-04 18:51:31 +00:00
Patrik Hagglund
e0e4fca46a Fix gcc -Wparentheses warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210178 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-04 11:21:11 +00:00
Rafael Espindola
2d21b25393 Allow alias to point to an arbitrary ConstantExpr.
This  patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is
up to MC (or the system assembler) to decide if that expression is valid or not.

This reduces our ability to diagnose invalid uses and how early we can spot
them, but it also lets us do things like

@test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32),
                                 i32 ptrtoint (i32* @bar to i32)) to i32*)

An important implication of this patch is that the notion of aliased global
doesn't exist any more. The alias has to encode the information needed to
access it in its metadata (linkage, visibility, type, etc).

Another consequence to notice is that getSection has to return a "const char *".
It could return a NullTerminatedStringRef if there was such a thing, but when
that was proposed the decision was to just uses "const char*" for that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210062 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-03 02:41:57 +00:00
NAKAMURA Takumi
df1913982b Instruction::isIdenticalToWhenDefined(): Check getNumOperands() in advance of std::equal(op) to appease MSVC Debug build.
MSVC Debug build is confused with (possibly invalid) op_begin(), if op_begin() == op_end().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210000 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-02 01:35:34 +00:00
Rafael Espindola
1bab2d5399 Use error_code() instead of error_code::succes()
There is no std::error_code::success, so this removes much of the noise
in transitioning to std::error_code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209952 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-31 01:37:45 +00:00
Adam Nemet
23356d4d64 [X86] Auto-upgrade AVX1 vbroadcast intrinsics
They are replaced with the same IR that is generated for the
vector-initializers in avxintrin.h.

The test verifies that we get back the original instruction.  I haven't seen
this approach to be used in other auto-upgrade tests (i.e. llc + FileCheck)
but I think it's the most direct way to test this case.  I believe this should
work because llc upgrades calls during parsing.  (Other tests mostly check
that assembling and disassembling yields the upgraded IR.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209863 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-29 23:35:33 +00:00
Rafael Espindola
665d42accf [pr19844] Add thread local mode to aliases.
This matches gcc's behavior. It also seems natural given that aliases
contain other properties that govern how it is accessed (linkage,
visibility, dll storage).

Clang still has to be updated to expose this feature to C.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209759 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-28 18:15:43 +00:00
Arnaud A. de Grandmaison
d4ffb93bf7 Factor out comparison of Instruction "special" states.
No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209688 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-27 21:35:46 +00:00
Rafael Espindola
ce5ddbab6d Use existing helper function.
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209639 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-26 19:57:55 +00:00
Hans Wennborg
68b0d1d2b4 Fix some misplaced spaces around 'override'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209589 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-24 20:19:40 +00:00
Diego Novillo
c64771062b Remove LLVMContextImpl::optimizationRemarkEnabledFor.
Summary:
This patch moves the handling of -pass-remarks* over to
lib/DiagnosticInfo.cpp. This allows the removal of the
optimizationRemarkEnabledFor functions from LLVMContextImpl, as they're
not needed anymore.

Reviewers: qcolombet

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3878

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209453 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-22 17:19:01 +00:00
Diego Novillo
d16404a0e7 Add support for missed and analysis optimization remarks.
Summary:
This adds two new diagnostics: -pass-remarks-missed and
-pass-remarks-analysis. They take the same values as -pass-remarks but
are intended to be triggered in different contexts.

-pass-remarks-missed is used by LLVMContext::emitOptimizationRemarkMissed,
which passes call when they tried to apply a transformation but
couldn't.

-pass-remarks-analysis is used by LLVMContext::emitOptimizationRemarkAnalysis,
which passes call when they want to inform the user about analysis
results.

The patch also:

1- Adds support in the inliner for the two new remarks and a
   test case.

2- Moves emitOptimizationRemark* functions to the llvm namespace.

3- Adds an LLVMContext argument instead of making them member functions
   of LLVMContext.

Reviewers: qcolombet

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3682

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209442 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-22 14:19:46 +00:00
Richard Smith
651f680b79 [modules] Add module maps for LLVM. These are not quite ready for prime-time
yet, but only a few more Clang patches need to land. (I have 'ninja check'
passing locally.)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209269 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-21 02:46:14 +00:00
Nick Lewycky
fe47ebfad3 Add 'nonnull', a new parameter and return attribute which indicates that the pointer is not null. Instcombine will elide comparisons between these and null. Patch by Luqman Aden!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209185 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-20 01:23:40 +00:00
Rafael Espindola
c86235f4eb Use create methods since msvc doesn't handle delegating constructors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209076 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-17 21:29:57 +00:00
Rafael Espindola
e7a6c2f1df Handle ConstantAggregateZero when upgrading global_ctors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209075 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-17 21:00:22 +00:00
Rafael Espindola
fbd8cc0926 Reduce abuse of default values in the GlobalAlias constructor.
This is in preparation for adding an optional offset.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209073 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-17 19:57:46 +00:00
Rafael Espindola
ad6d7f58c7 Delete getAliasedGlobal.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209040 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 22:37:03 +00:00
Reid Kleckner
1ce3088669 Add comdat key field to llvm.global_ctors and llvm.global_dtors
This allows us to put dynamic initializers for weak data into the same
comdat group as the data being initialized.  This is necessary for MSVC
ABI compatibility.  Once we have comdats for guard variables, we can use
the combination to help GlobalOpt fire more often for weak data with
guarded initialization on other platforms.

Reviewers: nlewycky

Differential Revision: http://reviews.llvm.org/D3499

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209015 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 20:39:27 +00:00
Rafael Espindola
dedd6203ad Fix a warning in builds without asserts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209012 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 20:05:08 +00:00
Rafael Espindola
27c076ae40 Fix most of PR10367.
This patch changes the design of GlobalAlias so that it doesn't take a
ConstantExpr anymore. It now points directly to a GlobalObject, but its type is
independent of the aliasee type.

To avoid changing all alias related tests in this patches, I kept the common
syntax

@foo = alias i32* @bar

to mean the same as now. The cases that used to use cast now use the more
general syntax

@foo = alias i16, i32* @bar.

Note that GlobalAlias now behaves a bit more like GlobalVariable. We
know that its type is always a pointer, so we omit the '*'.

For the bitcode, a nice surprise is that we were writing both identical types
already, so the format change is minimal. Auto upgrade is handled by looking
through the casts and no new fields are needed for now. New bitcode will
simply have different types for Alias and Aliasee.

One last interesting point in the patch is that replaceAllUsesWith becomes
smart enough to avoid putting a ConstantExpr in the aliasee. This seems better
than checking and updating every caller.

A followup patch will delete getAliasedGlobal now that it is redundant. Another
patch will add support for an explicit offset.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209007 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 19:35:39 +00:00
Rafael Espindola
ab67b30df6 Change the GlobalAlias constructor to look a bit more like GlobalVariable.
This is part of the fix for pr10367. A GlobalAlias always has a pointer type,
so just have the constructor build the type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208983 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 13:34:04 +00:00
Rafael Espindola
21cfedee05 Revert "Implement global merge optimization for global variables."
This reverts commit r208934.

The patch depends on aliases to GEPs with non zero offsets. That is not
supported and fairly broken.

The good news is that GlobalAlias is being redesigned and will have support
for offsets, so this patch should be a nice match for it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208978 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 13:02:18 +00:00
Juergen Ributzka
9bc1b73c9e Add C API for thread yielding callback.
Sometimes a LLVM compilation may take more time then a client would like to
wait for. The problem is that it is not possible to safely suspend the LLVM
thread from the outside. When the timing is bad it might be possible that the
LLVM thread holds a global mutex and this would block any progress in any other
thread.

This commit adds a new yield callback function that can be registered with a
context. LLVM will try to yield by calling this callback function, but there is
no guaranteed frequency. LLVM will only do so if it can guarantee that
suspending the thread won't block any forward progress in other LLVM contexts
in the same process.

Once the client receives the call back it can suspend the thread safely and
resume it at another time.

Related to <rdar://problem/16728690>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208945 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 02:33:15 +00:00
Reid Kleckner
a9f15ce71f musttail: Fix the verification of alignment attributes
Previously this would fail with an assertion failure when trying to add
an alignment attribute without a value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208935 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-15 23:58:57 +00:00
Jiangning Liu
d5db8765d6 Implement global merge optimization for global variables.
This commit implements two command line switches -global-merge-on-external
and -global-merge-aligned, and both of them are false by default, so this
optimization is disabled by default for all targets.

For ARM64, some back-end behaviors need to be tuned to get this optimization
further enabled.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208934 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-15 23:45:42 +00:00
David Blaikie
675e527ab8 DebugInfo: Add FIXME regarding DILexicalBlock uniquing fields.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208909 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-15 20:09:55 +00:00
Juergen Ributzka
218bad2bc5 Revert "[PM] Add pass run listeners to the pass manager."
Revert the current implementation and C API. New implementation and C APIs are
in the works.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208904 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-15 17:49:20 +00:00
Rafael Espindola
834384bf5b Split GlobalValue into GlobalValue and GlobalObject.
This allows code to statically accept a Function or a GlobalVariable, but
not an alias. This is already a cleanup by itself IMHO, but the main
reason for it is that it gives a lot more confidence that the refactoring to fix
the design of GlobalAlias is correct. That will be a followup patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208716 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-13 18:45:48 +00:00