Commit Graph

164 Commits

Author SHA1 Message Date
Konstantin Zhuravlyov bb80d3e1d3 Enhance synchscope representation
OpenCL 2.0 introduces the notion of memory scopes in atomic operations to
  global and local memory. These scopes restrict how synchronization is
  achieved, which can result in improved performance.

  This change extends existing notion of synchronization scopes in LLVM to
  support arbitrary scopes expressed as target-specific strings, in addition to
  the already defined scopes (single thread, system).

  The LLVM IR and MIR syntax for expressing synchronization scopes has changed
  to use *syncscope("<scope>")*, where <scope> can be "singlethread" (this
  replaces *singlethread* keyword), or a target-specific name. As before, if
  the scope is not specified, it defaults to CrossThread/System scope.

  Implementation details:
    - Mapping from synchronization scope name/string to synchronization scope id
      is stored in LLVM context;
    - CrossThread/System and SingleThread scopes are pre-defined to efficiently
      check for known scopes without comparing strings;
    - Synchronization scope names are stored in SYNC_SCOPE_NAMES_BLOCK in
      the bitcode.

Differential Revision: https://reviews.llvm.org/D21723

llvm-svn: 307722
2017-07-11 22:23:00 +00:00
Craig Topper 95d2347ae1 [IR] Make use of Type::isPtrOrPtrVectorTy/isIntOrIntVectorTy/isFPOrFPVectorTy to shorten code. NFC
llvm-svn: 307491
2017-07-09 07:04:00 +00:00
Craig Topper 700892fd89 [IR] Rename BinaryOperator::init to AssertOK and remove argument. Replace default case in switch with llvm_unreachable since all valid opcodes are covered.
This method doesn't do any initializing. It just contains asserts. So renaming to AssertOK makes it consistent with similar instructions in other Instruction classes.

llvm-svn: 306277
2017-06-26 07:15:59 +00:00
Craig Topper d1fbb38475 [IR] Use isIntOrIntVectorTy instead of writing it out the long way. NFC
llvm-svn: 306250
2017-06-25 17:33:48 +00:00
Craig Topper c1993fa1a3 [IR] Remove getNumSuccessorsV/getSuccessorV/setSuccessorV from the TerminatorInst subclasses as much as possible now that Value has been de-virtualized
These used to be virtual methods that would enable doing the right thing with only a TerminatorInst pointer. I believe they were also acting as vtable anchors in my cases. I think the fact that they had a separate name ending in V was to allow a version without V to be called without a virtual call in a pre-C++11 final keyword world.

Where possible the base methods in TerminatorInst dispatch directly to the public methods in the classes that have the same signature. For some classes this wasn't possible so I've left private method versions that match the name and signature of the version in TerminatorInst. All versions have been moved into the class definitions since we no longer need vtable anchors here.

Differential Revision: https://reviews.llvm.org/D34011

llvm-svn: 305028
2017-06-08 23:23:08 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Reid Kleckner 5fbdd17714 [IR] Add additional addParamAttr/removeParamAttr to AttributeList API
Summary:
Fairly straightforward patch to fill in some of the holes in the
attributes API with respect to accessing parameter/argument attributes.
The patch aims to step further towards encapsulating the
idx+FirstArgIndex pattern to access these attributes to within the
AttributeList.

Patch by Daniel Neilson!

Reviewers: rnk, chandlerc, pete, javed.absar, reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33355

llvm-svn: 304329
2017-05-31 19:23:09 +00:00
Reid Kleckner 545aa4f4dd Commit AttributeList change that was supposed to be part of r303654
llvm-svn: 303656
2017-05-23 17:03:28 +00:00
Reid Kleckner 8bf67fe98f [IR] Switch AttributeList to use an array for O(1) access
Summary:
Before this change, AttributeLists stored a pair of index and
AttributeSet. This is memory efficient if most arguments do not have
attributes. However, it requires doing a search over the pairs to test
an argument or function attribute. Profiling shows that this loop was
0.76% of the time in 'opt -O2' of sqlite3.c, because LLVM constantly
tests values for nullability.

This was worth about 2.5% of mid-level optimization cycles on the
sqlite3 amalgamation. Here are the full perf results:
https://reviews.llvm.org/P7995

Here are just the before and after cycle counts:
```
$ perf stat -r 5 ./opt_before -O2 sqlite3.bc -o /dev/null
    13,274,181,184      cycles                    #    3.047 GHz                      ( +-  0.28% )
$ perf stat -r 5 ./opt_after -O2 sqlite3.bc -o /dev/null
    12,906,927,263      cycles                    #    3.043 GHz                      ( +-  0.51% )
```

This patch *does not* change the indices used to query attributes, as
requested by reviewers. Tracking whether an index is usable for array
indexing is a huge pain that affects many of the internal APIs, so it
would be good to come back later and do a cleanup to remove this
internal adjustment.

Reviewers: pete, chandlerc

Subscribers: javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D32819

llvm-svn: 303654
2017-05-23 17:01:48 +00:00
Reid Kleckner 96ab8726a3 [IR] De-virtualize ~Value to save a vptr
Summary:
Implements PR889

Removing the virtual table pointer from Value saves 1% of RSS when doing
LTO of llc on Linux. The impact on time was positive, but too noisy to
conclusively say that performance improved. Here is a link to the
spreadsheet with the original data:

https://docs.google.com/spreadsheets/d/1F4FHir0qYnV0MEp2sYYp_BuvnJgWlWPhWOwZ6LbW7W4/edit?usp=sharing

This change makes it invalid to directly delete a Value, User, or
Instruction pointer. Instead, such code can be rewritten to a null check
and a call Value::deleteValue(). Value objects tend to have their
lifetimes managed through iplist, so for the most part, this isn't a big
deal.  However, there are some places where LLVM deletes values, and
those places had to be migrated to deleteValue.  I have also created
llvm::unique_value, which has a custom deleter, so it can be used in
place of std::unique_ptr<Value>.

I had to add the "DerivedUser" Deleter escape hatch for MemorySSA, which
derives from User outside of lib/IR. Code in IR cannot include MemorySSA
headers or call the MemoryAccess object destructors without introducing
a circular dependency, so we need some level of indirection.
Unfortunately, no class derived from User may have any virtual methods,
because adding a virtual method would break User::getHungOffOperands(),
which assumes that it can find the use list immediately prior to the
User object. I've added a static_assert to the appropriate OperandTraits
templates to help people avoid this trap.

Reviewers: chandlerc, mehdi_amini, pete, dberlin, george.burgess.iv

Reviewed By: chandlerc

Subscribers: krytarowski, eraman, george.burgess.iv, mzolotukhin, Prazek, nlewycky, hans, inglorion, pcc, tejohnson, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D31261

llvm-svn: 303362
2017-05-18 17:24:10 +00:00
Eugene Zelenko d761e2c264 [IR] Fix some Clang-tidy modernize-use-using warnings; other minor fixes (NFC).
llvm-svn: 303119
2017-05-15 21:57:41 +00:00
Reid Kleckner 45a13e1b54 De-virtualize TerminatorInst successor accessors
Use the same switch technique to eliminate virtual successor accessors
from TerminatorInst. Extracted from D31261.

NFC

llvm-svn: 302827
2017-05-11 21:26:55 +00:00
Serge Guelton e38003f839 Suppress all uses of LLVM_END_WITH_NULL. NFC.
Use variadic templates instead of relying on <cstdarg> + sentinel.
This enforces better type checking and makes code more readable.

Differential Revision: https://reviews.llvm.org/D32541

llvm-svn: 302571
2017-05-09 19:31:13 +00:00
Reid Kleckner a0b45f4bfc [IR] Abstract away ArgNo+1 attribute indexing as much as possible
Summary:
Do three things to help with that:
- Add AttributeList::FirstArgIndex, which is an enumerator currently set
  to 1. It allows us to change the indexing scheme with fewer changes.
- Add addParamAttr/removeParamAttr. This just shortens addAttribute call
  sites that would otherwise need to spell out FirstArgIndex.
- Remove some attribute-specific getters and setters from Function that
  take attribute list indices.  Most of these were only used from
  BuildLibCalls, and doesNotAlias was only used to test or set if the
  return value is malloc-like.

I'm happy to split the patch, but I think they are probably easier to
review when taken together.

This patch should be NFC, but it sets the stage to change the indexing
scheme to this, which is more convenient when indexing into an array:
  0: func attrs
  1: retattrs
  2...: arg attrs

Reviewers: chandlerc, pete, javed.absar

Subscribers: david2050, llvm-commits

Differential Revision: https://reviews.llvm.org/D32811

llvm-svn: 302060
2017-05-03 18:17:31 +00:00
Reid Kleckner 6652a52e2b Use Argument::hasAttribute and AttributeList::ReturnIndex more
This eliminates many extra 'Idx' induction variables in loops over
arguments in CodeGen/ and Target/. It also reduces the number of places
where we assume that ReturnIndex is 0 and that we should add one to
argument numbers to get the corresponding attribute list index.

NFC

llvm-svn: 301666
2017-04-28 18:37:16 +00:00
Sanjay Patel 8bd52286d3 use 'auto' with 'dyn_cast' and fix formatting; NFC
llvm-svn: 300713
2017-04-19 16:22:19 +00:00
Reid Kleckner fb502d2f5e [IR] Make paramHasAttr to use arg indices instead of attr indices
This avoids the confusing 'CS.paramHasAttr(ArgNo + 1, Foo)' pattern.

Previously we were testing return value attributes with index 0, so I
introduced hasReturnAttr() for that use case.

llvm-svn: 300367
2017-04-14 20:19:02 +00:00
Chandler Carruth 927d8e610a [IR] Redesign the case iterator in SwitchInst to actually be an iterator
and to expose a handle to represent the actual case rather than having
the iterator return a reference to itself.

All of this allows the iterator to be used with common STL facilities,
standard algorithms, etc.

Doing this exposed some missing facilities in the iterator facade that
I've fixed and required some work to the actual iterator to fully
support the necessary API.

Differential Revision: https://reviews.llvm.org/D31548

llvm-svn: 300032
2017-04-12 07:27:28 +00:00
Serge Guelton 59a2d7b909 Module::getOrInsertFunction is using C-style vararg instead of variadic templates.
From a user prospective, it forces the use of an annoying nullptr to mark the end of the vararg, and there's not type checking on the arguments.
The variadic template is an obvious solution to both issues.

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299949
2017-04-11 15:01:18 +00:00
Diana Picus b050c7fbe0 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299925 because it broke the buildbots. See e.g.
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/6008

llvm-svn: 299928
2017-04-11 10:07:12 +00:00
Serge Guelton 5fd75fb72e Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

llvm-svn: 299925
2017-04-11 08:36:52 +00:00
Matt Arsenault 3c1fc768ed Allow DataLayout to specify addrspace for allocas.
LLVM makes several assumptions about address space 0. However,
alloca is presently constrained to always return this address space.
There's no real way to avoid using alloca, so without this
there is no way to opt out of these assumptions.

The problematic assumptions include:
- That the pointer size used for the stack is the same size as
  the code size pointer, which is also the maximum sized pointer.

- That 0 is an invalid, non-dereferencable pointer value.

These are problems for AMDGPU because alloca is used to
implement the private address space, which uses a 32-bit
index as the pointer value. Other pointers are 64-bit
and behave more like LLVM's notion of generic address
space. By changing the address space used for allocas,
we can change our generic pointer type to be LLVM's generic
pointer type which does have similar properties.

llvm-svn: 299888
2017-04-10 22:27:50 +00:00
Mehdi Amini db11fdfda5 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299699, the examples needs to be updated.

llvm-svn: 299702
2017-04-06 20:23:57 +00:00
Mehdi Amini 579540a8f7 Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

Patch by: Serge Guelton <serge.guelton@telecom-bretagne.eu>

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299699
2017-04-06 20:09:31 +00:00
Chandler Carruth 0d256c0f5d [IR] Make SwitchInst::CaseIt almost a normal iterator.
This moves it to the iterator facade utilities giving it full random
access semantics, etc. It can also now be used with standard algorithms
like std::all_of and std::any_of and range adaptors like llvm::reverse.

Also make the semantics of iterating match what every other iterator
uses and forbid decrementing past the begin iterator. This was used as
a hacky way to work around iterator invalidation. However, every
instance trying to do this failed to actually avoid touching invalid
iterators despite the clear documentation that the removed and all
subsequent iterators become invalid including the end iterator. So I've
added a return of the next iterator to removeCase and rewritten the
loops that were doing this to correctly follow the iterator pattern of
either incremneting or removing and assigning fresh values to the
iterator and the end.

In one case we were trying to go backwards to make this cleaner but it
doesn't actually work. I've made that code match the code we use
everywhere else to remove cases as we iterate. This changes the order of
cases in one test output and I moved that test to CHECK-DAG so it
wouldn't care -- the order isn't semantically meaningful anyways.

llvm-svn: 298791
2017-03-26 02:49:23 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Sanjay Patel 4ce99d4d24 fix comment formatting; NFC
llvm-svn: 287127
2016-11-16 18:09:44 +00:00
Peter Collingbourne 9d5fd4db81 IR: Change the Type::get{Array,Vector,Pointer}ElementType() functions to perform the correct type assertion.
Previously we were only asserting that the type was a sequential type.

llvm-svn: 286749
2016-11-13 06:58:45 +00:00
Sanjoy Das 1f7b813e2b Remove duplicated code; NFC
ICmpInst::makeConstantRange does exactly the same thing as
ConstantRange::makeExactICmpRegion.

llvm-svn: 283059
2016-10-02 00:09:57 +00:00
Amaury Sechet 5f04d819a5 Rationalise the attribute getter/setter methods on Function and CallSite.
Summary:
While woring on mapping attributes in the C API, it clearly appeared that the recent changes in the API on the C++ side left Function and Call/Invoke with an attribute API that grew in an ad hoc manner. This makes it difficult to work with it, because one doesn't know which overloads exists and which do not.

Make sure that getter/setter function exists for both enum and string version. Remove inconsistent getter/setter, unless they have many callsites.

This should make it easier to work with attributes in the future.

This doesn't change how attribute works.

Reviewers: bkramer, whitequark, mehdi_amini, void

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21514

llvm-svn: 281019
2016-09-09 04:50:38 +00:00
Sanjay Patel bd51c164d9 fix documentation comments; NFC
llvm-svn: 280489
2016-09-02 15:43:25 +00:00
Xinliang David Li dc49140b44 [Profile] refactor meta data copying/swapping code
Differential Revision: http://reviews.llvm.org/D23619

llvm-svn: 279523
2016-08-23 15:39:03 +00:00
Tim Northover de3aea0412 GlobalISel: support irtranslation of icmp instructions.
llvm-svn: 278969
2016-08-17 20:25:25 +00:00
Hal Finkel e87ad547ef Add getReturnedArgOperand to Call/InvokeInst, CallSite
In order to make the optimizer smarter about using the 'returned' argument
attribute (generally, but motivated by my llvm.noalias intrinsic work), add a
utility function to Call/InvokeInst, and CallSite, to make it easy to get the
returned call argument (when one exists).

P.S. There is already an unfortunate amount of code duplication between
CallInst and InvokeInst, and this adds to it. We should probably clean that up
separately.

Differential Revision: http://reviews.llvm.org/D22204

llvm-svn: 275031
2016-07-10 23:01:32 +00:00
Amaury Sechet 6100adfeb5 Add support for string attributes in the C API.
Summary: As per title. This completes the C API Attribute support.

Reviewers: Wallbraker, whitequark, echristo, rafael, jyknight

Subscribers: mehdi_amini

Differential Revision: http://reviews.llvm.org/D21365

llvm-svn: 272811
2016-06-15 17:50:39 +00:00
Amaury Sechet a65a237805 Add support for callsite in the new C API for attributes
Summary: The second consumer of attributes.

Reviewers: Wallbraker, whitequark, echristo, rafael, jyknight

Subscribers: mehdi_amini

Differential Revision: http://reviews.llvm.org/D21266

llvm-svn: 272754
2016-06-15 05:14:29 +00:00
Amaury Sechet 392638d7b1 Make sure attribute kind and attributes are named respectively Kind and Attr consistently. Historically they used to be the same the terminology is very confused in the codebase. NFC.
llvm-svn: 272704
2016-06-14 20:27:35 +00:00
David Majnemer fadc6db036 [GlobalOpt] Propagate operand bundles
We neglected to transfer operand bundles for some transforms.  These
were found via inspection, I'll try to come up with some test cases.

llvm-svn: 268011
2016-04-29 08:07:22 +00:00
Sanjay Patel d66607bd8c [CodeGenPrepare] use branch weight metadata to decide if a select should be turned into a branch
This is part of solving PR27344:
https://llvm.org/bugs/show_bug.cgi?id=27344

CGP should undo the SimplifyCFG transform for the same reason that earlier patches have used this
same mechanism: it's possible that passes between SimplifyCFG and CGP may be able to optimize the
IR further with a select in place.

For the TLI hook default, >99% taken or not taken is chosen as the default threshold for a highly
predictable branch. Even the most limited HW branch predictors will be correct on this branch almost
all the time, so even a massive mispredict penalty perf loss would be overcome by the win from all
the times the branch was predicted correctly.

As a follow-up, we could make the default target hook less conservative by using the SchedMachineModel's
MispredictPenalty. Or we could just let targets override the default by implementing the hook with that
and other target-specific options. Note that trying to statically determine mispredict rates for 
close-to-balanced profile weight data is generally impossible if the HW is sufficiently advanced. Ie, 
50/50 taken/not-taken might still be 100% predictable.

Finally, note that this patch as-is will not solve PR27344 because the current __builtin_unpredictable()
branch weight default values are 4 and 64. A proposal to change that is in D19435.

Differential Revision: http://reviews.llvm.org/D19488

llvm-svn: 267572
2016-04-26 17:11:17 +00:00
Sanjay Patel 82059090d3 Add check for "branch_weights" with prof metadata
While we're here, fix the comment and variable names to make it
clear that these are raw weights, not percentages.

llvm-svn: 267491
2016-04-25 23:15:16 +00:00
Chad Rosier 3d75f8ce9e Typo. NFC.
llvm-svn: 267399
2016-04-25 13:25:14 +00:00
Sanjay Patel dc88bd6e1f replace duplicated static functions for profile metadata access with BranchInst member function; NFCI
llvm-svn: 267295
2016-04-23 20:01:22 +00:00
Chad Rosier 1a60159064 [SimplifyCFG] Add final missing implications to isImpliedTrueByMatchingCmp.
Summary: eq imply [u|s]ge and [u|s]le are true.

Remove redundant logic by implementing isImpliedFalseByMatchingCmp(Pred1, Pred2)
as isImpliedTrueByMatchingCmp(Pred1, getInversePredicate(Pred2)).

llvm-svn: 267177
2016-04-22 17:57:34 +00:00
Chad Rosier 3456cb5672 [SimplifyCFG] Add missing implications to isImpliedTrueByMatchingCmp.
Summary: [u|s]gt and [u|s]lt imply [u|s]ge and [u|s]le are true, respectively.
I've simplified the existing tests and added additional tests to cover the new
cases mentioned above.  I've also added tests for all the cases where the
first compare doesn't imply anything about the second compare.

llvm-svn: 267171
2016-04-22 17:14:12 +00:00
David Majnemer 9554c1339c [EarlyCSE] Take the intersection of flags on instructions
EarlyCSE had inconsistent behavior with regards to flag'd instructions:
- In some cases, it would pessimize if the available instruction had
  different flags by not performing CSE.
- In other cases, it would miscompile if it replaced an instruction
  which had no flags with an instruction which has flags.

Fix this by being more consistent with our flag handling by utilizing
andIRFlags.

llvm-svn: 267111
2016-04-22 06:37:45 +00:00
Amaury Sechet 1a0e0978b4 Add utility function to manipulate attributes on CallSite. NFC
Summary: As per title. This will help work on the C API.

Reviewers: Wallbraker, whitequark, joker.eph, echristo, rafael

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19173

llvm-svn: 267057
2016-04-21 21:29:10 +00:00
Chad Rosier 99bc480bc3 Address Philip's post-commit feedback for r266987. NFC.
llvm-svn: 266998
2016-04-21 16:18:02 +00:00
Chad Rosier af83e40dee Refactor implied condition logic from ValueTracking directly into CmpInst. NFC.
Differential Revision: http://reviews.llvm.org/D19330

llvm-svn: 266987
2016-04-21 14:04:54 +00:00
Nicolai Haehnle 13d90f324c [DivergenceAnalysis] Treat PHI with incoming undef as constant
Summary:
If a PHI has an incoming undef, we can pretend that it is equal to one
non-undef, non-self incoming value.

This is particularly relevant in combination with the StructurizeCFG
pass, which introduces PHI nodes with undefs. Previously, this lead to
branch conditions that were uniform before StructurizeCFG to become
non-uniform afterwards, which confused the SIAnnotateControlFlow
pass.

This fixes a crash when Mesa radeonsi compiles a shader from
dEQP-GLES3.functional.shaders.switch.switch_in_for_loop_dynamic_vertex

Reviewers: arsenm, tstellarAMD, jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19013

llvm-svn: 266347
2016-04-14 17:42:47 +00:00
JF Bastien 800f87a871 NFC: make AtomicOrdering an enum class
Summary:
In the context of http://wg21.link/lwg2445 C++ uses the concept of
'stronger' ordering but doesn't define it properly. This should be fixed
in C++17 barring a small question that's still open.

The code currently plays fast and loose with the AtomicOrdering
enum. Using an enum class is one step towards tightening things. I later
also want to tighten related enums, such as clang's
AtomicOrderingKind (which should be shared with LLVM as a 'C++ ABI'
enum).

This change touches a few lines of code which can be improved later, I'd
like to keep it as NFC for now as it's already quite complex. I have
related changes for clang.

As a follow-up I'll add:
  bool operator<(AtomicOrdering, AtomicOrdering) = delete;
  bool operator>(AtomicOrdering, AtomicOrdering) = delete;
  bool operator<=(AtomicOrdering, AtomicOrdering) = delete;
  bool operator>=(AtomicOrdering, AtomicOrdering) = delete;
This is separate so that clang and LLVM changes don't need to be in sync.

Reviewers: jyknight, reames

Subscribers: jyknight, llvm-commits

Differential Revision: http://reviews.llvm.org/D18775

llvm-svn: 265602
2016-04-06 21:19:33 +00:00