Commit Graph

70 Commits

Author SHA1 Message Date
Benjamin Kramer 81f385b0c6 Make dropTriviallyDeadConstantArrays not quadratic
Only look at the operands of dead constant arrays instead of all
constant arrays again.
2020-01-21 16:06:46 +01:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Vedant Kumar 69ee62cef8 [LLVMContext] Detecting leaked instructions with metadata
When instructions with metadata are accidentally leaked, the result is a
difficult-to-find memory corruption in ~LLVMContextImpl that leads to
random crashes.

Patch by Arvīds Kokins!

llvm-svn: 336010
2018-06-29 20:13:13 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Fedor Sergeev d29884c7e6 allow custom OptBisect classes set to LLVMContext
This patch introduces a way to set custom OptPassGate instances to LLVMContext.
A new instance field OptBisector and a new method setOptBisect() are added
to the LLVMContext classes. These changes allow to set a custom OptBisect class
that can make its own decisions on skipping optional passes.

Another important feature of this change is ability to set different instances
of OptPassGate to different LLVMContexts. So the different contexts can be used
independently in several compiling threads of one process.

One unit test is added.

Patch by Yevgeny Rouban.

Reviewers: andrew.w.kaylor, fedor.sergeev, vsk, dberlin, Eugene.Zelenko, reames, skatkov
Reviewed By: andrew.w.kaylor, fedor.sergeev
Differential Revision: https://reviews.llvm.org/D44464

llvm-svn: 329267
2018-04-05 10:29:37 +00:00
Fedor Sergeev 98014e433f [NFC] OptPassGate extracted from OptBisect
Summary:
This is an NFC refactoring of the OptBisect class to split it into an optional pass gate interface used by LLVMContext and the Optional Pass Bisector (OptBisect) used for debugging of optional passes.

This refactoring is needed for D44464, which introduces setOptPassGate() method to allow implementations other than OptBisect.

Patch by Yevgeny Rouban.

Reviewers: andrew.w.kaylor, fedor.sergeev, vsk, dberlin, Eugene.Zelenko, reames, skatkov
Reviewed By: fedor.sergeev
Differential Revision: https://reviews.llvm.org/D44821

llvm-svn: 328637
2018-03-27 16:57:20 +00:00
Vivek Pandya b5ab895e2a This patch fixes https://bugs.llvm.org/show_bug.cgi?id=32352
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled. 
However LLVM-C API users can still provide callback function for diagnostic handler.

llvm-svn: 313390
2017-09-15 20:10:09 +00:00
Vivek Pandya df8598dcc4 This reverts r313381
llvm-svn: 313387
2017-09-15 19:53:54 +00:00
Vivek Pandya 00d887447b This patch fixes https://bugs.llvm.org/show_bug.cgi?id=32352
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled. 
However LLVM-C API users can still provide callback function for diagnostic handler.

llvm-svn: 313382
2017-09-15 19:30:59 +00:00
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
Eugene Zelenko de6cce2236 [IR] Fix some Clang-tidy modernize-use-using warnings; other minor fixes (NFC).
llvm-svn: 305755
2017-06-19 22:05:08 +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
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
Justin Lebar 611c5c225a Use unique_ptr in LLVMContextImpl's constant maps.
Reviewers: timshen

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D25419

llvm-svn: 283767
2016-10-10 16:26:13 +00:00
Adam Nemet aad816083e [OptRemark,LDist] RFC: Add hotness attribute
Summary:
This is the first set of changes implementing the RFC from
http://thread.gmane.org/gmane.comp.compilers.llvm.devel/98334

This is a cross-sectional patch; rather than implementing the hotness
attribute for all optimization remarks and all passes in a patch set, it
implements it for the 'missed-optimization' remark for Loop
Distribution.  My goal is to shake out the design issues before scaling
it up to other types and passes.

Hotness is computed as an integer as the multiplication of the block
frequency with the function entry count.  It's only printed in opt
currently since clang prints the diagnostic fields directly.  E.g.:

  remark: /tmp/t.c:3:3: loop not distributed: use -Rpass-analysis=loop-distribute for more info (hotness: 300)

A new API added is similar to emitOptimizationRemarkMissed.  The
difference is that it additionally takes a code region that the
diagnostic corresponds to.  From this, hotness is computed using BFI.
The new API is exposed via an analysis pass so that it can be made
dependent on LazyBFI.  (Thanks to Hal for the analysis pass idea.)

This feature can all be enabled by setDiagnosticHotnessRequested in the
LLVM context.  If this is off, LazyBFI is not calculated (D22141) so
there should be no overhead.

A new command-line option is added to turn this on in opt.

My plan is to switch all user of emitOptimizationRemark* to use this
module instead.

Reviewers: hfinkel

Subscribers: rcox2, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D21771

llvm-svn: 275583
2016-07-15 17:23:20 +00:00
Benjamin Kramer af28e7d6fa Apply clang-tidy's modernize-loop-convert to most of lib/IR.
Only minor manual fixes. No functionality change intended.

llvm-svn: 273813
2016-06-26 14:10:56 +00:00
Andrew Kaylor aa641a5171 Re-commit optimization bisect support (r267022) without new pass manager support.
The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231
2016-04-22 22:06:11 +00:00
Vedant Kumar 6013f45f92 Revert "Initial implementation of optimization bisect support."
This reverts commit r267022, due to an ASan failure:

  http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549

llvm-svn: 267115
2016-04-22 06:51:37 +00:00
Andrew Kaylor f0f279291c Initial implementation of optimization bisect support.
This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.

The bisection is enabled using a new command line option (-opt-bisect-limit).  Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit.  A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.

The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check.  Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute.  A new function call has been added for module and SCC passes that behaves in a similar way.

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267022
2016-04-21 17:58:54 +00:00
Duncan P. N. Exon Smith ef06d445e0 IR: Use DenseSet instead of DenseMap for ConstantUniqueMap; NFC
Use a DenseSet instead of a DenseMap for constants in LLVMContextImpl.
Last time I looked at this was some time before r223588, when
DenseSet<V> had no advantage over DenseMap<V,char>.  After r223588,
there's a 50% memory savings.

This is all mechanical.  There were little bits of missing API from
DenseSet so I added the trivial implementations:

  - iterator::operator++(int)
  - template <class LookupKeyT> insert_as(ValueTy, LookupKeyT)

There should be no functionality change, just reduced memory consumption
(this wasn't on a profile or anything; just a cleanup I stumbled on).

llvm-svn: 265577
2016-04-06 17:56:08 +00:00
Duncan P. N. Exon Smith f3d08ef59a IR: Stop explicitly clearing the MDStringCache
The MDStringCache doesn't need to be explicitly cleared before
destruction.  The destructor handles it at least as efficiently.

llvm-svn: 265576
2016-04-06 17:56:05 +00:00
David Majnemer 2dd41c5d42 [IR] Manage TheNoneToken with a std::unique_ptr
Hopefully, this will make the sanitizer build bots happy.

llvm-svn: 253248
2015-11-16 20:55:57 +00:00
David Majnemer f0f224d12d [IR] Add support for empty tokens
When working with tokens, it is often the case that one has instructions
which consume a token and produce a new token.  Currently, we have no
mechanism to represent an initial token state.

Instead, we can create a notional "empty token" by inventing a new
constant which captures the semantics we would like.  This new constant
is called ConstantTokenNone and is written textually as "token none".

Differential Revision: http://reviews.llvm.org/D14581

llvm-svn: 252811
2015-11-11 21:57:16 +00:00
Sanjoy Das 9303c24650 [IR] Add operand bundles to CallInst and InvokeInst.
Summary:
This change teaches `CallInst`s and `InvokeInst`s to maintain a set of
operand bundles as part of its operands.  `CallInst`s and `InvokeInst`s
with operand bundles co-allocate some space before their `Use` array to
hold meta information about which of its operands are part of an operand
bundle.

The strings corresponding to the bundle tags are interned into
`LLVMContextImpl::BundleTagCache`

This change does not include any parsing / bitcode support.  That's the
next change.

Depends on D12455.

Reviewers: reames, chandlerc, majnemer, dexonsmith, kmod, JosephTremoulet, rnk, bogner

Subscribers: MatzeB, sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D12456

llvm-svn: 248527
2015-09-24 19:14:18 +00:00
David Majnemer b611e3f50e [IR] Add token types
This introduces the basic functionality to support "token types".
The motivation stems from the need to perform operations on a Value
whose provenance cannot be obscured.

There are several applications for such a type but my immediate
motivation stems from WinEH.  Our personality routine enforces a
single-entry - single-exit regime for cleanups.  After several rounds of
optimizations, we may be left with a terminator whose "cleanup-entry
block" is not entirely clear because control flow has merged two
cleanups together.  We have experimented with using labels as operands
inside of instructions which are not terminators to indicate where we
came from but found that LLVM does not expect such exotic uses of
BasicBlocks.

Instead, we can use this new type to clearly associate the "entry point"
and "exit point" of our cleanup.  This is done by having the cleanuppad
yield a Token and consuming it at the cleanupret.
The token type makes it impossible to obscure or otherwise hide the
Value, making it trivial to track the relationship between the two
points.

What is the burden to the optimizer?  Well, it turns out we have already
paid down this cost by accepting that there are certain calls that we
are not permitted to duplicate, optimizations have to watch out for
such instructions anyway.  There are additional places in the optimizer
that we will probably have to update but early examination has given me
the impression that this will not be heroic.

Differential Revision: http://reviews.llvm.org/D11861

llvm-svn: 245029
2015-08-14 05:09:07 +00:00
Duncan P. N. Exon Smith 55ca964e94 DI: Disallow uniquable DICompileUnits
Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode.  This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.

Almost all the testcases were updated with this script:

    git grep -e '= !DICompileUnit' -l -- test |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'

I imagine something similar should work for out-of-tree testcases.

llvm-svn: 243885
2015-08-03 17:26:41 +00:00
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
Kit Barton 7291802533 Add the i128 builtin type to LLVM.
The i128 type is needed as a builtin type in order to support the v1i128 vector
type. The PowerPC ABI requires that the i128 and v1i128 types are handled
differently when passed as parameters to functions (i128 is passed in pairs of
GPRs, v1i128 is passed in a single vector register). 

http://reviews.llvm.org/D8564

llvm-svn: 235196
2015-04-17 15:32:15 +00:00
Philip Reames 56a03938f7 Revert GCStrategy ownership changes
This change reverts the interesting parts of 226311 (and 227046).  This change introduced two problems, and I've been convinced that an alternate approach is preferrable anyways.

The bugs were:
- Registery appears to require all users be within the same linkage unit.  After this change, asking for "statepoint-example" in Transform/ would sometimes get you nullptr, whereas asking the same question in CodeGen would return the right GCStrategy.  The correct long term fix is to get rid of the utter hack which is Registry, but I don't have time for that right now.  227046 appears to have been an attempt to fix this, but I don't believe it does so completely.
- GCMetadataPrinter::finishAssembly was being called more than once per GCStrategy.  Each Strategy was being added to the GCModuleInfo multiple times.

Once I get time again, I'm going to split GCModuleInfo into the gc.root specific part and a GCStrategy owning Analysis pass.  I'm probably also going to kill off the Registry.  Once that's done, I'll move the new GCStrategyAnalysis and all built in GCStrategies into Analysis.  (As original suggested by Chandler.)  This will accomplish my original goal of being able to access GCStrategy from Transform/  without adding all of the builtin GCs to IR/.  

llvm-svn: 227109
2015-01-26 18:26:35 +00:00
Benjamin Kramer cb36becbeb Remove dead leak detector parts that fell out of use in r224703.
llvm-svn: 226867
2015-01-22 21:43:01 +00:00
Manman Ren dab999d54f [llvm link] Destroy ConstantArrays in LLVMContext if they are not used.
ConstantArrays constructed during linking can cause quadratic memory
explosion. An example is the ConstantArrays constructed when linking in
GlobalVariables with appending linkage.

Releasing all unused constants can cause a 20% LTO compile-time
slowdown for a large application. So this commit releases unused ConstantArrays
only.

rdar://19040716. It reduces memory footprint from 20+G to 6+G.

llvm-svn: 226592
2015-01-20 19:24:59 +00:00
Duncan P. N. Exon Smith 408f5a25fa IR: Delete GenericDwarfNode during teardown
Fix a leak in `LLVMContextImpl` teardown that the leak sanitizer tracked
down [1].  I've just switched to automatic dispatch here (since I'll
inevitably forget again with the next class).

[1]: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/811/steps/check-llvm%20asan/logs/stdio

llvm-svn: 226536
2015-01-20 01:18:32 +00:00
Duncan P. N. Exon Smith fed199a758 IR: Introduce GenericDwarfNode
As part of PR22235, introduce `DwarfNode` and `GenericDwarfNode`.  The
former is a metadata node with a DWARF tag.  The latter matches our
current (generic) schema of a header with string (and stringified
integer) data and an arbitrary number of operands.

This doesn't move it into place yet; that change will require a large
number of testcase updates.

llvm-svn: 226529
2015-01-20 00:01:43 +00:00
Duncan P. N. Exon Smith 2bc00f4a38 IR: Merge UniquableMDNode back into MDNode, NFC
As pointed out in r226501, the distinction between `MDNode` and
`UniquableMDNode` is confusing.  When we need subclasses of `MDNode`
that don't use all its functionality it might make sense to break it
apart again, but until then this makes the code clearer.

llvm-svn: 226520
2015-01-19 23:13:14 +00:00
Duncan P. N. Exon Smith 93e983e707 IR: Extract MDNodeOpsKey, NFC
Make the MDTuple operand hashing logic reusable.

llvm-svn: 226519
2015-01-19 22:53:18 +00:00
Philip Reames 2b45395876 Move ownership of GCStrategy objects to LLVMContext
Note: This change ended up being slightly more controversial than expected.  Chandler has tentatively okayed this for the moment, but I may be revisiting this in the near future after we settle some high level questions.

Rather than have the GCStrategy object owned by the GCModuleInfo - which is an immutable analysis pass used mainly by gc.root - have it be owned by the LLVMContext. This simplifies the ownership logic (i.e. can you have two instances of the same strategy at once?), but more importantly, allows us to access the GCStrategy in the middle end optimizer. To this end, I add an accessor through Function which becomes the canonical way to get at a GCStrategy instance.

In the near future, this will allows me to move some of the checks from http://reviews.llvm.org/D6808 into the Verifier itself, and to introduce optimization legality predicates for some of the recent additions to InstCombine. (These will follow as separate changes.)

Differential Revision: http://reviews.llvm.org/D6811

llvm-svn: 226311
2015-01-16 20:07:33 +00:00
Duncan P. N. Exon Smith e16d587515 IR: Drop metadata references more aggressively during teardown
Sometimes teardown happens before the debug info graph is complete
(e.g., when clang throws an error).  In that case, `MDNode`s will still
have RAUW, so deleting constants that the `MDNode`s point at will be
relatively expensive -- it'll cause re-uniquing all up the chain (what
I've been referring to as "teardown madness").

So, drop references *before* deleting constants.  We need to drop a few
more references now: the metadata side of the metadata/value bridges
needs to be dropped off the cliff along with the rest of it (previously,
the bridges were cleaned before we did anything with the `MDNode`s).

There's no real functionality change here -- state before and after
`LLVMContextImpl::~LLVMContextImpl()` is unchanged -- so no testcase.

llvm-svn: 226044
2015-01-14 21:58:17 +00:00
Duncan P. N. Exon Smith de03ff5721 IR: Add MDLocation class
Add a new subclass of `UniquableMDNode`, `MDLocation`.  This will be the
IR version of `DebugLoc` and `DILocation`.  The goal is to rename this
to `DILocation` once the IR classes supersede the `DI`-prefixed
wrappers.

This isn't used anywhere yet.  Part of PR21433.

llvm-svn: 225824
2015-01-13 20:44:56 +00:00
Duncan P. N. Exon Smith bf68e80d06 IR: Prepare for a new UniquableMDNode subclass, NFC
Add generic dispatch for the parts of `UniquableMDNode` that cast to
`MDTuple`.  This makes adding other subclasses (like PR21433's
`MDLocation`) easier.

llvm-svn: 225697
2015-01-12 20:56:33 +00:00
Duncan P. N. Exon Smith 6b1f4659f9 IR: Stop erasing MDNodes from uniquing sets during teardown
Stop erasing `MDNode`s from the uniquing sets in `LLVMContextImpl`
during teardown (in particular, during
`UniquableMDNode::~UniquableMDNode()`).  Although it's currently
feasible, there isn't any clear benefit and it may not be feasible for
other subclasses (which don't explicitly store the lookup hash).

llvm-svn: 225696
2015-01-12 20:50:25 +00:00
Duncan P. N. Exon Smith 118632dbf6 IR: Split GenericMDNode into MDTuple and UniquableMDNode
Split `GenericMDNode` into two classes (with more descriptive names).

  - `UniquableMDNode` will be a common subclass for `MDNode`s that are
    sometimes uniqued like constants, and sometimes 'distinct'.

    This class gets the (short-lived) RAUW support and related API.

  - `MDTuple` is the basic tuple that has always been returned by
    `MDNode::get()`.  This is as opposed to more specific nodes to be
    added soon, which have additional fields, custom assembly syntax,
    and extra semantics.

    This class gets the hash-related logic, since other sublcasses of
    `UniquableMDNode` may need to hash based on other fields.

To keep this diff from getting too big, I've added casts to `MDTuple`
that won't really scale as new subclasses of `UniquableMDNode` are
added, but I'll clean those up incrementally.

(No functionality change intended.)

llvm-svn: 225682
2015-01-12 20:09:34 +00:00
Duncan P. N. Exon Smith 5bf8fef580 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

llvm-svn: 223802
2014-12-09 18:38:53 +00:00
David Blaikie cb2818fa76 Revert "unique_ptrify LLVMContextImpl::CAZConstants"
Missed the complexities of how these elements are destroyed.

This reverts commit r222714.

llvm-svn: 222715
2014-11-25 02:26:22 +00:00
David Blaikie 899b85a556 unique_ptrify LLVMContextImpl::CAZConstants
llvm-svn: 222714
2014-11-25 02:13:54 +00:00
Duncan P. N. Exon Smith c23610b1e4 IR: Move MDNode operands from the back to the front
Having the operands at the back prevents subclasses from safely adding
fields.  Move them to the front.

Instead of replicating the custom `malloc()`, `free()` and `DestroyFlag`
logic that was there before, overload `new` and `delete`.

I added calls to a new `GenericMDNode::dropAllReferences()` in
`LLVMContextImpl::~LLVMContextImpl()`.  There's a maze of callbacks
happening during teardown, and this resolves them before we enter
the destructors.

Part of PR21532.

llvm-svn: 222211
2014-11-18 01:56:14 +00:00
Duncan P. N. Exon Smith 50846f80ac IR: Split MDNode into GenericMDNode and MDNodeFwdDecl
Split `MDNode` into two classes:

  - `GenericMDNode`, which is uniquable (and for now, always starts
    uniqued).  Once `Metadata` is split from the `Value` hierarchy, this
    class will lose the ability to RAUW itself.

  - `MDNodeFwdDecl`, which is used for the "temporary" interface, is
    never uniqued, and isn't managed by `LLVMContext` at all.

I've left most of the guts in `MDNode` for now, but I'll incrementally
move things to the right places (or delete the functionality, as
appropriate).

Part of PR21532.

llvm-svn: 222205
2014-11-18 00:37:17 +00:00
Duncan P. N. Exon Smith f39c3b8108 IR: Simplify uniquing for MDNode
Change uniquing from a `FoldingSet` to a `DenseSet` with custom
`DenseMapInfo`.  Unfortunately, this doesn't save any memory, since
`DenseSet<T>` is a simple wrapper for `DenseMap<T, char>`, but I'll come
back to fix that later.

I used the name `GenericDenseMapInfo` to the custom `DenseMapInfo` since
I'll be splitting `MDNode` into two classes soon: `MDNodeFwdDecl` for
temporaries, and `GenericMDNode` for everything else.

I also added a non-debug-info reduced version of a type-uniquing test
that started failing on an earlier draft of this patch.

Part of PR21532.

llvm-svn: 222191
2014-11-17 23:28:21 +00:00
Duncan P. N. Exon Smith f17e740157 IR: Rewrite uniquing and creation of MDString
Stop using `Value::getName()` to get the string behind an `MDString`.
Switch to `StringMapEntry<MDString>` so that we can find the string by
its coallocation.

This is part of PR21532.

llvm-svn: 221960
2014-11-14 01:17:09 +00:00