Commit Graph

88 Commits

Author SHA1 Message Date
Vedant Kumar 1ab5ea564f [Function] Clean up {prefix,prologue} data routines (NFC)
Factor out some common code used to get+set function prefix/prologue
data. This may come in handy if we ever decide to store personality
functions in the same way we store prefix/prologue data.

Differential Revision: http://reviews.llvm.org/D13120

Reviewed-by: bogner
llvm-svn: 249460
2015-10-06 20:31:57 +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
Duncan P. N. Exon Smith ed013cd221 DI: Remove DW_TAG_arg_variable and DW_TAG_auto_variable
Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.

Most of the testcase updates were generated by the following sed script:

    find test/ -name "*.ll" -o -name "*.mir" |
    xargs grep -l 'DILocalVariable' |
    xargs sed -i '' \
      -e 's/tag: DW_TAG_arg_variable, //' \
      -e 's/tag: DW_TAG_auto_variable, //'

There were only a handful of tests in `test/Assembly` that I needed to
update by hand.

(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`.  I've added a FIXME to that effect.)

llvm-svn: 243774
2015-07-31 18:58:39 +00:00
Adrian Prantl ab1243fe6c Add a DIModule metadata node to the IR.
It is meant to be used to record modules @imported by the current
compile unit, so a debugger an import the same modules to replicate this
environment before dropping into the expression evaluator.

DIModule is a sibling to DINamespace and behaves quite similarly.
In addition to the name of the module it also records the module
configuration details that are necessary to uniquely identify the module.
This includes the configuration macros (e.g., -DNDEBUG), the include path
where the module.map file is to be found, and the isysroot.

The idea is that the backend will turn this into a DW_TAG_module.

http://reviews.llvm.org/D9614
rdar://problem/20965932

llvm-svn: 241017
2015-06-29 23:03:47 +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
Owen Anderson 7349ab9385 Move the name pointer out of Value into a map that lives on the
LLVMContext.  Production builds of clang do not set names on most
Value's, so this is wasted space on almost all subclasses of Value.
This reduces the size of all Value subclasses by 8 bytes on 64 bit
hosts.

The one tricky part of this change is averting compile time regression
by keeping Value::hasName() fast.  This required stealing bits out of
NumOperands.

With this change, peak memory usage on verify-uselistorder-nodbg.lto.bc
is decreased by approximately 2.3% (~3MB absolute on my machine).

llvm-svn: 238791
2015-06-01 22:24:01 +00:00
Adrian Prantl 1f599f9f65 IR / debug info: Add a DWOId field to DICompileUnit,
so DWARF skeleton CUs can be expression in IR. A skeleton CU is a
(typically empty) DW_TAG_compile_unit that has a DW_AT_(GNU)_dwo_name and
a DW_AT_(GNU)_dwo_id attribute. It is used to refer to external debug info.

This is a prerequisite for clang module debugging as discussed in
http://lists.cs.uiuc.edu/pipermail/cfe-dev/2014-November/040076.html.
In order to refer to external types stored in split DWARF (dwo) objects,
such as clang modules, we need to emit skeleton CUs, which identify the
dwarf object (i.e., the clang module) by filename (the SplitDebugFilename)
and a hash value, the dwo_id.

This patch only contains the IR changes. The idea is that a CUs with a
non-zero dwo_id field will be emitted together with a DW_AT_GNU_dwo_name
and DW_AT_GNU_dwo_id attribute.

http://reviews.llvm.org/D9488
rdar://problem/20091852

llvm-svn: 237949
2015-05-21 20:37:30 +00:00
Pete Cooper a7c0c18c4d Store intrinsic ID by value in Function instead of a string lookup. NFC.
On 64-bit targets, Function has 4-bytes of padding in its struct layout.

This uses the space for the intrinsic ID. It is set and recalculated whenever the function name is set.  This is similar to the current behavior which clears the function from the intrinsic ID cache when its renamed.

The intrinsic cache itself is removed as the only purpose was to speedup calls to getIntrinsicID() which now just reading the new field in the struct.

Reviewed by Duncan.  http://reviews.llvm.org/D9836

llvm-svn: 237642
2015-05-19 00:24:26 +00:00
Duncan P. N. Exon Smith a9308c49ef IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one.  It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs.  YMMV of
course.

Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py.  I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three.  It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).

Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.

llvm-svn: 236120
2015-04-29 16:38:44 +00:00
Duncan P. N. Exon Smith e2510cdfe8 IR: Add Function metadata attachments
Add IR support for `Metadata` attachments.  Assembly and bitcode support
will follow shortly, but for now we just have unit tests.  This is part
of PR23340.

llvm-svn: 235783
2015-04-24 21:51:02 +00:00
Duncan P. N. Exon Smith cbc28dc549 IR: Extract set logic from Instruction attachments, NFC
Extract the set logic for metadata attachments from `Instruction` so it
can be reused for `Function` (PR23340).

This data structure makes a `SmallVector<>` look (a little) like a map,
just doing the bare minimum to support the `Instruction` (and soon,
`Function`) metadata API.

llvm-svn: 235769
2015-04-24 20:36:25 +00:00
Duncan P. N. Exon Smith 14a384bee6 IR: Remove MDMapTy and MDPairTy typedefs, NFC
Remove some typedefs in preparation for factoring out attachment logic
from `Instruction`.

llvm-svn: 235764
2015-04-24 20:19:13 +00:00
Duncan P. N. Exon Smith 391fc56ffd IR: Rename LLVMContextImpl::MetadataStore to InstructionMetadata
Rename `MetadataStore` to the more explicit `InstructionMetadata`.  This
will make room for `FunctionMetadata` (start of PR23340).

llvm-svn: 235763
2015-04-24 20:16:42 +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
Duncan P. N. Exon Smith 62e0f454a0 DebugInfo: Remove 'inlinedAt:' field from MDLocalVariable
Remove 'inlinedAt:' from MDLocalVariable.  Besides saving some memory
(variables with it seem to be single largest `Metadata` contributer to
memory usage right now in -g -flto builds), this stops optimization and
backend passes from having to change local variables.

The 'inlinedAt:' field was used by the backend in two ways:

 1. To tell the backend whether and into what a variable was inlined.
 2. To create a unique id for each inlined variable.

Instead, rely on the 'inlinedAt:' field of the intrinsic's `!dbg`
attachment, and change the DWARF backend to use a typedef called
`InlinedVariable` which is `std::pair<MDLocalVariable*, MDLocation*>`.
This `DebugLoc` is already passed reliably through the backend (as
verified by r234021).

This commit removes the check from r234021, but I added a new check
(that will survive) in r235048, and changed the `DIBuilder` API in
r235041 to require a `!dbg` attachment whose 'scope:` is in the same
`MDSubprogram` as the variable's.

If this breaks your out-of-tree testcases, perhaps the script I used
(mdlocalvariable-drop-inlinedat.sh) will help; I'll attach it to PR22778
in a moment.

llvm-svn: 235050
2015-04-15 22:29:27 +00:00
Duncan P. N. Exon Smith 5dcf621c8a IR: Rename MDSubrange::getLo() to getLowerBound()
During initial review, the `lo:` field was renamed to `lowerBound:`.
Make the same change to the C++ API.

llvm-svn: 234267
2015-04-07 00:39:59 +00:00
Duncan P. N. Exon Smith 3ec5fa6a1c DebugInfo: Use MDTypeRef throughout the hierarchy
Use `MDTypeRef` (etc.) in the new debug info hierarchy rather than raw
`Metadata *` pointers.

I rolled in a change to `DIBuilder` that looks unrelated: take `DIType`
instead of `DITypeRef` as type arguments when creating variables.
However, this was the simplest way to use `MDTypeRef` within the
functions, and didn't require any cleanups from callers in clang (since
they were all passing in `DIType`s anyway, relying on their implicit
conversions to `DITypeRef`).

llvm-svn: 234197
2015-04-06 19:03:45 +00:00
Duncan P. N. Exon Smith f9b4775c78 Verifier: Add operand checks for remaining debug info
llvm-svn: 233565
2015-03-30 17:21:38 +00:00
Duncan P. N. Exon Smith 0e202b95c4 Verifier: Add operand checks for MDLexicalBlock
Add operand checks for `MDLexicalBlock` and `MDLexicalBlockFile`.  Like
`MDLocalVariable` and `MDLocation`, these nodes always require a scope.

There was no test bitrot to fix here (just updated the serialization
tests in test/Assembler/mdlexicalblock.ll).

llvm-svn: 233561
2015-03-30 16:37:48 +00:00
Duncan P. N. Exon Smith 869db50ffd Verifier: Check operands of MDSubprogram nodes
Check operands of `MDSubprogram`s in the verifier, and update the
accessors and factory functions to use more specific types.

There were a lot of broken testcases, which I fixed in r233466.  If you
have out-of-tree tests for debug info, you probably need similar changes
to the ones I made there.

llvm-svn: 233559
2015-03-30 16:19:15 +00:00
Duncan P. N. Exon Smith 53855f05d3 Verifier: Check operands of MDType subclasses and MDCompileUnit
Add verify checks for `MDType` subclasses and for `MDCompileUnit`.
These new checks don't yet incorporate everything from `Verify()`, but
at least they sanity check the operands.  Also downcast accessors as
possible.

A lot of these accessors can't be downcast as far as we'd like because
of arrays of typed objects (stored in a generic `MDTuple`) and
`MDString`-based type references.  Eventually I'll port over `DIRef<>`
and `DITypedArray<>` from `DebugInfo.h` to clean those up as well.

Updated bitrotted testcases separately in r233415 and r233443 to reduce
churn on the off-chance this needs to be reverted.

llvm-svn: 233446
2015-03-27 23:05:04 +00:00
Duncan P. N. Exon Smith 3d2afaa29e Verifier: Check fields of MDVariable subclasses
Check fields from `MDLocalVariable` and `MDGlobalVariable` and change
the accessors to downcast to the right types.  `getType()` still returns
`Metadata*` since it could be an `MDString`-based reference.

Since local variables require non-null scopes, I also updated `LLParser`
to require a `scope:` field.

A number of testcases had grown bitrot and started failing with this
patch; I committed them separately in r233349.  If I just broke your
out-of-tree testcases, you're probably hitting similar problems (so have
a look there).

llvm-svn: 233389
2015-03-27 17:29:58 +00:00
Duncan P. N. Exon Smith 264899823f Verifier: Check accessors of MDLocation
Check accessors of `MDLocation`, and change them to `cast<>` down to the
right types.  Also add type-safe factory functions.

All the callers that handle broken code need to use the new versions of
the accessors (`getRawScope()` instead of `getScope()`) that still
return `Metadata*`.  This is also necessary for things like
`MDNodeKeyImpl<MDLocation>` (in LLVMContextImpl.h) that need to unique
the nodes when their operands might still be forward references of the
wrong type.

In the `Value` hierarchy, consumers that handle broken code use
`getOperand()` directly.  However, debug info nodes have a ton of
operands, and their order (even their existence) isn't stable yet.  It's
safer and more maintainable to add an explicit "raw" accessor on the
class itself.

llvm-svn: 233322
2015-03-26 22:05:04 +00:00
Duncan P. N. Exon Smith d34db1716e IR: Fix MDType fields from unsigned to uint64_t
When trying to match the current schema with the new debug info
hierarchy, I downgraded `SizeInBits`, `AlignInBits` and `OffsetInBits`
to 32-bits (oops!).  Caught this while testing my upgrade script to move
the hierarchy into place.  Bump it back up to 64-bits and update tests.

llvm-svn: 229933
2015-02-19 23:56:07 +00:00
Duncan P. N. Exon Smith 3d62bbacb1 IR: Drop scope from MDTemplateParameter
Follow-up to r229740, which removed `DITemplate*::getContext()` after my
upgrade script revealed that scopes are always `nullptr` for template
parameters.  This is the other shoe: drop `scope:` from
`MDTemplateParameter` and its two subclasses.  (Note: a bitcode upgrade
would be pointless, since the hierarchy hasn't been moved into place.)

llvm-svn: 229791
2015-02-19 00:37:21 +00:00
Duncan P. N. Exon Smith bd33d375f0 IR: Remove unnecessary fields from MDTemplateParameter
I noticed this fields were never used in r228607, but I neglected to
propagate that into `MDTemplateParameter` until now.  This really should
have been done before commit in r228640; sorry for the churn.

llvm-svn: 228652
2015-02-10 01:59:57 +00:00
Duncan P. N. Exon Smith 01fc176977 IR: Add specialized debug info metadata nodes
Add specialized debug info metadata nodes that match the `DIDescriptor`
wrappers (used by `DIBuilder`) closely.  Assembly and bitcode support to
follow soon (it'll mostly just be obvious), but this sketches in today's
schema.  This is the first big commit (well, the only *big* one aside
from the testcase changes that'll come when I move this into place) for
PR22464.

I've marked a bunch of obvious changes as `TODO`s in the source; I plan
to make those changes promptly after this hierarchy is moved underneath
`DIDescriptor`, but for now I'm aiming mostly to match the status quo.

llvm-svn: 228640
2015-02-10 00:52:32 +00:00
Duncan P. N. Exon Smith 9c26d80c18 IR: Rename 'operator ==()' to 'isKeyOf()', NFC
`isKeyOf()` is a clearer name than overloading `operator==()`.

llvm-svn: 228242
2015-02-05 00:51:35 +00:00
Duncan P. N. Exon Smith 8af6cfcdb2 IR: Reduce boilerplate in DenseMapInfo overrides, NFC
Minimize the boilerplate required for the `MDNode` subclass
`DenseMapInfo<>` overrides in `LLVMContextImpl`.

llvm-svn: 228212
2015-02-04 22:08:30 +00:00
Duncan P. N. Exon Smith 104e402610 IR: Define MDNode uniquing sets automatically, NFC
llvm-svn: 228200
2015-02-04 21:46:12 +00:00
Duncan P. N. Exon Smith d9901ff586 IR: Split out DebugInfoMetadata.h, NFC
Move debug-info-centred `Metadata` subclasses into their own
header/source file.  A couple of private template functions are needed
from both `Metadata.cpp` and `DebugInfoMetadata.cpp`, so I've moved them
to `lib/IR/MetadataImpl.h`.

llvm-svn: 227835
2015-02-02 18:53:21 +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
Duncan P. N. Exon Smith 68ab023ef7 IR: Change GenericDwarfNode::getHeader() to StringRef
Simplify the API to use a `StringRef` directly rather than exposing the
`MDString` bits underneath.

llvm-svn: 226876
2015-01-22 23:10:55 +00:00
Duncan P. N. Exon Smith e8b5e49ffd IR: DwarfNode => DebugNode, NFC
These things are potentially used for non-DWARF data (see the discussion
in PR22235), so take the `Dwarf` out of the name.  Since the new name
gives fewer clues, update the doxygen to properly describe what they
are.

llvm-svn: 226874
2015-01-22 22:47:44 +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 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 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 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
Benjamin Kramer 3280a5d9f5 Turn some DenseMaps that are only used for set operations into DenseSets.
DenseSet has better memory efficiency now.

llvm-svn: 223589
2014-12-06 19:22:54 +00:00
Benjamin Kramer 8e5dc53784 Reapply "LLVMContext: Store APInt/APFloat directly into the ConstantInt/FP DenseMaps."
This reapplies r223478 with a fix for 32 bit targets.

llvm-svn: 223586
2014-12-06 13:12:56 +00:00
NAKAMURA Takumi fc3062f65a Reformat.
llvm-svn: 223580
2014-12-06 05:57:06 +00:00
Benjamin Kramer 0dc0e54272 Revert "LLVMContext: Store APInt/APFloat directly into the ConstantInt/FP DenseMaps."
Somehow made DenseMap probe on forever on 32 bit machines.
This reverts commit r223478.

llvm-svn: 223546
2014-12-06 00:02:31 +00:00