Commit Graph

347 Commits

Author SHA1 Message Date
Peter Collingbourne 7a74803abf Bitcode: Introduce initial multi-module reader API.
Implement getLazyBitcodeModule() and parseBitcodeFile() in terms of it.

Differential Revision: https://reviews.llvm.org/D26719

llvm-svn: 287156
2016-11-16 21:44:45 +00:00
Peter Collingbourne d93620bf4d IR: Introduce inrange attribute on getelementptr indices.
If the inrange keyword is present before any index, loading from or
storing to any pointer derived from the getelementptr has undefined
behavior if the load or store would access memory outside of the bounds of
the element selected by the index marked as inrange.

This can be used, e.g. for alias analysis or to split globals at element
boundaries where beneficial.

As previously proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-July/102472.html

Differential Revision: https://reviews.llvm.org/D22793

llvm-svn: 286514
2016-11-10 22:34:55 +00:00
Peter Collingbourne 58f7f0759f Bitcode: Change the BitcodeReader to use llvm::Error internally.
Differential Revision: https://reviews.llvm.org/D26430

llvm-svn: 286323
2016-11-09 00:51:04 +00:00
Adrian Prantl dbfda63695 Add DWARF debug info support for C++11 inline namespaces.
This implements the DWARF 5 DW_AT_export_symbols feature:
http://dwarfstd.org/ShowIssue.php?issue=141212.1

<rdar://problem/18616046>

llvm-svn: 285959
2016-11-03 19:42:02 +00:00
Peter Collingbourne ff2c2ec6b2 Bitcode: Check file size before reading bitcode header.
Should unbreak ocaml binding tests.

Also added an llvm-dis test that checks for the same thing.

llvm-svn: 285777
2016-11-02 00:39:11 +00:00
Peter Collingbourne 028eb5a3f8 Bitcode: Change reader interface to take memory buffers.
As proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/106595.html

This change also fixes an API oddity where BitstreamCursor::Read() would
return zero for the first read past the end of the bitstream, but would
report_fatal_error for subsequent reads. Now we always report_fatal_error
for all reads past the end. Updated clients to check for the end of the
bitstream before reading from it.

I also needed to add padding to the invalid bitcode tests in
test/Bitcode/. This is because the streaming interface was not checking that
the file size is a multiple of 4.

Differential Revision: https://reviews.llvm.org/D26219

llvm-svn: 285773
2016-11-02 00:08:19 +00:00
Victor Leschuk 83d3f62120 DebugInfo: add bitcode upgrade test for alignment
Bitcode format was changed in D25073, this adds bitcode upgrade test.

llvm-svn: 285179
2016-10-26 08:34:19 +00:00
Victor Leschuk 2461a2e2c5 DebugInfo: remove broken bitcode upgrade test
llvm-svn: 284682
2016-10-20 00:26:36 +00:00
Victor Leschuk 2ede126b1b DebugInfo: preparation to implement DW_AT_alignment
- Add alignment attribute to DIVariable family
 - Modify bitcode format to match new DIVariable representation
 - Update tests to match these changes (also add bitcode upgrade test)
 - Expect that frontend passes non-zero align value only when it is not default
   (was forcibly aligned by alignas()/_Alignas()/__atribute__(aligned())

Differential Revision: https://reviews.llvm.org/D25073

llvm-svn: 284678
2016-10-20 00:13:12 +00:00
Adrian Prantl 3bfe1093df Teach llvm::StripDebugInfo() about global variable !dbg attachments.
This is a regression introduced by the global variable ownership
reversal performed in r281284.

rdar://problem/28448075

llvm-svn: 283784
2016-10-10 17:53:33 +00:00
Teresa Johnson 897bab9b35 [ThinLTO] Record calls to aliases
Summary:
When there is a call to an alias in the same module, we were not
adding a call edge. So we could incorrectly think that the alias
was dead if it was inlined in that function, despite having a
reference imported elsewhere. This resulted in unsats at link time.

Add a call edge when the call is to an alias.

Reviewers: davide, mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25384

llvm-svn: 283664
2016-10-08 16:11:42 +00:00
Piotr Padlewski d9830eb79f [thinlto] Basic thinlto fdo heuristic
Summary:
This patch improves thinlto importer
by importing 3x larger functions that are called from hot block.

I compared performance with the trunk on spec, and there
were about 2% on povray and 3.33% on milc. These results seems
to be consistant and match the results Teresa got with her simple
heuristic. Some benchmarks got slower but I think they are just
noisy (mcf, xalancbmki, omnetpp)- running the benchmarks again with
more iterations to confirm. Geomean of all benchmarks including the noisy ones
were about +0.02%.

I see much better improvement on google branch with Easwaran patch
for pgo callsite inlining (the inliner actually inline those big functions)
Over all I see +0.5% improvement, and I get +8.65% on povray.
So I guess we will see much bigger change when Easwaran patch will land
(it depends on new pass manager), but it is still worth putting this to trunk
before it.

Implementation details changes:
- Removed CallsiteCount.
- ProfileCount got replaced by Hotness
- hot-import-multiplier is set to 3.0 for now,
didn't have time to tune it up, but I see that we get most of the interesting
functions with 3, so there is no much performance difference with higher, and
binary size doesn't grow as much as with 10.0.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24638

llvm-svn: 282437
2016-09-26 20:37:32 +00:00
Teresa Johnson 620c140a9b [ThinLTO] Always emit a summary when compiling in ThinLTO mode
Summary:
Emit an empty summary section, instead of no summary section, when
there are no global variables in the index. This ensures that LTO
will treat these files as ThinLTO inputs, instead of as regular
LTO inputs.

In addition to not being what the user likely intended when
compiling with -flto=thin, the current behavior is problematic for
distributed build systems that expect to get ThinLTO index and imports
files back for each input compiled with -flto=thin. Combining into
a single regular LTO module also reduces the backend parallelism.
And in the case where the index was suppressed due to uses in
inline assembly, combining into a single LTO module could provoke
renaming of duplicates that we were trying to prevent by suppressing
the index.

This change required a couple of fixes to handle the empty summary
section.

Reviewers: mehdi_amini

Subscribers: mehdi_amini, llvm-commits, pcc

Differential Revision: https://reviews.llvm.org/D24779

llvm-svn: 282037
2016-09-20 23:07:17 +00:00
Mehdi Amini 7cf6382657 BitcodeWriter: fix emission of invoke when calling a var-arg function with operand bundles
llvm-svn: 281940
2016-09-19 21:27:04 +00:00
Mehdi Amini 55b06538b5 Fix test after renaming -name-anon-functions pass to -name-anon-globals
llvm-svn: 281752
2016-09-16 17:18:16 +00:00
Mehdi Amini b53b62eb69 Fix autoupgrade logic for Objective-C class properties module flag
Previous we were issuing an error when linking a module containing
the new Objective-C metadata structure for class properties with an
"old" one.
Now instead we downgrade the module flag so that the Objective-C
runtime does not expect the new metadata structure.

This is consistent with what ld64 is doing on binary files.

Differential Revision: https://reviews.llvm.org/D24620

llvm-svn: 281685
2016-09-16 00:38:18 +00:00
Peter Collingbourne d4135bbc30 DebugInfo: New metadata representation for global variables.
This patch reverses the edge from DIGlobalVariable to GlobalVariable.
This will allow us to more easily preserve debug info metadata when
manipulating global variables.

Fixes PR30362. A program for upgrading test cases is attached to that
bug.

Differential Revision: http://reviews.llvm.org/D20147

llvm-svn: 281284
2016-09-13 01:12:59 +00:00
Vedant Kumar e32490933e [Bitcode] Add compatibility test for the 3.9 release
Fork off compatibility.ll for the 3.9 release. The *.bc file in this
commit was produced using a Release build of the release_39 branch.

llvm-svn: 281059
2016-09-09 17:24:31 +00:00
Piotr Padlewski 6b96c15b83 Deleted right file
llvm-svn: 280887
2016-09-07 23:46:52 +00:00
Piotr Padlewski 3a0579f699 Revert "[thinlto] Deleted unused test file"
This reverts commit a7ad00460027c4a92640c2a5706a7d1869b60989.

llvm-svn: 280886
2016-09-07 23:46:50 +00:00
Piotr Padlewski e66bfd6bd6 [thinlto] Deleted unused test file
Summary:
This file should be referenced from
thinlto-function-summary-callgraph-pgo.ll file,
but someone forgot to use it there. Everything worked because
we store pgo data about callsite blocks, so there is no need to have
pgo count of @func.

Reviewers: tejohnson, eraman, mehdi_amini

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24309

llvm-svn: 280882
2016-09-07 23:35:46 +00:00
Teresa Johnson 4223dd8559 [PM] Port NameAnonFunction pass to new pass manager
Summary:
Port the NameAnonFunction pass and add a test.

Depends on D23439.

Reviewers: mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23440

llvm-svn: 278509
2016-08-12 14:03:36 +00:00
Teresa Johnson f93b246f8b [PM] Port ModuleSummaryIndex analysis to new pass manager
Summary:
Port the ModuleSummaryAnalysisWrapperPass to the new pass manager.
Use it in the ported BitcodeWriterPass (similar to how we use the
legacy ModuleSummaryAnalysisWrapperPass in the legacy WriteBitcodePass).

Also, pass the -module-summary opt flag through to the new pass
manager pipeline and through to the bitcode writer pass, and add
a test that uses it.

Reviewers: mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23439

llvm-svn: 278508
2016-08-12 13:53:02 +00:00
Piotr Padlewski 332b3b2210 Don't import variadic functions
Summary:
This patch adds IsVariadicFunction bit to summary in order
to not import variadic functions. Inliner doesn't inline
variadic functions because it is hard to reason about it.

This one small fix improves Importer by about 16%
(going from 86% to 100% of imported functions that are
inlined anywhere)
on some spec benchmarks like 'int' and others.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23339

llvm-svn: 278432
2016-08-11 22:13:57 +00:00
Nicolai Haehnle 84c9f9919a Add writeonly IR attribute
Summary:
This complements the earlier addition of IntrWriteMem and IntrWriteArgMem
LLVM intrinsic properties, see D18291.

Also start using the attribute for memset, memcpy, and memmove intrinsics,
and remove their special-casing in BasicAliasAnalysis.

Reviewers: reames, joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18714

llvm-svn: 274485
2016-07-04 08:01:29 +00:00
Reid Kleckner b5af11dfa3 [codeview] Add DISubprogram::ThisAdjustment
Summary:
This represents the adjustment applied to the implicit 'this' parameter
in the prologue of a virtual method in the MS C++ ABI. The adjustment is
always zero unless multiple inheritance is involved.

This increases the size of DISubprogram by 8 bytes, unfortunately. The
adjustment really is a signed 32-bit integer. If this size increase is
too much, we could probably win it back by splitting out a subclass with
info specific to virtual methods (virtuality, vindex, thisadjustment,
containingType).

Reviewers: aprantl, dexonsmith

Subscribers: aaboud, amccarth, llvm-commits

Differential Revision: http://reviews.llvm.org/D21614

llvm-svn: 274325
2016-07-01 02:41:21 +00:00
Peter Collingbourne b19924a425 BitcodeWriter: Remove redundant (and incorrect) check for whether to emit module summary.
The function name Module::empty() is slightly misleading in that it
only tests for the presence of functions in the module. However we
still want to emit the module summary if the module contains only
global variables or aliases. The presence of such entities can be
determined simply by checking the summary directly, as we are doing
below.

Differential Revision: http://reviews.llvm.org/D21669

llvm-svn: 273638
2016-06-24 01:58:02 +00:00
Peter Collingbourne 96efdd6107 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Filipe Cabecinhas 6328f8e9e6 [BitCode] Make sure atomicrmw's argument is an actual PointerType
llvm-svn: 271851
2016-06-05 18:43:40 +00:00
Filipe Cabecinhas 036e73c8bf [BitCode] Make sure storeatomic's argument is an actual PointerType
llvm-svn: 271850
2016-06-05 18:43:33 +00:00
Filipe Cabecinhas fc2a3c98e9 [BitCode] Diagnose GEPs with no indices
llvm-svn: 271849
2016-06-05 18:43:26 +00:00
Filipe Cabecinhas 2849b48fea [BitCode] Don't allow constants of void type.
llvm-svn: 271848
2016-06-05 18:43:17 +00:00
Manman Ren b5d7ff4fa3 Objective-C Class Properties: Autoupgrade "Class Properties" module flag.
When we have "Image Info Version" module flag but don't have "Class Properties"
module flag, set "Class Properties" module flag to 0, so we can correctly emit
errors when one module has the flag set and another module does not.

rdar://26469641

llvm-svn: 270791
2016-05-25 23:14:48 +00:00
Nikolay Haustov 1f7732abfa AMDGPU/SI: Add amdgpu_kernel calling convention. Part 1.
Summary:
This will be used for AMDGPU_HSA_KERNEL symbol type in output ELF.

Also, in the future unused non-kernels may be optimized.

For now, also accept SPIR_KERNEL for HCC frontend.

Also, add bitcode compatibility tests for missing calling conventions
except AVR_BUILTIN which doesn't have parse code.

Reviewers: tstellarAMD, arsenm

Subscribers: arsenm, joker.eph, llvm-commits
llvm-svn: 268717
2016-05-06 09:07:29 +00:00
Teresa Johnson 02e98331c0 [ThinLTO] Use valueid instead of bitcode offsets in combined index file
Summary:
With the removal of support for lazy parsing of combined index summary
records (e.g. r267344), we no longer need to include the summary record
bitcode offset in the VST entries for definitions. Change the combined
index format to be similar to the per-module index format in using value
ids to cross-reference from the summary record to the VST entry (rather
than the summary record bitcode offset to cross-reference in the other
direction).

The visible changes are:
1) Add the value id to the combined summary records
2) Remove the summary offset from the combined VST records, which has
the following effects:
- No longer need the VST_CODE_COMBINED_GVDEFENTRY record, as all
  combined index VST entries now only contain the value id and
  corresponding GUID.
- No longer have duplicate VST entries in the case where there are
  multiple definitions of a symbol (e.g. weak/linkonce), as they all
  have the same value id and GUID.

An implication of #2 above is that in order to hook up an alias to the
correct aliasee based on the value id of the aliasee recorded in the
combined index alias record, we need to scan the entries in the index
for that GUID to find the one from the same module (i.e. the case where
there are multiple entries for the aliasee). But the reader no longer
has to maintain a special map to hook up the alias/aliasee.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19481

llvm-svn: 267712
2016-04-27 13:28:35 +00:00
Sanjoy Das 51df5fae4a Symbolize operand bundle blocks for bcanalyzer
Reviewers: joker.eph

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19523

llvm-svn: 267524
2016-04-26 05:59:08 +00:00
Duncan P. N. Exon Smith 5892c6b94b BitcodeReader: Fix some holes in upgrade from r267296
Add tests for some missing cases to bitcode upgrade in r267296.

  - DICompositeType with an 'elements:' field, which will cause it to be
    involved in a cycle after the upgrade.

  - A DIDerivedType that references a class in 'extraData:'.

I updated test/Bitcode/dityperefs-3.8.ll with the missing cases and
regenerated test/Bitcode/dityperefs-3.8.ll.bc.

llvm-svn: 267332
2016-04-24 06:52:01 +00:00
Mehdi Amini ca2c54e04e Add "hasSection" flag in the Summary
Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19405

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267329
2016-04-24 05:31:43 +00:00
Mehdi Amini c3ed48c1bd Reorganize GlobalValueSummary with a "Flags" bitfield.
Right now it only contains the LinkageType, but will be extended
with "hasSection", "isOptSize", "hasInlineAssembly", etc.

Differential Revision: http://reviews.llvm.org/D19404

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267319
2016-04-24 03:18:18 +00:00
Mehdi Amini 8fe6936e18 Add a version field in the bitcode for the summary
Differential Revision: http://reviews.llvm.org/D19456

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267318
2016-04-24 03:18:11 +00:00
Mehdi Amini 02fa65209c Relax test using CHECK-DAG instead of CHECK-NEXT
It seems we still have some ordering issue in the combined index
emission, but I can't figure out why right now.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267306
2016-04-24 00:25:15 +00:00
Mehdi Amini 363d83f808 Fix test stability (was sensitive to the path)
This is a fixup for r267304.
The test was sensitive to the path in a subtle way:
the index in memory is sorted by GUID, which are hashes
that include the source filename for local globals.
Teresa recently added a directive at the IR level, so
we can specify it here to make the test independent of
the path.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267305
2016-04-24 00:03:57 +00:00
Mehdi Amini ae64eafd31 Store and emit original name in combined index
Summary:
As discussed in D18298, some local globals can't
be renamed/promoted (because they have a section, or because
they are referenced from inline assembly).
To be able to detect naming collision, we need to keep around
the "GUID" using their original name without taking the linkage
into account.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19454

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267304
2016-04-23 23:38:17 +00:00
Duncan P. N. Exon Smith a59d3e5af8 DebugInfo: Remove MDString-based type references
Eliminate DITypeIdentifierMap and make DITypeRef a thin wrapper around
DIType*.  It is no longer legal to refer to a DICompositeType by its
'identifier:', and DIBuilder no longer retains all types with an
'identifier:' automatically.

Aside from the bitcode upgrade, this is mainly removing logic to resolve
an MDString-based reference to an actualy DIType.  The commits leading
up to this have made the implicit type map in DICompileUnit's
'retainedTypes:' field superfluous.

This does not remove DITypeRef, DIScopeRef, DINodeRef, and
DITypeRefArray, or stop using them in DI-related metadata.  Although as
of this commit they aren't serving a useful purpose, there are patchces
under review to reuse them for CodeView support.

The tests in LLVM were updated with deref-typerefs.sh, which is attached
to the thread "[RFC] Lazy-loading of debug info metadata":

  http://lists.llvm.org/pipermail/llvm-dev/2016-April/098318.html

llvm-svn: 267296
2016-04-23 21:08:00 +00:00
Duncan P. N. Exon Smith 30805b2417 BitcodeWriter: Emit uniqued subgraphs after all distinct nodes
Since forward references for uniqued node operands are expensive (and
those for distinct node operands are cheap due to
DistinctMDOperandPlaceholder), minimize forward references in uniqued
node operands.

Moreover, guarantee that when a cycle is broken by a distinct node, none
of the uniqued nodes have any forward references.  In
ValueEnumerator::EnumerateMetadata, enumerate uniqued node subgraphs
first, delaying distinct nodes until all uniqued nodes have been
handled.  This guarantees that uniqued nodes only have forward
references when there is a uniquing cycle (since r267276 changed
ValueEnumerator::organizeMetadata to partition distinct nodes in front
of uniqued nodes as a post-pass).

Note that a single uniqued subgraph can hit multiple distinct nodes at
its leaves.  Ideally these would themselves be emitted in post-order,
but this commit doesn't attempt that; I think it requires an extra pass
through the edges, which I'm not convinced is worth it (since
DistinctMDOperandPlaceholder makes forward references quite cheap
between distinct nodes).

I've added two testcases:

  - test/Bitcode/mdnodes-distinct-in-post-order.ll is just like
    test/Bitcode/mdnodes-in-post-order.ll, except with distinct nodes
    instead of uniqued ones.  This confirms that, in the absence of
    uniqued nodes, distinct nodes are still emitted in post-order.

  - test/Bitcode/mdnodes-distinct-nodes-break-cycles.ll is the minimal
    example where a naive post-order traversal would cause one uniqued
    node to forward-reference another.  IOW, it's the motivating test.

llvm-svn: 267278
2016-04-23 04:59:22 +00:00
Duncan P. N. Exon Smith 1483fff271 BitcodeWriter: Emit distinct nodes before uniqued nodes
When an operand of a distinct node hasn't been read yet, the reader can
use a DistinctMDOperandPlaceholder.  This is much cheaper than forward
referencing from a uniqued node.  Change
ValueEnumerator::organizeMetadata to partition distinct nodes and
uniqued nodes to reduce the overhead of cycles broken by distinct nodes.

Mehdi measured this for me; this removes most of the RAUW from the
importing step of -flto=thin, even after a WIP patch that removes
string-based DITypeRefs (introducing many more cycles to the metadata
graph).

llvm-svn: 267276
2016-04-23 04:42:39 +00:00
Duncan P. N. Exon Smith c196531ef3 BitcodeWriter: Emit metadata in post-order (again)
Emit metadata nodes in post-order.  The iterative algorithm from r266709
failed to maintain this property.  After understanding my mistake, it
wasn't too hard to write a test with llvm-bcanalyzer (and I've actually
made this change once before: see r220340).

This also reverts the "noisy" testcase change from r266709.  That should
have been more of a red flag :/.

Note: The same bug crept into the ValueMapper in r265456.  I'm still
working on the fix.

llvm-svn: 266947
2016-04-21 01:55:12 +00:00
Duncan P. N. Exon Smith 9695eb3239 BitcodeWriter: Break recursion when enumerating Metadata, almost NFC
Use a worklist instead of recursing through MDNode operands in
ValueEnumerator.  The actual record output order has changed slightly,
but otherwise there's no functionality change.

I had to update test/Bitcode/metadata-function-blocks.ll.  I renumbered
nodes so they continue to match the implicit record ids.

llvm-svn: 266709
2016-04-19 03:46:51 +00:00
Mehdi Amini 2d28f7aa07 ThinLTO: Make aliases explicit in the summary
To be able to work accurately on the reference graph when taking
decision about internalizing, promoting, renaming, etc. We need
to have the alias information explicit.

Differential Revision: http://reviews.llvm.org/D18836

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266517
2016-04-16 06:56:44 +00:00
Adrian Prantl 75819aedf6 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00