Commit Graph

471 Commits

Author SHA1 Message Date
Mehdi Amini a5ee89863c Revert "Use StringRef in LTOModule implementation (NFC)"
This reverts commit r282997, a windows bot is asserting in
one test apparently.

llvm-svn: 283456
2016-10-06 15:12:22 +00:00
Mehdi Amini 4cc259a469 Use StringRef in LTOCodegenerator (NFC)
llvm-svn: 282998
2016-10-01 01:18:23 +00:00
Mehdi Amini 05cfdd0800 Use StringRef in LTOModule implementation (NFC)
llvm-svn: 282997
2016-10-01 01:18:16 +00:00
Peter Collingbourne f75609e015 Add explanatory comment.
llvm-svn: 282678
2016-09-29 03:29:28 +00:00
Peter Collingbourne 0d5636e517 LTO: Fix use-after-scope error.
llvm-svn: 282665
2016-09-29 01:28:36 +00:00
Dehao Chen 5461d8bdb5 Refactor the ProfileSummaryInfo to use doInitialization and doFinalization to handle Module update.
Summary: This refactors the change in r282616

Reviewers: davidxl, eraman, mehdi_amini

Subscribers: mehdi_amini, davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D25041

llvm-svn: 282630
2016-09-28 21:00:58 +00:00
Dehao Chen 10d0abb515 Fix the bug introduced in r282616.
llvm-svn: 282618
2016-09-28 18:54:36 +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
Peter Collingbourne a638fe057c Add qualification to fix MSVC build.
llvm-svn: 282313
2016-09-23 23:23:23 +00:00
Peter Collingbourne 80186a57d6 LTO: Simplify caching interface.
The NativeObjectOutput class has a design problem: it mixes up the caching
policy with the interface for output streams, which makes the client-side
code hard to follow and would for example make it harder to replace the
cache implementation in an arbitrary client.

This change separates the two aspects by moving the caching policy
to a separate field in Config, replacing NativeObjectOutput with a
NativeObjectStream class which only deals with streams and does not need to
be overridden by most clients and introducing an AddFile callback for adding
files (e.g. from the cache) to the link.

Differential Revision: https://reviews.llvm.org/D24622

llvm-svn: 282299
2016-09-23 21:33:43 +00:00
Teresa Johnson 3f212b8908 [ThinLTO] Emit files for distributed builds for all modules
With the new LTO API in r278338, we stopped emitting the individual
index files and imports files for some modules in the distributed backend
case (thinlto-index-only plugin option).

Specifically, this is when the linker decides not to include a module in the
link, because it was in an archive library and did not have a strong
reference to it. Not creating the expected output files makes the
distributed build system implementation more difficult, in terms of
checking for the expected outputs of the thin link, and scheduling the
backend jobs. To address this, the gold-plugin will write dummy empty
.thinlto.bc and .imports files for modules not included in the link
(which LTO never sees).

Augmented a gold v1.12+ test, since that version of gold has the handling
for notifying on modules not being included in the link.

llvm-svn: 282100
2016-09-21 19:12:05 +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
Davide Italiano a416d11357 [lib/LTO] Try harder to reduce code duplication. NFCI.
llvm-svn: 281843
2016-09-17 22:32:42 +00:00
Davide Italiano 14e9e8af35 [LTO] Add ability to parse AA pipelines.
This is supposed to be a drop in replacement for what lld
provides via --lto-newpm-aa-pipeline.

llvm-svn: 281774
2016-09-16 21:03:21 +00:00
Davide Italiano dc8e07b98e [LTO] Prevent asm references to be dropped from the output.
Differential Revision:  https://reviews.llvm.org/D24617

llvm-svn: 281741
2016-09-16 16:05:25 +00:00
Teresa Johnson 8dd61aee30 [LTO] Fix handling of mixed (regular and thin) mode LTO
Summary:
In runThinLTO we start the task numbering for ThinLTO backend
tasks depending on whether there was also a regular LTO object
(CombinedModule). However, the CombinedModule is moved at
the end of runRegularLTO, so we need to save this information and
pass it into runThinLTO. Otherwise the AddOutput callback to the client
will use the same task number for both the regular LTO object
and the first ThinLTO object, which in gold-plugin caused only
one to be end up in the output filename array and therefore passed
back to gold for the final native link.

Reviewers: pcc, mehdi_amini

Subscribers: mehdi_amini, kromanova

Differential Revision: https://reviews.llvm.org/D24643

llvm-svn: 281725
2016-09-16 13:54:19 +00:00
Eric Christopher 4367c7fb9a Move the Mangler from the AsmPrinter down to TLOF and clean up the
TLOF API accordingly.

llvm-svn: 281708
2016-09-16 07:33:15 +00:00
Mehdi Amini b2f46d1dc7 [LTO] Fix commons handling
Previously the prevailing information was not honored, and commons
symbols could override a strong definition. This patch fixes it and
propose the following semantic for commons: the client should mark
as prevailing the commons that it expects the LTO implementation to
merge (i.e. take the maximum size and alignment).
It implies that commons are allowed to have multiple prevailing
definitions.

Differential Revision: https://reviews.llvm.org/D24545

llvm-svn: 281538
2016-09-14 21:05:04 +00:00
Davide Italiano 63e8f444c7 [lib/LTO] Fix a typo. NFC.
llvm-svn: 281517
2016-09-14 18:48:43 +00:00
Davide Italiano 39ccd24126 [LTO] Don't pass SF_Undefined symbols to the IRmover.
This should fix PR 30363.

llvm-svn: 281366
2016-09-13 18:45:13 +00:00
Davide Italiano ec9612da1a [lib/LTO] Add a way to run a custom pipeline
Differential Revision:  https://reviews.llvm.org/D24095

llvm-svn: 280830
2016-09-07 17:46:16 +00:00
Davide Italiano 24c29b1426 [LTO] Rename variables to be more explicative.
Thanks to Mehdi for the suggestion!

llvm-svn: 280772
2016-09-07 01:08:31 +00:00
Mehdi Amini 767e1457d8 [LTO] Constify (NFC)
llvm-svn: 280687
2016-09-06 03:23:45 +00:00
Davide Italiano 41bfd6bd6c [lib/LTO] Simplify. No functional change intended.
llvm-svn: 280503
2016-09-02 16:37:31 +00:00
Davide Italiano 22d36c167e [lib/LTO] Simplify a bit. NFCI.
llvm-svn: 280396
2016-09-01 18:34:47 +00:00
Davide Italiano 1e9d3d3b40 [lib/LTO] Factor out logic for running passes.
This is in preparation for adding an option
to run a custom pipeline with the new PM. It's
currently used in lld.

llvm-svn: 280258
2016-08-31 17:02:44 +00:00
Teresa Johnson 6e711c33b4 [LTO] Remove extraneous output
Remove some debugging output to stderr that snuck in with r279576.

llvm-svn: 279974
2016-08-29 15:33:01 +00:00
Teresa Johnson e2e621a36c [LTO] Don't create a new common unless merged has different size
Summary:
This addresses a regression in common handling from the new LTO
API in r278338. Only create a new common if the size is different.
The type comparison against an array type fails when the size is
different but not an array. GlobalMerge does not handle the
array types as well and we lose some global merging opportunities.

Reviewers: mehdi_amini

Subscribers: junbuml, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23955

llvm-svn: 279911
2016-08-27 04:41:22 +00:00
Teresa Johnson 26a462877b [ThinLTO] Move loading of cache entry to client
Summary:
Have the cache pass back the path to the cache entry when it
is ready to be loaded, instead of a buffer.

For gold-plugin we can simply pass this file back to gold directly,
which avoids expensive writing of a separate tmp file. Ensure
the cache entry is not deleted on cleanup by adjusting the setting
of the IsTemporary flags.

Moved the loading of the buffer into llvm-lto2 to maintain current
behavior.

Reviewers: mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23946

llvm-svn: 279883
2016-08-26 23:29:14 +00:00
Rafael Espindola 7775c3310c Make writeToResolutionFile a static helper.
llvm-svn: 279859
2016-08-26 20:19:35 +00:00
Davide Italiano f8014f82ed [lib/LTO] Add an assertion to catch invalid opt levels.
llvm-svn: 279823
2016-08-26 15:22:59 +00:00
Mehdi Amini adc0e26bef [ThinLTO] Add caching to the new LTO API
Add the ability to plug a cache on the LTO API.
I tried to write such that a linker implementation can
control the cache backend. This is intrusive and I'm
not totally happy with it, but I can't figure out a
better design right now.

Differential Revision: https://reviews.llvm.org/D23599

llvm-svn: 279576
2016-08-23 21:30:12 +00:00
Mehdi Amini e7494530b2 Stop always creating and running an LTO compilation if there is not a single LTO object
Summary:
I assume there was a use case, so maybe this strawman patch will help
clarifying if it is legit.
In any case the current situation is not legit: a ThinLTO compilation
should not trigger an unexpected full LTO compilation.
Right now, adding a --save-temps option triggers this and makes the
number of output differs.

Reviewers: tejohnson

Subscribers: pcc, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23600

llvm-svn: 279550
2016-08-23 18:39:12 +00:00
Mehdi Amini 9ec5a61358 [ThinLTO] Make sure the Context used for the ThinLTO backend has all the appropriate options
An important performance setting on the LLVMContext for LTO is
enableDebugTypeODRUniquing(), this adds an automatic merging of
debug information in the context based on type ids.

Also, the lto::Config includes a diagnostic handler that needs to
be set on the Context, as well as the setDiscardValueNames() setting.

llvm-svn: 279532
2016-08-23 16:53:34 +00:00
Davide Italiano fc4430ea45 [LTOCodeGenerator] Reduce code duplication. NFCI.
llvm-svn: 279514
2016-08-23 12:32:57 +00:00
Mehdi Amini f8c2f08cb3 [LTO] Constify the Module Hook function (NFC)
It use to be non-const for the sole purpose of custom handling of
commons symbol. This is moved now in the regular LTO handling now
and such we can constify the callback.

llvm-svn: 279438
2016-08-22 16:17:40 +00:00
Mehdi Amini dc4c8cf9ac [LTO] Handles commons in monolithic LTO
The gold-plugin was doing this internally, now the API is handling
commons correctly based on the given resolution.

Differential Revision: https://reviews.llvm.org/D23739

llvm-svn: 279417
2016-08-22 06:25:46 +00:00
Mehdi Amini d310b47c23 [LTO] Add a "CodeGenOnly" option. Allows the client to skip the optimizer.
Summary: Slowly getting on par with libLTO

Reviewers: tejohnson

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23615

llvm-svn: 279416
2016-08-22 06:25:41 +00:00
Mehdi Amini 9989f80ae8 [LTO] Remove dead-code: collectUsedGlobalVariables has been moved to Thin and LTO specifc path (NFC)
llvm-svn: 279261
2016-08-19 15:35:44 +00:00
Chandler Carruth b7be5b6479 [PM] Rework the new PM support for building the ModuleSummaryIndex to
directly produce the index as the value type result.

This requires making the index movable which is straightforward. It
greatly simplifies things by allowing us to completely avoid the builder
API and the layers of abstraction inherent there. Instead both pass
managers can directly construct these when run by value. They still
won't be constructed truly eagerly thanks to the optional in the legacy
PM. The code that directly builds the index can also just share a direct
function.

A notable change here is that the result type of the analysis for the
new PM is no longer a reference type. This was really problematic when
making changes to how we handle result types to make our interface
requirements *much* more strict and precise. But I think this is an
overall improvement.

Differential Revision: https://reviews.llvm.org/D23701

llvm-svn: 279216
2016-08-19 07:49:19 +00:00
Mehdi Amini 18b91112af [LTO] Move callback member from base class to the derived where it is used (NFC)
llvm-svn: 279212
2016-08-19 06:10:03 +00:00
Mehdi Amini 026ddbb4d6 [LTO] Add a move to inialize member in ctor initialization list (NFC)
llvm-svn: 279210
2016-08-19 05:56:37 +00:00
Mehdi Amini 8ac7b32207 [LTO] Promote before performing weak resolution
Summary:
This was reversed compared to ThinLTOCodeGenerator for some reason,
and lead to an increased code-size on my tests. I figured that the
weak resolution may internalize a linkonce function, which will be
promoted immediately (and renamed), before being internalized again.

Reviewers: tejohnson

Subscribers: pcc, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23632

llvm-svn: 279021
2016-08-18 00:59:24 +00:00
Mehdi Amini eccffada33 [LTO] Change addSaveTemps API: do not add dot to the supplied prefix path
Summary:
It does not play well with directories (end up with a bunch of hidden
files).
Also, do not strip the 0 suffix for the first task, especially since
0 can be used by ThinLTO as well now.

Reviewers: tejohnson

Subscribers: mehdi_amini, pcc, llvm-commits

Differential Revision: https://reviews.llvm.org/D23612

llvm-svn: 279014
2016-08-18 00:12:33 +00:00
Mehdi Amini 970800e0c8 [LTO] Introduce an Output class to wrap the output stream creation (NFC)
Summary:
While NFC for now, this will allow more flexibility on the client side
to hold state necessary to back up the stream.
Also when adding caching, this class will grow in complexity.

Note I blindly modified the gold-plugin as I can't compile it.

Reviewers: tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23542

llvm-svn: 278907
2016-08-17 06:23:09 +00:00
Mehdi Amini cdbcbf7477 [LTO] Simplify APIs and constify (NFC)
Summary:
Multiple APIs were taking a StringMap for the ImportLists containing
the entries for for all the modules while operating on a single entry
for the current module. Instead we can pass the desired ModuleImport
directly. Also some of the APIs were not const, I believe just to be
able to use operator[] on the StringMap.

Reviewers: tejohnson

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23537

llvm-svn: 278776
2016-08-16 05:46:05 +00:00
Mehdi Amini acc50c4334 [LTO] Rename variables with meaningul names, i.e. more than one character (NFC)
llvm-svn: 278766
2016-08-16 00:44:46 +00:00
Teresa Johnson c44a12244f [ThinLTO] Fix temp file dumping, enable via llvm-lto and test it
Summary:
Fixed a bug in ThinLTOCodeGenerator's temp file dumping. The Twine
needs to be passed directly as an argument, or a copy saved into a
std::string.

It doesn't seem there are any consumers of this, so I added a new option
to llvm-lto to enable saving of temp files during ThinLTO, and augmented
a test to use it to check post-import but pre-opt bitcode.

Reviewers: mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23525

llvm-svn: 278761
2016-08-15 23:24:57 +00:00
Teresa Johnson faa7506f18 Fix type truncation warnings
Avoid type truncation warnings from a 32-bit bot due to size_t not
being unsigned long long, by converting the variables and constants to
unsigned. This was introduced by r278338 and caused warnings here:
http://bb.pgr.jp/builders/i686-mingw32-RA-on-linux/builds/15527/steps/build_llvmclang/logs/warnings%20%287%29

llvm-svn: 278406
2016-08-11 20:38:39 +00:00
Teresa Johnson 9ba95f99f3 Restore "Resolution-based LTO API."
This restores commit r278330, with fixes for a few bot failures:
- Fix a late change I had made to the save temps output file that I
  missed due to existing files sitting on my disk
- Fix a bunch of Windows bot failures with "ambiguous call to overloaded
  function" due to confusion between llvm::make_unique vs
  std::make_unique (preface the new make_unique calls with "llvm::")
- Attempt to fix a modules bot failure by adding a missing include
  to LTO/Config.h.

Original change:

Resolution-based LTO API.

Summary:
This introduces a resolution-based LTO API. The main advantage of this API over
existing APIs is that it allows the linker to supply a resolution for each
symbol in each object, rather than the combined object as a whole. This will
become increasingly important for use cases such as ThinLTO which require us
to process symbol resolutions in a more complicated way than just adjusting
linkage.

Patch by Peter Collingbourne.

Reviewers: rafael, tejohnson, mehdi_amini

Subscribers: lhames, tejohnson, mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D20268

llvm-svn: 278338
2016-08-11 14:58:12 +00:00
Teresa Johnson cbf684e6c6 Revert "Resolution-based LTO API."
This reverts commit r278330.

I made a change to the save temps output that is causing issues with the
bots. Didn't realize this because I had older output files sitting on
disk in my test output directory.

llvm-svn: 278331
2016-08-11 13:03:56 +00:00
Teresa Johnson f99573b3ee Resolution-based LTO API.
Summary:
This introduces a resolution-based LTO API. The main advantage of this API over
existing APIs is that it allows the linker to supply a resolution for each
symbol in each object, rather than the combined object as a whole. This will
become increasingly important for use cases such as ThinLTO which require us
to process symbol resolutions in a more complicated way than just adjusting
linkage.

Patch by Peter Collingbourne.

Reviewers: rafael, tejohnson, mehdi_amini

Subscribers: lhames, tejohnson, mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D20268

Address review comments

llvm-svn: 278330
2016-08-11 12:56:40 +00:00
Peter Collingbourne 5c73220fa5 Move legacy LTO interface headers to legacy/ directory.
Differential Revision: https://reviews.llvm.org/D22173

llvm-svn: 275476
2016-07-14 21:21:16 +00:00
Dehao Chen 9cba1f4e7e New pass manager for LICM.
Summary: Port LICM to the new pass manager.

Reviewers: davidxl, silvas

Subscribers: krasin, vitalybuka, silvas, davide, sanjoy, llvm-commits, mehdi_amini

Differential Revision: http://reviews.llvm.org/D21772

llvm-svn: 275222
2016-07-12 22:37:48 +00:00
Vitaly Buka 204dc533c5 Revert "New pass manager for LICM."
Summary: This reverts commit r275118.

Subscribers: sanjoy, mehdi_amini

Differential Revision: http://reviews.llvm.org/D22259

llvm-svn: 275156
2016-07-12 06:25:32 +00:00
Dehao Chen 7ef5820fa3 New pass manager for LICM.
Summary: Port LICM to the new pass manager.

Reviewers: davidxl, silvas

Subscribers: silvas, davide, sanjoy, llvm-commits, mehdi_amini

Differential Revision: http://reviews.llvm.org/D21772

llvm-svn: 275118
2016-07-11 22:45:24 +00:00
Peter Collingbourne 73589f321b ThinLTO: Do not take into account whether a definition has multiple copies when promoting.
We currently do not touch a symbol's linkage in the case where a definition
has a single copy. However, this code is effectively unnecessary: either
the definition is not exported, in which case the internalize phase sets
its linkage to internal, or it is exported, in which case we need to promote
linkage to weak. Those two cases are already handled by existing code.

I believe that the only real functional change here is in the case where we
have a single definition which does not prevail (e.g. because the definition
in a native object file prevails). In that case we now lower linkage to
available_externally following the existing code path for that case.

As a result we can remove the isExported function parameter from the
thinLTOResolveWeakForLinkerInIndex function.

Differential Revision: http://reviews.llvm.org/D21883

llvm-svn: 274784
2016-07-07 18:31:51 +00:00
Peter Collingbourne 730c82e6b8 ThinLTO: Remove check for multiple modules before applying weak resolutions.
This check is not only unnecessary, it can produce the wrong result. If we
are linking a single module and it has an exported linkonce symbol, we need
to promote to weak in order to avoid PR19901-style problems.

Differential Revision: http://reviews.llvm.org/D21917

llvm-svn: 274722
2016-07-07 01:51:11 +00:00
Davide Italiano 53d457c615 [UpdateCompilerUsed] API rename and cleanup, suggested by Rafaael.
* UpdateCompilerUsed() -> updateCompilerUsed()
* ThinLTO doesn't use the API so we can remove the include
* Clean up unused #include <functional> from the header
* Rename #ifdef guard comment to be correct.

llvm-svn: 273461
2016-06-22 19:50:42 +00:00
Davide Italiano da5b8495e2 [LTO] Move UpdateCompilerUsed.h from lib/ to include/
I plan to use it in lld soon.

Differential Revision:  http://reviews.llvm.org/D21575

llvm-svn: 273380
2016-06-22 04:52:43 +00:00
Davide Italiano b49aa5c0c4 [PM] Port MergedLoadStoreMotion to the new pass manager, take two.
This is indeed a much cleaner approach (thanks to Daniel Berlin
for pointing out), and also David/Sean for review.

Differential Revision:  http://reviews.llvm.org/D21454

llvm-svn: 273032
2016-06-17 19:10:09 +00:00
Davide Italiano 41315f7873 [PM] Revert the port of MergeLoadStoreMotion to the new pass manager.
Daniel Berlin expressed some real concerns about the port and proposed
and alternative approach. I'll revert this for now while working on a
new patch, which I hope to put up for review shortly. Sorry for the churn.

llvm-svn: 272925
2016-06-16 17:40:53 +00:00
David Majnemer cbf614a93b Remove the ScalarReplAggregates pass
Nearly all the changes to this pass have been done while maintaining and
updating other parts of LLVM.  LLVM has had another pass, SROA, which
has superseded ScalarReplAggregates for quite some time.

Differential Revision: http://reviews.llvm.org/D21316

llvm-svn: 272737
2016-06-15 00:19:09 +00:00
Sean Silva 6347df0f81 [PM] Port MemCpyOpt to the new PM.
The need for all these Lookup* functions is just because of calls to
getAnalysis inside methods (i.e. not at the top level) of the
runOnFunction method. They should be straightforward to clean up when
the old PM is gone.

llvm-svn: 272615
2016-06-14 02:44:55 +00:00
Davide Italiano 89ab89d6cd [PM] Port MergedLoadStoreMotion to the new pass manager.
llvm-svn: 272606
2016-06-14 00:49:23 +00:00
Benjamin Kramer d3f4c05aea Move instances of std::function.
Or replace with llvm::function_ref if it's never stored. NFC intended.

llvm-svn: 272513
2016-06-12 16:13:55 +00:00
Sean Silva f5080194fd [PM] Port ReversePostOrderFunctionAttrs to the new PM
Below are my super rough notes when porting. They can probably serve as
a basic guide for porting other passes to the new PM. As I port more
passes I'll expand and generalize this and make a proper
docs/HowToPortToNewPassManager.rst document. There is also missing
documentation for general concepts and API's in the new PM which will
require some documentation.
Once there is proper documentation in place we can put up a list of
passes that have to be ported and game-ify/crowdsource the rest of the
porting (at least of the middle end; the backend is still unclear).

I will however be taking personal responsibility for ensuring that the
LLD/ELF LTO pipeline is ported in a timely fashion. The remaining passes
to be ported are (do something like
`git grep "<the string in the bullet point below>"` to find the pass):

General Scalar:
[ ] Simplify the CFG
[ ] Jump Threading
[ ] MemCpy Optimization
[ ] Promote Memory to Register
[ ] MergedLoadStoreMotion
[ ] Lazy Value Information Analysis

General IPO:
[ ] Dead Argument Elimination
[ ] Deduce function attributes in RPO

Loop stuff / vectorization stuff:
[ ] Alignment from assumptions
[ ] Canonicalize natural loops
[ ] Delete dead loops
[ ] Loop Access Analysis
[ ] Loop Invariant Code Motion
[ ] Loop Vectorization
[ ] SLP Vectorizer
[ ] Unroll loops

Devirtualization / CFI:
[ ] Cross-DSO CFI
[ ] Whole program devirtualization
[ ] Lower bitset metadata

CGSCC passes:
[ ] Function Integration/Inlining
[ ] Remove unused exception handling info
[ ] Promote 'by reference' arguments to scalars

Please let me know if you are interested in working on any of the passes
in the above list (e.g. reply to the post-commit thread for this patch).
I'll probably be tackling "General Scalar" and "General IPO" first FWIW.

Steps as I port "Deduce function attributes in RPO"
---------------------------------------------------

(note: if you are doing any work based on these notes, please leave a
note in the post-commit review thread for this commit with any
improvements / suggestions / incompleteness you ran into!)

Note: "Deduce function attributes in RPO" is a module pass.

1. Do preparatory refactoring.

Do preparatory factoring. In this case all I had to do was to pull out a static helper (r272503).
(TODO: give more advice here e.g. if pass holds state or something)

2. Rename the old pass class.

llvm/lib/Transforms/IPO/FunctionAttrs.cpp
Rename class ReversePostOrderFunctionAttrs -> ReversePostOrderFunctionAttrsLegacyPass
in preparation for adding a class ReversePostOrderFunctionAttrs as the pass in the new PM.
(edit: actually wait what? The new class name will be
ReversePostOrderFunctionAttrsPass, so it doesn't conflict. So this step is
sort of useless churn).

llvm/include/llvm/InitializePasses.h
llvm/lib/LTO/LTOCodeGenerator.cpp
llvm/lib/Transforms/IPO/IPO.cpp
llvm/lib/Transforms/IPO/FunctionAttrs.cpp
Rename initializeReversePostOrderFunctionAttrsPass -> initializeReversePostOrderFunctionAttrsLegacyPassPass
(note that the "PassPass" thing falls out of `s/ReversePostOrderFunctionAttrs/ReversePostOrderFunctionAttrsLegacyPass/`)
Note that the INITIALIZE_PASS macro is what creates this identifier name, so renaming the class requires this renaming too.

Note that createReversePostOrderFunctionAttrsPass does not need to be
renamed since its name is not generated from the class name.

3. Add the new PM pass class.

In the new PM all passes need to have their
declaration in a header somewhere, so you will often need to add a header.
In this case
llvm/include/llvm/Transforms/IPO/FunctionAttrs.h is already there because
PostOrderFunctionAttrsPass was already ported.
The file-level comment from the .cpp file can be used as the file-level
comment for the new header. You may want to tweak the wording slightly
from "this file implements" to "this file provides" or similar.

Add declaration for the new PM pass in this header:

    class ReversePostOrderFunctionAttrsPass
        : public PassInfoMixin<ReversePostOrderFunctionAttrsPass> {
    public:
      PreservedAnalyses run(Module &M, AnalysisManager<Module> &AM);
    };

Its name should end with `Pass` for consistency (note that this doesn't
collide with the names of most old PM passes). E.g. call it
`<name of the old PM pass>Pass`.

Also, move the doxygen comment from the old PM pass to the declaration of
this class in the header.
Also, include the declaration for the new PM class
`llvm/Transforms/IPO/FunctionAttrs.h` at the top of the file (in this case,
it was already done when the other pass in this file was ported).

Now define the `run` method for the new class.
The main things here are:
a) Use AM.getResult<...>(M) to get results instead of `getAnalysis<...>()`

b) If the old PM pass would have returned "false" (i.e. `Changed ==
false`), then you should return PreservedAnalyses::all();

c) In the old PM getAnalysisUsage method, observe the calls
   `AU.addPreserved<...>();`.

   In the case `Changed == true`, for each preserved analysis you should do
   call `PA.preserve<...>()` on a PreservedAnalyses object and return it.
   E.g.:

       PreservedAnalyses PA;
       PA.preserve<CallGraphAnalysis>();
       return PA;

Note that calls to skipModule/skipFunction are not supported in the new PM
currently, so optnone and optimization bisect support do not work. You can
just drop those calls for now.

4. Add the pass to the new PM pass registry to make it available in opt.

In llvm/lib/Passes/PassBuilder.cpp add a #include for your header.
`#include "llvm/Transforms/IPO/FunctionAttrs.h"`
In this case there is already an include (from when
PostOrderFunctionAttrsPass was ported).

Add your pass to llvm/lib/Passes/PassRegistry.def
In this case, I added
`MODULE_PASS("rpo-functionattrs", ReversePostOrderFunctionAttrsPass())`
The string is from the `INITIALIZE_PASS*` macros used in the old pass
manager.

Then choose a test that uses the pass and use the new PM `-passes=...` to
run it.
E.g. in this case there is a test that does:
; RUN: opt < %s -basicaa -functionattrs -rpo-functionattrs -S | FileCheck %s
I have added the line:
; RUN: opt < %s -aa-pipeline=basic-aa -passes='require<targetlibinfo>,cgscc(function-attrs),rpo-functionattrs' -S | FileCheck %s
The `-aa-pipeline=basic-aa` and
`require<targetlibinfo>,cgscc(function-attrs)` are what is needed to run
functionattrs in the new PM (note that in the new PM "functionattrs"
becomes "function-attrs" for some reason). This is just pulled from
`readattrs.ll` which contains the change from when functionattrs was ported
to the new PM.
Adding rpo-functionattrs causes the pass that was just ported to run.

llvm-svn: 272505
2016-06-12 07:48:51 +00:00
Benjamin Kramer c321e53402 Apply most suggestions of clang-tidy's performance-unnecessary-value-param
Avoids unnecessary copies. All changes audited & pass tests with asan.
No functional change intended.

llvm-svn: 272190
2016-06-08 19:09:22 +00:00
Teresa Johnson 28c03b56ec [ThinLTO] Resolve LinkOnceAny
Summary:
Ensure we keep prevailing copy of LinkOnceAny by converting it to
WeakAny.

Rename odr_resolution test to the now more appropriate weak_resolution
(weak in the linker sense includes linkonce).

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D20634

llvm-svn: 270850
2016-05-26 14:16:52 +00:00
Teresa Johnson 04c9a2d63d [ThinLTO] Refactor ODR resolution and internalization (NFC)
Move the now index-based ODR resolution and internalization routines out
of ThinLTOCodeGenerator.cpp and into either LTO.cpp (index-based
analysis) or FunctionImport.cpp (index-driven optimizations).
This is to enable usage by other linkers.

llvm-svn: 270698
2016-05-25 14:03:11 +00:00
Teresa Johnson 4ae5ce7e8e [ThinLTO] Handle empty exports list for module.
We might have an empty exports list for a module and shouldn't assert
when checking if a symbol is exported.

llvm-svn: 270600
2016-05-24 19:12:48 +00:00
Teresa Johnson 141149ff48 [ThinLTO] Fix bot failures by avoiding threaded map modifications
Ensure multiple threads won't have to modify map, probable cause of
bot failures from r270584 such as:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/13095

llvm-svn: 270595
2016-05-24 18:44:01 +00:00
Teresa Johnson 4d2613f276 [ThinLTO] Change ODR resolution and internalization to be index-based
Summary:
This patch changes the ODR resolution and internalization to be based on
updates to the Index, which are consumed by the backend portion of the
transformations.

It will be followed by an NFC change to move these out of libLTO's
ThinLTOCodeGenerator so that it can be used by other linkers
(gold and lld) and by ThinLTO distributed backends.

The global summary-based portions use callbacks so that the client can
determine the prevailing copy and other information in a client-specific
way. Eventually, with the API being developed in D20268, these may be
modified to use information such as symbol resolutions, supplied by the
clients to the API.

Reviewers: joker-eph

Subscribers: joker.eph, pcc, llvm-commits

Differential Revision: http://reviews.llvm.org/D20290

llvm-svn: 270584
2016-05-24 17:24:25 +00:00
Teresa Johnson df6edc5277 [ThinLTO] Refactor module loader handling into new LTO file (NFC)
Moved the ModuleLoader and supporting helper loadModuleFromBuffer out of
ThinLTOCodeGenerator and into new LTO.h/LTO.cpp files. This is in
preparation for a patch that will utilize these in the gold-plugin.

Note that there are some other pending patches (D20268 and D20290) that
also plan to refactor common interfaces and functionality into this same
pair of new files.

llvm-svn: 270509
2016-05-23 22:54:06 +00:00
Rafael Espindola 8c34dd8257 Delete Reloc::Default.
Having an enum member named Default is quite confusing: Is it distinct
from the others?

This patch removes that member and instead uses Optional<Reloc> in
places where we have a user input that still hasn't been maped to the
default value, which is now clear has no be one of the remaining 3
options.

llvm-svn: 269988
2016-05-18 22:04:49 +00:00
Mehdi Amini 819e9cdfb4 ThinLTO: sort inputs and schedule by decreasing size
This is a compile time optimization: keeping a large file to process
at the end hurts parallelism.
The heurisitic used right now is the input buffer size, however we
may want to consider the number of functions to import or the
different number of files to load for importing as well.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269684
2016-05-16 19:33:07 +00:00
Mehdi Amini 001bb41556 ThinLTO caching: reload cached file with mmap and drop heap-allocated memory buffer
This is reducing pressure on the OS memory system, and is NFC
when not using a cache.
I measure a 10x memory consumption reduction when linking opt
with full debug info.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269682
2016-05-16 19:11:59 +00:00
Mehdi Amini af52f28d9d ThinLTOCodeGenerator: fix race condition found using TSAN
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269588
2016-05-15 05:49:47 +00:00
Mehdi Amini b02139d66f ThinLTOCodeGenerator: handle cases where temporary files can't be renamed
For instance when they're on different filesystem.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269544
2016-05-14 05:16:35 +00:00
Mehdi Amini 2a16a5fae5 ThinLTOCodeGenerator: handle std::error_code instead of silently dropping it.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269541
2016-05-14 04:58:38 +00:00
Teresa Johnson 8570fe47ef [ThinLTO] Add option to emit imports files for distributed backends
Summary:
Add support for emission of plaintext lists of the imported files for
each distributed backend compilation. Used for distributed build file
staging.

Invoked with new gold-plugin thinlto-emit-imports-files option, which is
only valid with thinlto-index-only (i.e. for distributed builds), or
from llvm-lto with new -thinlto-action=emitimports value.

Depends on D19556.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19636

llvm-svn: 269067
2016-05-10 15:54:09 +00:00
Teresa Johnson 84174c3771 Restore "[ThinLTO] Emit individual index files for distributed backends"
This restores commit r268627:
    Summary:
    When launching ThinLTO backends in a distributed build (currently
    supported in gold via the thinlto-index-only plugin option), emit
    an individual index file for each backend process as described here:
    http://lists.llvm.org/pipermail/llvm-dev/2016-April/098272.html

    ...

    Differential Revision: http://reviews.llvm.org/D19556

Address msan failures by avoiding std::prev on map.end(), the
theory is that this is causing issues due to some known UB problems
in __tree.

llvm-svn: 269059
2016-05-10 13:48:23 +00:00
Adrian Prantl fe7a382453 Allow the LTO code generator to strip invalid debug info from the input.
This patch introduces a new option -lto-strip-invalid-debug-info, which
drops malformed debug info from the input.

The problem I'm trying to solve with this sequence of patches is that
historically we've done a really bad job at verifying debug info. We want
to be able to make the verifier stricter without having to worry about
breaking bitcode compatibility with existing producers. For example, we
don't necessarily want IR produced by an older version of clang to be
rejected by an LTO link just because of malformed debug info, and rather
provide an option to strip it. Note that merely outdated (but well-formed)
debug info would continue to be auto-upgraded in this scenario.

rdar://problem/25818489
http://reviews.llvm.org/D19987

This reapplies 268936 with a test case fix for Linux (-exported-symbol foo)

llvm-svn: 268965
2016-05-09 19:57:15 +00:00
Adrian Prantl 6d80100c6a Revert "Allow the LTO code generator to strip invalid debug info from the input."
This reverts commit 268936 while investigating buildbot breakage.

llvm-svn: 268940
2016-05-09 17:43:30 +00:00
Adrian Prantl 4a9292b127 Allow the LTO code generator to strip invalid debug info from the input.
This patch introduces a new option -lto-strip-invalid-debug-info, which
drops malformed debug info from the input.

The problem I'm trying to solve with this sequence of patches is that
historically we've done a really bad job at verifying debug info. We want
to be able to make the verifier stricter without having to worry about
breaking bitcode compatibility with existing producers. For example, we
don't necessarily want IR produced by an older version of clang to be
rejected by an LTO link just because of malformed debug info, and rather
provide an option to strip it. Note that merely outdated (but well-formed)
debug info would continue to be auto-upgraded in this scenario.

rdar://problem/25818489
http://reviews.llvm.org/D19987

llvm-svn: 268936
2016-05-09 17:37:33 +00:00
Davide Italiano f54f2f0893 [PM] Port Interprocedural SCCP to the new pass manager.
llvm-svn: 268684
2016-05-05 21:05:36 +00:00
Mehdi Amini 5eba657ff3 Revert "LTOCodeGenerator: handle correctly "unnamed" symbol"
This reverts commit r268658.

I incorrectly diagnose this as the source of an assertion during an
LTO bootstrap of clang.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268680
2016-05-05 20:44:21 +00:00
Mehdi Amini 8eb3397a73 Degrade assertions to a warning in LTOCodeGenerator for preserved linkonce
The assertions were assuming that the linker will not ask to preserve
a global that is internal or available_externally, as it does not
really make sense. In practice this break the bootstrap of clang,
I degrade to a warning for now.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268671
2016-05-05 20:05:33 +00:00
Vitaly Buka 1df2338bb6 Revert "[ThinLTO] Emit individual index files for distributed backends"
MemorySanitizer: use-of-uninitialized-value in lib/Bitcode/Writer/BitcodeWriter.cpp:364:70
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/12544/steps/check-llvm%20msan/logs/stdio

This reverts commit 0c4a898ea550699d1b2f4fe3767251c8f9a48d52.

llvm-svn: 268660
2016-05-05 18:31:00 +00:00
Mehdi Amini 2ee1874aa8 LTOCodeGenerator: handle correctly "unnamed" symbol
This should fix the assertions in a clang LTO bootstrap we're seeing.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268658
2016-05-05 18:14:55 +00:00
Teresa Johnson 9254ebe3c0 [ThinLTO] Emit individual index files for distributed backends
Summary:
When launching ThinLTO backends in a distributed build (currently
supported in gold via the thinlto-index-only plugin option), emit
an individual index file for each backend process as described here:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098272.html

The individual index file encodes the summary and module information
required for implementing the importing/exporting decisions made
for a given module in the thin link step.
This is in place of the current mechanism that uses the combined index
to make importing decisions in each back end independently. It is an
enabler for doing global summary based optimizations in the thin link
step (which will be recorded in the individual index files), and reduces
the size of the index that must be sent to each backend process, and
the amount of work to scan it in the backends.

Rather than create entirely new ModuleSummaryIndex structures (and all
the included unique_ptrs) for each backend index file, a map is created
to record all of the GUID and summary pointers needed for a particular
index file. The IndexBitcodeWriter walks this map instead of the full
index (hiding the details of managing the appropriate summary iteration
in a new iterator subclass). This is more efficient than walking the
entire combined index and filtering out just the needed summaries during
each backend bitcode index write.

Depends on D19481.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19556

llvm-svn: 268627
2016-05-05 13:44:56 +00:00
Mehdi Amini 022b5bcb7a LTOCodeGenerator: add linkonce(_odr) to "llvm.compiler.used" when present in "MustPreserve" set
If the linker requested to preserve a linkonce function, we should
honor this even if we drop all uses.
We explicitely avoid turning them into weak_odr (unlike the first
version of this patch in r267644), because the codegen can be
different on Darwin: because of `llvm::canBeOmittedFromSymbolTable()`
we may emit the symbol as weak_def_can_be_hidden instead of
weak_definition.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268607
2016-05-05 05:14:24 +00:00
Mehdi Amini 752ffe9c5f Revert "LTOCodeGenerator: turns linkonce(_odr) into weak_(odr) when present "MustPreserve" set"
This reverts commit r267644. Turning linkonce_odr into weak_odr is
a sementic change on Darwin: because of
`llvm::canBeOmittedFromSymbolTable()` we may emit the symbol as
weak_def_can_be_hidden instead of weak_definition.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268606
2016-05-05 05:14:20 +00:00
Mehdi Amini 4b300e0ac2 ThinLTOCodeGenerator: remove useless temporary file that was emitted.
This was a remaining of a previous scheme where some IPOs were taking
place before we enter this code. This is not relevant anymore.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268605
2016-05-05 05:14:16 +00:00
Davide Italiano 164b9bc6fe [PM] Port ConstantMerge to the new pass manager.
llvm-svn: 268582
2016-05-05 00:51:09 +00:00
Davide Italiano 66228c4cf1 [IPO/GlobalDCE] Port to the new pass manager.
Differential Revision:  http://reviews.llvm.org/D19782

llvm-svn: 268425
2016-05-03 19:39:15 +00:00
Peter Collingbourne edf8432480 LTO: Don't bother trying to mangle unnamed globals, as they can't be preserved with MustPreserveSymbols.
Summary: Should fix sanitizer-windows bot.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19635

llvm-svn: 267820
2016-04-27 23:48:11 +00:00
Sjoerd Meijer 41beee6575 Clean up to avoid compiler warnings for casting away const qualifiers.
Differential Revision: http://reviews.llvm.org/D19598

llvm-svn: 267753
2016-04-27 18:35:02 +00:00
Mehdi Amini c7b950171d Revert "Support "preserving" the summary information when using setModule() API in LTOCodeGenerator"
This reverts commit r267665.
ASAN shows that there is a use of undefined value.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267668
2016-04-27 05:11:44 +00:00
Mehdi Amini 360ed847bc Support "preserving" the summary information when using setModule() API in LTOCodeGenerator
Another attempt at r267655...

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267665
2016-04-27 04:24:10 +00:00
Mehdi Amini a1b8b6cd56 Revert "Support "preserving" the summary information when using setModule() API in LTOCodeGenerator"
This reverts commit r267657, r267656, and r267655.
The test does not pass on multiple bots, I'm unsure why yet but let's unbreak them.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267664
2016-04-27 03:34:28 +00:00
Mehdi Amini e2a65fe5ec Support "preserving" the summary information when using setModule() API in LTOCodeGenerator
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267655
2016-04-27 01:46:48 +00:00
Mehdi Amini da168fbc2e LTOCodeGenerator: turns linkonce(_odr) into weak_(odr) when present "MustPreserve" set
Summary:
If the linker requested to preserve a linkonce function, we should
honor this even if we drop all uses.

Reviewers: dexonsmith

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19527

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267644
2016-04-27 00:32:02 +00:00
Justin Bogner 4563a06cee PM: Port Internalize to the new pass manager
llvm-svn: 267596
2016-04-26 20:15:52 +00:00
Mehdi Amini aa309b1a81 ThinLTOCodeGenerator: preserve linkonce when in "MustPreserved" set
If the linker specifically requested for a linkonce to be preserved,
we need to make sure we won't drop it even if all the uses in the
current module disappear.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267543
2016-04-26 10:35:01 +00:00
Justin Bogner 1a07501379 PM: Port GlobalOpt to the new pass manager
llvm-svn: 267499
2016-04-26 00:28:01 +00:00
Teresa Johnson c851d216e2 [ThinLTO] Introduce typedef for commonly-used map type (NFC)
Add a typedef for the std::map<GlobalValue::GUID, GlobalValueSummary *>
map that is passed around to identify summaries for values defined in a
particular module. This shortens up declarations in a variety of places.

llvm-svn: 267471
2016-04-25 21:09:51 +00:00
Teresa Johnson 28e457bccd [ThinLTO] Remove GlobalValueInfo class from index
Summary:
Remove the GlobalValueInfo and change the ModuleSummaryIndex to directly
reference summary objects. The info structure was there to support lazy
parsing of the combined index summary objects, which is no longer
needed and not supported.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19462

llvm-svn: 267344
2016-04-24 14:57:11 +00:00
Mehdi Amini 059464fe36 Add an internalization step to the ThinLTOCodeGenerator
Keeping as much as possible internal/private is
known to help the optimizer. Let's try to benefit from
this in ThinLTO.
Note: this is early work, but is enough to build clang (and
all the LLVM tools). I still need to write some lit-tests...

Differential Revision: http://reviews.llvm.org/D19103

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267317
2016-04-24 03:18:01 +00:00
Justin Bogner 395c2127ed PM: Port DCE to the new pass manager
Also add a very basic test, since apparently there aren't any tests
for DCE whatsoever to add the new pass version to.

llvm-svn: 267196
2016-04-22 19:40:41 +00:00
Teresa Johnson 6fb3f19959 [ThinLTO] Remove unused/incomplete lazy summary reading support (NFC)
This removes the interfaces added (and not yet complete) to support
lazy reading of summaries. This support is not expected to be needed
since we are moving to a model where the full index is only being
traversed in the thin link step, instead of the back ends.

(The second part of this that I plan to do next is remove the
GlobalValueInfo from the ModuleSummaryIndex - it was mostly needed to
support lazy parsing of summaries. The index can instead reference the
summary structures directly.)

llvm-svn: 267097
2016-04-22 01:52:00 +00:00
Mehdi Amini f95f77adf6 ThinLTO: add module caching handling.
Differential Revision: http://reviews.llvm.org/D18494

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266959
2016-04-21 05:54:23 +00:00
Mehdi Amini a71a5a6289 ThinLTO: Resolve linkonce_odr aliases just like functions
This help to streamline the process of handling importing since
we don't need to special case alias everywhere: just like
linkonce_odr function, make sure at least one alias is emitted
by turning it weak.

Differential Revision: http://reviews.llvm.org/D19308

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266958
2016-04-21 05:47:17 +00:00
Duncan P. N. Exon Smith b011ad7330 LTO: Verify the input even if optimize() isn't called
Clients may call writeMergedModules before calling optimize, or call
compileOptimized without calling optimize.  Make sure they don't sneak
past the verifier.  This adds LTOCodeGenerator::verifyMergedModuleOnce,
and calls it from writeMergedModule, optimize, and codegenOptimized.

I couldn't find a good way to test this.  I tried writing broken IR to
send into llvm-lto, but LTOCodeGenerator doesn't understand textual IR,
and assembler runs the verifier itself anyway.  Checking in
valid-but-doesn't-verify bitcode here doesn't seem valuable.

llvm-svn: 266894
2016-04-20 17:48:22 +00:00
Teresa Johnson 07c7e25718 Enable ODR uniquing of DITypes in more places
Summary:
This is a follow-on to apply Duncan's new DIType ODR uniquing from
r266549 and r266713 in more places.

Enable enableDebugTypeODRUniquing() for ThinLTO backends invoked via
libLTO, similar to the way r266549 enabled this for ThinLTO backend
threads launched from gold-plugin.

Also enable enableDebugTypeODRUniquing in opt, similar to the way
r266549 enabled this for llvm-link (on by default, can be disabled with
new -disable-debug-info-type-map option), since we may perform ThinLTO
importing from opt.

Reviewers: dexonsmith, joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19263

llvm-svn: 266746
2016-04-19 15:48:30 +00:00
Duncan P. N. Exon Smith ed8fdb2a0e IR: Rename API for enabling ODR uniquing of DITypes, NFC
As per David's review, rename everything in the new API for ODR type
uniquing of debug info.

    ensureDITypeMap  => enableDebugTypeODRUniquing
    destroyDITypeMap => disableDebugTypeODRUniquing
    hasDITypeMap     => isODRUniquingDebugTypes

llvm-svn: 266713
2016-04-19 04:55:25 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Rafael Espindola 3c1c9875b9 Keep only the splitCodegen version that takes a factory.
This makes it much easier to see that all created TargetMachines are
equivalent.

llvm-svn: 266564
2016-04-17 18:42:27 +00:00
Duncan P. N. Exon Smith 5ab2be094e IR: Use an explicit map for debug info type uniquing
Rather than relying on the structural equivalence of DICompositeType to
merge type definitions, use an explicit map on the LLVMContext that
LLParser and BitcodeReader consult when constructing new nodes.
Each non-forward-declaration DICompositeType with a non-empty
'identifier:' field is stored/loaded from the type map, and the first
definiton will "win".

This map is opt-in: clients that expect ODR types from different modules
to be merged must call LLVMContext::ensureDITypeMap.

  - Clients that just happen to load more than one Module in the same
    LLVMContext won't magically merge types.

  - Clients (like LTO) that want to continue to merge types based on ODR
    identifiers should opt-in immediately.

I have updated LTOCodeGenerator.cpp, the two "linking" spots in
gold-plugin.cpp, and llvm-link (unless -disable-debug-info-type-map) to
set this.

With this in place, it will be straightforward to remove the DITypeRef
concept (i.e., referencing types by their 'identifier:' string rather
than pointing at them directly).

llvm-svn: 266549
2016-04-17 03:58:21 +00:00
Mehdi Amini 1d30fcaccf Add SVN version to libLLVMLTO
Summary: For Incremental LTO, we need to make sure that an old
cache entry is not used when incrementally re-linking with a new
libLTO.
Adding a global LLVM_REVISION in llvm-config.h would for to
rebuild/relink the world for every "git pull"/"svn update".
So instead only libLTO is made dependent on the VCS and will
be rebuilt (and the dependent binaries relinked, i.e. as of
today: libLTO.dylib and llvm-lto).

Reviewers: beanz

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18987

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266523
2016-04-16 07:33:14 +00:00
Mehdi Amini 1aafabf752 ThinLTO: Move the ODR resolution to be based purely on the summary.
This is a requirement for the cache handling in D18494

Differential Revision: http://reviews.llvm.org/D18908

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266519
2016-04-16 07:02:16 +00:00
Mehdi Amini 8dcc8080ce ThinLTO: linkonce compile-time optimization, do not bother when there is only one input file
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266281
2016-04-14 08:46:22 +00:00
Mehdi Amini ce23e9702e Simplify LTOInternalize into UpdateLLVMCompilerUsed
It is now only doing the update to the llvm.compiler_used global.
The client has to call separately the internalization stage.
Hopefully the code is simpler to understand this way.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266174
2016-04-13 06:32:46 +00:00
Mehdi Amini 105938302a Minor cleanup in Internalize, hide helper class using anonymous namespace (NFC)
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266173
2016-04-13 06:32:29 +00:00
Mehdi Amini 16fcb418ad LTOInternalize: Use a StringSet instead of a sorted vector and a binary search query for each function
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266172
2016-04-13 06:32:04 +00:00
Mehdi Amini deee003a58 Move "ExternalSymbols" out of LTOInternalize (NFC)
This is not really related to internalization per se.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266170
2016-04-13 05:36:06 +00:00
Mehdi Amini 24d3414f06 Refactor the InternalizePass into a helper class, and expose it through a public free function (NFC)
There is really no reason to require to instanciate a pass manager to
internalize.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266167
2016-04-13 05:25:08 +00:00
Mehdi Amini 4078709957 Refactor Internalization pass to use as a callback instead of a StringSet (NFC)
This will save a bunch of copies / initialization of intermediate
datastructure, and (hopefully) simplify the code.

This also abstract the symbol preservation mechanism outside of the
Internalization pass into the client code, which is not forced
to keep a map of strings for instance (ThinLTO will prefere hashes).

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266163
2016-04-13 04:20:32 +00:00
Mehdi Amini 3dfc952e83 LTOInternalize: Fix member type, should be a reference and not a copy
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266153
2016-04-12 23:58:30 +00:00
Stephan Bergmann a6ced02a67 Avoid GCC -fpermissive error about llvm::Mangler hidden by member named Mangler
llvm-svn: 266049
2016-04-12 08:23:44 +00:00
Mehdi Amini f59f2bb1b5 Refactor the Internalize stage of libLTO in a separate file (NFC)
This is intended to be shared by the ThinLTOCodeGenerator.

Note that there is a change in the way the verifier is run, previously
it was ran as a Pass on the merged module during internalization.
While now the verifier is called explicitely on the merged module
outside of the internalize "pass pipeline".

What remains strange in the API is the fact that `DisableVerify` in
the API does not disable this initial verifier.

Differential Revision: http://reviews.llvm.org/D19000

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266047
2016-04-12 06:34:10 +00:00
Teresa Johnson 2d5487cf44 [ThinLTO] Move summary computation from BitcodeWriter to new pass
Summary:
This is the first step in also serializing the index out to LLVM
assembly.

The per-module summary written to bitcode is moved out of the bitcode
writer and to a new analysis pass (ModuleSummaryIndexWrapperPass).
The pass itself uses a new builder class to compute index, and the
builder class is used directly in places where we don't have a pass
manager (e.g. llvm-as).

Because we are computing summaries outside of the bitcode writer, we no
longer can use value ids created by the bitcode writer's
ValueEnumerator. This required changing the reference graph edge type
to use a new ValueInfo class holding a union between a GUID (combined
index) and Value* (permodule index). The Value* are converted to the
appropriate value ID during bitcode writing.

Also, this enables removal of the BitWriter library's dependence on the
Analysis library that was previously required for the summary computation.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18763

llvm-svn: 265941
2016-04-11 13:58:45 +00:00
Evgeniy Stepanov 268826a287 [gold] Save bitcode for module partitions (save-temps + split codegen).
llvm-svn: 265583
2016-04-06 18:32:13 +00:00
Teresa Johnson 3c35e0999b Clean up calls to WriteBitcodeToFile (NFC)
Remove a default parameter value being passed unnecessarily, which
also reduces the changes required when this parameter is changed in
D18763.

Document the remaining non-default bool value passed for another
parameter.

llvm-svn: 265348
2016-04-04 21:19:31 +00:00
Mehdi Amini 024a79f780 Revert "ThinLTO: add module caching handling."
This reverts commit r265214, unintentionally commited.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265216
2016-04-02 05:08:18 +00:00
Mehdi Amini 2cd609482d ThinLTO: add module caching handling.
Reviewers: tejohnson

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18494

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265214
2016-04-02 05:07:08 +00:00
Hans Wennborg fa6e414eef Fix -Wpedantic warning about extra semi-colon
llvm-svn: 265204
2016-04-02 01:03:41 +00:00
Mehdi Amini 5a2e5d324e ThinLTO: special handling for LinkOnce functions
These function can be dropped by the compiler if they are no longer
referenced in the current module. However there is a change that
another module is still referencing them because of the import.

Multiple solutions can be used:

- Always import LinkOnce when a caller is imported. This ensure that
  every module with a call to a LinkOnce has the definition and will
  be able to emit it if it emits the call.
- Turn the LinkOnce into Weak, so that it is always emitted.
- Turn all LinkOnce into available_externally and come back after all
  modules are codegen'ed to emit only one copy of the linkonce, when
  there is still a reference to it.

This patch implement the second option, with am optimization that
only *one* module will turn the LinkOnce into Weak, while the others
will turn it into available_externally, so that there is exactly one
copy emitted for the whole compilation.

http://reviews.llvm.org/D18346

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265190
2016-04-01 21:53:50 +00:00
Mehdi Amini 215d59e7b0 ThinLTO: move ObjCARCContractPass in the CodeGen pipeline
This is to be coherent with Full LTO.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265118
2016-04-01 08:22:59 +00:00
Mehdi Amini 43b657b5c7 Add a libLTO API to stop/restart ThinLTO between optimizations and CodeGen
This allows the linker to instruct ThinLTO to perform only the
optimization part or only the codegen part of the process.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265113
2016-04-01 06:47:02 +00:00
Mehdi Amini 01e321306b ThinLTO: use the callgraph from the combined index to drive the FunctionImporter
Summary:
Now that the summary contains the full reference/call graph, we can
replace the existing function importer that loads and inspect the IR
to iteratively walk the call graph by a traversal based purely on the
summary information. Decouple the actual importing decision from any
IR manipulation.

Reviewers: tejohnson

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18343

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 264503
2016-03-26 05:40:34 +00:00
Teresa Johnson 26ab5772b0 [ThinLTO] Renaming of function index to module summary index (NFC)
(Resubmitting after fixing missing file issue)

With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.

A companion clang patch will immediately succeed this patch to reflect
this renaming.

llvm-svn: 263513
2016-03-15 00:04:37 +00:00
Teresa Johnson cec0cae313 Revert "[ThinLTO] Renaming of function index to module summary index (NFC)"
This reverts commit r263490. Missed a file.

llvm-svn: 263493
2016-03-14 21:18:10 +00:00
Teresa Johnson 892920b358 [ThinLTO] Renaming of function index to module summary index (NFC)
With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.

A companion clang patch will immediately succeed this patch to reflect
this renaming.

llvm-svn: 263490
2016-03-14 21:05:56 +00:00
Teresa Johnson 76a1c1d0ba [ThinLTO] Support for reference graph in per-module and combined summary.
Summary:
This patch adds support for including a full reference graph including
call graph edges and other GV references in the summary.

The reference graph edges can be used to make importing decisions
without materializing any source modules, can be used in the plugin
to make file staging decisions for distributed build systems, and is
expected to have other uses.

The call graph edges are recorded in each function summary in the
bitcode via a list of <CalleeValueIds, StaticCount> tuples when no PGO
data exists, or <CalleeValueId, StaticCount, ProfileCount> pairs when
there is PGO, where the ValueId can be mapped to the function GUID via
the ValueSymbolTable. In the function index in memory, the call graph
edges reference the target via the CalleeGUID instead of the
CalleeValueId.

The reference graph edges are recorded in each summary record with a
list of referenced value IDs, which can be mapped to value GUID via the
ValueSymbolTable.

Addtionally, a new summary record type is added to record references
from global variable initializers. A number of bitcode records and data
structures have been renamed to reflect the newly expanded scope of the
summary beyond functions. More cleanup will follow.

Reviewers: joker.eph, davidxl

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17212

llvm-svn: 263275
2016-03-11 18:52:24 +00:00
Chandler Carruth 89c45a162f [PM] Port GVN to the new pass manager, wire it up, and teach a couple of
tests to run GVN in both modes.

This is mostly the boring refactoring just like SROA and other complex
transformation passes. There is some trickiness in that GVN's
ValueNumber class requires hand holding to get to compile cleanly. I'm
open to suggestions about a better pattern there, but I tried several
before settling on this. I was trying to balance my desire to sink as
much implementation detail into the source file as possible without
introducing overly many layers of abstraction.

Much like with SROA, the design of this system is made somewhat more
cumbersome by the need to support both pass managers without duplicating
the significant state and logic of the pass. The same compromise is
struck here.

I've also left a FIXME in a doxygen comment as the GVN pass seems to
have pretty woeful documentation within it. I'd like to submit this with
the FIXME and let those more deeply familiar backfill the information
here now that we have a nice place in an interface to put that kind of
documentaiton.

Differential Revision: http://reviews.llvm.org/D18019

llvm-svn: 263208
2016-03-11 08:50:55 +00:00
Mehdi Amini 1592cb9aa1 Rename -discard-value-names into -lto-discard-value-names in libLLVMLTO
This is avoiding a naming conflict with opt and llc.
While opt and llc don't link to LTO usually, users that are building a
monolithic libLLVM.dylib and linking the tools to it would have a
runtime error because of the duplicate cl::opt registration.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 263127
2016-03-10 17:06:52 +00:00
Mehdi Amini 09b4a8daa3 Add a flag to the LLVMContext to disable name for Value other than GlobalValue
Summary:
This is intended to be a performance flag, on the same level as clang
cc1 option "--disable-free". LLVM will never initialize it by default,
it will be up to the client creating the LLVMContext to request this
behavior. Clang will do it by default in Release build (just like
--disable-free).

"opt" and "llc" can opt-in using -disable-named-value command line
option.

When performing LTO on llvm-tblgen, the initial merging of IR peaks
at 92MB without this patch, and 86MB after this patch,setNameImpl()
drops from 6.5MB to 0.5MB.
The total link time goes from ~29.5s to ~27.8s.

Compared to a compile-time flag (like the IRBuilder one), it performs
very close. I profiled on SROA and obtain these results:

 420ms with IRBuilder that preserve name
 372ms with IRBuilder that strip name
 375ms with IRBuilder that preserve name, and a runtime flag to strip

Reviewers: chandlerc, dexonsmith, bogner

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17946

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 263086
2016-03-10 01:28:54 +00:00
Mehdi Amini 7c4a1a8d48 libLTO: add a ThinLTOCodeGenerator on the model of LTOCodeGenerator.
This is intended to provide a parallel (threaded) ThinLTO scheme
for linker plugin use through the libLTO C API.

The intent of this patch is to provide a first implementation as a
proof-of-concept and allows linker to start supporting ThinLTO by
definiing the libLTO C API. Some part of the libLTO API are left
unimplemented yet. Following patches will add support for these.

The current implementation can link all clang/llvm binaries.

Differential Revision: http://reviews.llvm.org/D17066

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 262977
2016-03-09 01:37:22 +00:00
David Blaikie bcb1c7e369 Fix some warnings a bit harder/different
This is an alternate fix to 262378 and a fix to a pessimizing-move
warning.

llvm-svn: 262390
2016-03-01 20:41:17 +00:00