Commit Graph

652 Commits

Author SHA1 Message Date
Steven Wu ec53c89fde [ThinLTOCodeGenerator] Avoid Rehash StringMap in ThreadPool
Summary:
During threaded thinLTO, it is possible that the entry for current
module doesn't exist in StringMaps (like ExportLists, ResolvedODR,
etc.). Using operator[] might trigger a rehash for the StringMap, which
might happen on multiple threads at the same time.

rdar://problem/43846199

Reviewers: tejohnson, mehdi_amini, kromanova, pcc

Reviewed By: tejohnson

Subscribers: dang, inglorion, eraman, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D52049

llvm-svn: 342263
2018-09-14 19:38:21 +00:00
Steven Wu cf90203b0b [ThinLTO] Fix memory corruption in ThinLTOCodeGenerator when CodeGenOnly was specified
Summary:
Issue occurs when doing ThinLTO with CodeGenOnly flag.
TMBuilder.TheTriple is assigned to by multiple threads in an unsafe way resulting in double-free of std::string memory.

Pseudocode:
if (CodeGenOnly) {
  // Perform only parallel codegen and return.
  ThreadPool Pool;
  int count = 0;
  for (auto &ModuleBuffer : Modules) {
    Pool.async([&](int count) {
    ...
      /// Now call OutputBuffer = codegen(*TheModule);
      /// Which turns into initTMBuilder(moduleTMBuilder, Triple(TheModule.getTargetTriple()));
      /// Which turns into

      TMBuilder.TheTriple = std::move(TheTriple);   // std::string = "....."
      /// So, basically std::string assignment to same string on multiple threads = memory corruption

  }

  return;
}

Patch by Alex Borcan

Reviewers: llvm-commits, steven_wu

Reviewed By: steven_wu

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D51651

llvm-svn: 341422
2018-09-04 22:54:17 +00:00
Fangrui Song f78650a8de Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293
2018-07-30 19:41:25 +00:00
Bob Haarman eae4742d81 [LTO] Don't internalize declarations
Summary:
Some links were failing with "Global is external, but doesn't have
external or weak linkage!" in ThinLTO builds with debug
information. This happened when we elide the body of a global that is
referenced by debug info. This results in a declaration, which we
would then internalize - but declarations cannot be internal. This
change avoids the problem by not internalizing these declarations.

Fixes PR38046.

Reviewers: pcc, tejohnson

Subscribers: mehdi_amini, aprantl, hiraditya, JDevlieghere, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D49777

llvm-svn: 338100
2018-07-27 05:40:29 +00:00
Teresa Johnson b963c0b658 [LTO] Handle __imp_ (dllimport) symbols consistently with lld
Summary:
Similar to what lld already does for dllimport symbols which are
prefaced with __imp_ (see lld patch r240620), strip off the __imp_
prefix in LTO. Otherwise we can get 2 separate GlobalResolution for
a single symbol, the dllimport declaration, and the definition, which
leads to incorrect LTO handling.

Fixes PR38105.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D49138

llvm-svn: 337762
2018-07-23 22:33:57 +00:00
Teresa Johnson 28023dbed7 [ThinLTO] Enable ThinLTO WholeProgramDevirt and LowerTypeTests in new PM
Summary:
Enable these passes for CFI and WPD in ThinLTO and LTO with the new pass
manager. Add a couple of tests for both PMs based on the clang tests
tools/clang/test/CodeGen/thinlto-distributed-cfi*.ll, but just test
through llvm-lto2 and not with distributed ThinLTO.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D49429

llvm-svn: 337461
2018-07-19 14:51:32 +00:00
Teresa Johnson d68935c5ac Restore "[ThinLTO] Ensure we always select the same function copy to import"
This reverts commit r337081, therefore restoring r337050 (and fix in
r337059), with test fix for bot failure described after the original
description below.

In order to always import the same copy of a linkonce function,
even when encountering it with different thresholds (a higher one then a
lower one), keep track of the summary we decided to import.
This ensures that the backend only gets a single definition to import
for each GUID, so that it doesn't need to choose one.

Move the largest threshold the GUID was considered for import into the
current module out of the ImportMap (which is part of a larger map
maintained across the whole index), and into a new map just maintained
for the current module we are computing imports for. This saves some
memory since we no longer have the thresholds maintained across the
whole index (and throughout the in-process backends when doing a normal
non-distributed ThinLTO build), at the cost of some additional
information being maintained for each invocation of ComputeImportForModule
(the selected summary pointer for each import).

There is an additional map lookup for each callee being considered for
importing, however, this was able to subsume a map lookup in the
Worklist iteration that invokes computeImportForFunction. We also are
able to avoid calling selectCallee if we already failed to import at the
same or higher threshold.

I compared the run time and peak memory for the SPEC2006 471.omnetpp
benchmark (running in-process ThinLTO backends), as well as for a large
internal benchmark with a distributed ThinLTO build (so just looking at
the thin link time/memory). Across a number of runs with and without
this change there was no significant change in the time and memory.

(I tried a few other variations of the change but they also didn't
improve time or peak memory).

The new commit removes a test that no longer makes sense
(Transforms/FunctionImport/hotness_based_import2.ll), as exposed by the
reverse-iteration bot. The test depends on the order of processing the
summary call edges, and actually depended on the old problematic
behavior of selecting more than one summary for a given GUID when
encountered with different thresholds. There was no guarantee even
before that we would eventually pick the linkonce copy with the hottest
call edges, it just happened to work with the test and the old code, and
there was no guarantee that we would end up importing the selected
version of the copy that had the hottest call edges (since the backend
would effectively import only one of the selected copies).

Reviewers: davidxl

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D48670

llvm-svn: 337184
2018-07-16 15:30:27 +00:00
Teresa Johnson b78c5d0602 Revert "[ThinLTO] Ensure we always select the same function copy to import"
This reverts commits r337050 and r337059. Caused failure in
reverse-iteration bot that needs more investigation.

llvm-svn: 337081
2018-07-14 01:45:49 +00:00
Teresa Johnson d94c0594d9 [ThinLTO] Ensure we always select the same function copy to import
In order to always import the same copy of a linkonce function,
even when encountering it with different thresholds (a higher one then a
lower one), keep track of the summary we decided to import.
This ensures that the backend only gets a single definition to import
for each GUID, so that it doesn't need to choose one.

Move the largest threshold the GUID was considered for import into the
current module out of the ImportMap (which is part of a larger map
maintained across the whole index), and into a new map just maintained
for the current module we are computing imports for. This saves some
memory since we no longer have the thresholds maintained across the
whole index (and throughout the in-process backends when doing a normal
non-distributed ThinLTO build), at the cost of some additional
information being maintained for each invocation of ComputeImportForModule
(the selected summary pointer for each import).

There is an additional map lookup for each callee being considered for
importing, however, this was able to subsume a map lookup in the
Worklist iteration that invokes computeImportForFunction. We also are
able to avoid calling selectCallee if we already failed to import at the
same or higher threshold.

I compared the run time and peak memory for the SPEC2006 471.omnetpp
benchmark (running in-process ThinLTO backends), as well as for a large
internal benchmark with a distributed ThinLTO build (so just looking at
the thin link time/memory). Across a number of runs with and without
this change there was no significant change in the time and memory.

(I tried a few other variations of the change but they also didn't
improve time or peak memory).

Reviewers: davidxl

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D48670

llvm-svn: 337050
2018-07-13 21:35:51 +00:00
Teresa Johnson c0320ef47b [ThinLTO] Use std::map to get determistic imports files
Summary:
I noticed that the .imports files emitted for distributed ThinLTO
backends do not have consistent ordering. This is because StringMap
iteration order is not guaranteed to be deterministic. Since we already
have a std::map with this information, used when emitting the individual
index files (ModuleToSummariesForIndex), use it for the imports files as
well.

This issue is likely causing some unnecessary rebuilds of the ThinLTO
backends in our distributed build system as the imports files are inputs
to those backends.

Reviewers: pcc, steven_wu, mehdi_amini

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D48783

llvm-svn: 336721
2018-07-10 20:06:04 +00:00
Andrew Ng 089303d8ff [ThinLTO] Update ThinLTO cache file atimes when on Windows
ThinLTO cache file access times are used for expiration based pruning
and since Vista, file access times are not updated by Windows by
default:

https://blogs.technet.microsoft.com/filecab/2006/11/07/disabling-last-access-time-in-windows-vista-to-improve-ntfs-performance

This means on Windows, cache files are currently being pruned from
creation time. This change manually updates cache files that are
accessed by ThinLTO, when on Windows.

Patch by Owen Reynolds.

Differential Revision: https://reviews.llvm.org/D47266

llvm-svn: 336276
2018-07-04 14:17:10 +00:00
Peter Collingbourne 881ba10465 LTO: Keep file handles open for memory mapped files.
On Windows we've observed that if you open a file, write to it, map it into
memory and close the file handle, the contents of the memory mapping can
sometimes be incorrect. That was what we did when adding an entry to the
ThinLTO cache using the TempFile and MemoryBuffer classes, and it was causing
intermittent build failures on Chromium's ThinLTO bots on Windows. More
details are in the associated Chromium bug (crbug.com/786127).

We can prevent this from happening by keeping a handle to the file open while
the mapping is active. So this patch changes the mapped_file_region class to
duplicate the file handle when mapping the file and close it upon unmapping it.

One gotcha is that the file handle that we keep open must not have been
created with FILE_FLAG_DELETE_ON_CLOSE, as otherwise the operating system
will prevent other processes from opening the file. We can achieve this
by avoiding the use of FILE_FLAG_DELETE_ON_CLOSE altogether.  Instead,
we use SetFileInformationByHandle with FileDispositionInfo to manage the
delete-on-close bit. This lets us remove the hack that we used to use to
clear the delete-on-close bit on a file opened with FILE_FLAG_DELETE_ON_CLOSE.

A downside of using SetFileInformationByHandle/FileDispositionInfo as
opposed to FILE_FLAG_DELETE_ON_CLOSE is that it prevents us from using
CreateFile to open the file while the flag is set, even within the same
process. This doesn't seem to matter for almost every client of TempFile,
except for LockFileManager, which calls sys::fs::create_link to create a
hard link from the lock file, and in the process of doing so tries to open
the file. To prevent this change from breaking LockFileManager I changed it
to stop using TempFile by effectively reverting r318550.

Differential Revision: https://reviews.llvm.org/D48051

llvm-svn: 334630
2018-06-13 18:03:14 +00:00
Teresa Johnson 4ffc3e7834 [ThinLTO] Rename index IsAnalysis flag to HaveGVs (NFC)
With the upcoming patch to add summary parsing support, IsAnalysis would
be true in contexts where we are not performing module summary analysis.
Rename to the more specific and approprate HaveGVs, which is essentially
what this flag is indicating.

llvm-svn: 334140
2018-06-06 22:22:01 +00:00
Peter Collingbourne 3aa30e8062 IRGen: Write .dwo files when -split-dwarf-file is used together with -fthinlto-index.
Differential Revision: https://reviews.llvm.org/D47597

llvm-svn: 333677
2018-05-31 18:25:59 +00:00
Peter Collingbourne 274c4f7ab4 Fix a make_unique ambiguity.
llvm-svn: 332889
2018-05-21 20:56:28 +00:00
Peter Collingbourne c5a9765cea LTO: Replace split dwarf implementation that uses objcopy with one that uses direct emission.
Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47091

llvm-svn: 332884
2018-05-21 20:26:49 +00:00
Peter Collingbourne 9a45114b3c CodeGen: Add a dwo output file argument to addPassesToEmitFile and hook it up to dwo output.
Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47089

llvm-svn: 332881
2018-05-21 20:16:41 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Teresa Johnson 81d9207317 [LTO] Handle Task=-1 passed to addSaveTemps
Summary:
This change is necessary for D46464, which will pass -1 as the Task
ID for distributed backends, so that the save temps files don't end
up with "4294967295" in their path. For distributed back ends, when -1
is passed, don't append any Task ID.

An existing test (tools/clang/test/CodeGen/thinlto_backend.ll) will
fail without this change after D46464.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D46488

llvm-svn: 331591
2018-05-05 14:37:20 +00:00
Teresa Johnson b77ab0966e [LTO] Allow pass remarks with hotness to be set when emitting to stderr
Summary:
Set setDiagnosticsHotnessRequested before the early exit check for a
diagnostic output file, so that pass remarks with hotness works when
emitting pass remarks to stderr (e.g. via -pass-remarks=.).

Also fix the llvm-lto2 diagnistic handler so that it only calls exit(1)
when the diagnistic is an error type. Otherwise the new test invocation
of llvm-lto2 with -pass-remarks causes it to fail. The new code is
consistent with the diagnostic handler elsewhere (e.g. on the
LLVMContext).

Reviewers: pcc, davide

Subscribers: fhahn, mehdi_amini, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D46387

llvm-svn: 331569
2018-05-04 23:59:34 +00:00
Teresa Johnson 85cc298c1a [ThinLTO] Add support for optimization remarks to thinBackend
Summary:
Support was added to the regular LTO backend, but not thinBackend.
This patch adds that support.

Reviewers: pcc, davide

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D46376

llvm-svn: 331481
2018-05-03 20:24:12 +00:00
Nico Weber 432a38838d IWYU for llvm-config.h in llvm, additions.
See r331124 for how I made a list of files missing the include.
I then ran this Python script:

    for f in open('filelist.txt'):
        f = f.strip()
        fl = open(f).readlines()

        found = False
        for i in xrange(len(fl)):
            p = '#include "llvm/'
            if not fl[i].startswith(p):
                continue
            if fl[i][len(p):] > 'Config':
                fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
                found = True
                break
        if not found:
            print 'not found', f
        else:
            open(f, 'w').write(''.join(fl))

and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.

No intended behavior change.

llvm-svn: 331184
2018-04-30 14:59:11 +00:00
Florian Hahn d4332eb3b7 [LTO] Add stats-file option to LTO/Config.h.
This patch adds a StatsFile option to LTO/Config.h and updates both
LLVMGold and llvm-lto2 to set it.

Reviewers: MatzeB, tejohnson, espindola

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D45531

llvm-svn: 330411
2018-04-20 10:18:36 +00:00
Weiming Zhao 79f2d093dd Rename ObjectMemoryBuffer to SmallVectorMemoryBuffer; NFCI
Summary: As discussed in https://reviews.llvm.org/D45606, it makes more sense to name the class as SmallVectorMemoryBuffer

Reviewers: bkramer, dblaikie

Reviewed By: dblaikie

Subscribers: mehdi_amini, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D45661

llvm-svn: 330107
2018-04-16 03:44:03 +00:00
Weiming Zhao 7c16977a8f NFC: Move ObjectMemoryBuffer to support
Summary:
Since the class is used by both MCJIT and LTO, it makes more sense to move it to Support lib.
This is a follow up patch to r329929 and https://reviews.llvm.org/D45244

Reviewers: bkramer, dblaikie

Reviewed By: bkramer

Subscribers: mehdi_amini, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D45606

llvm-svn: 330093
2018-04-15 05:17:14 +00:00
Mandeep Singh Grang 5416af7af6 [LTO] Change std::sort to llvm::sort in response to r327219
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.

To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.

Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer D44363 for a list of all the required patches.

Reviewers: pcc, mehdi_amini, ruiu

Reviewed By: ruiu

Subscribers: ruiu, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D45137

llvm-svn: 330053
2018-04-13 19:12:20 +00:00
Yunlian Jiang bd200b9ff6 Enable debug fission for thinLTO linked via gold-plugin
Summary: This enables debug fission on implicit ThinLTO when linked with gold. It will put the .dwo files in a directory specified by user. 

Reviewers: tejohnson, pcc, dblaikie

Reviewed By: pcc

Subscribers: JDevlieghere, mehdi_amini, inglorion

Differential Revision: https://reviews.llvm.org/D44792

llvm-svn: 329988
2018-04-13 05:03:28 +00:00
Weiming Zhao 1bd40005ba Add missing vtable anchors
Summary: This patch adds anchor() for MemoryBuffer, raw_fd_ostream, RTDyldMemoryManager, SectionMemoryManager, etc.

Reviewers: jlebar, eli.friedman, dblaikie

Reviewed By: dblaikie

Subscribers: mehdi_amini, mgorny, dblaikie, weimingz, llvm-commits

Differential Revision: https://reviews.llvm.org/D45244

llvm-svn: 329861
2018-04-11 23:09:20 +00:00
Ekaterina Romanova 0b01dfbba6 Prevent data races in concurrent ThinLTO processes.
Make sure ThinLTO with caching doesn't use non-atomic writes to the cache file (to prevent data races and cache files corruption).

1. Place temp file to the same place where the caching directory is (instead of creating it the directory pointed to by TMP/TEMP variable). This will help to prevent using non-atomic rename and falling back to non-atomic "direct" write to the cache file.
2. if rename failed do not write to the cache file directly (direct write to the file is non-atomic and could cause data race conditions).
3. if cache file doesn't exist (e.g., because 'rename' failed or because some other reasons), bypass using the cache altogether.

Differential Revision:  https://reviews.llvm.org/D45076

llvm-svn: 328904
2018-03-30 21:35:42 +00:00
David Blaikie 6054e650ff Move TargetLoweringObjectFile from CodeGen to Target to fix layering
It's implemented in Target & include from other Target headers, so the
header should be in Target.

llvm-svn: 328392
2018-03-23 23:58:19 +00:00
David Blaikie 8820929011 Sink Analysis/ObjectUtil(canBeOmittedFromSymbolTable) into IR so it can be legitimately be used by Object/IRSymtab
llvm-svn: 328135
2018-03-21 19:23:45 +00:00
Adam Nemet ade40dd3c8 [LTO] Return proper error object rather than null LTOModule
This caused a crash in LTOModule::createInLocalContext.

rdar://37926841

llvm-svn: 327359
2018-03-13 04:37:01 +00:00
Bob Haarman fb2d342299 Revert "[LTO] Support filtering by hotness threshold"
This reverts commit 1f3bd185c53beb6aa68446974b7e80837abd6ef0 (r326107)
because it fails
ThinLTO/X86/diagnostic-handler-remarks-with-hotness.ll.

llvm-svn: 326975
2018-03-08 01:13:10 +00:00
Adam Nemet b4ce3573c4 [LTO] Support filtering by hotness threshold
This wires up -pass-remarks-hotness-threshold to LTO and ThinLTO.

Next is to change the clang driver to pass this
with -fdiagnostics-hotness-threshold.

Differential Revision: https://reviews.llvm.org/D41465

llvm-svn: 326107
2018-02-26 18:37:45 +00:00
Vitaly Buka a139b69e12 [ThinLTO] Always create linked objects file for --thinlto-index-only=
Summary:
ThinLTO indexing may decide to skip all objects. If we don't write something to
the list build system may consider this as failure or linker can reuse a file
from the previews build.

Reviewers: pcc, tejohnson

Subscribers: mehdi_amini, inglorion, eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D43415

llvm-svn: 325819
2018-02-22 19:06:15 +00:00
Teresa Johnson a344fd3db6 [LTO] Remove unused Path parameter to AddBufferFn
Summary:
With D43396, no clients use the Path parameter anymore.

Depends on D43396.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D43400

llvm-svn: 325619
2018-02-20 20:21:53 +00:00
Charles Saternos b040fcc693 [ThinLTO] Add GraphTraits for FunctionSummaries
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.

Third attempt - moved function from lambda to static function due to build failures.

llvm-svn: 325506
2018-02-19 15:14:50 +00:00
Simon Pilgrim 0efed32577 Revert: [llvm] r325448 - [ThinLTO] Add GraphTraits for FunctionSummaries
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.

Second attempt, since last patch caused stage2 build to fail (now using function_ref rather than std::function).

Reverted due to buildbot failures

llvm-svn: 325454
2018-02-18 00:01:36 +00:00
Charles Saternos 35878ee7a4 [ThinLTO] Add GraphTraits for FunctionSummaries
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.

Second attempt, since last patch caused stage2 build to fail (now using function_ref rather than std::function).

llvm-svn: 325448
2018-02-17 21:39:24 +00:00
Rafael Espindola 6a86e25d90 Pass a reference to a module to the bitcode writer.
This simplifies most callers as they are already using references or
std::unique_ptr.

llvm-svn: 325155
2018-02-14 19:11:32 +00:00
Volodymyr Sapsai 2ad768bb13 Revert "[ThinLTO] Add GraphTraits for FunctionSummaries"
It caused assertion failure
Assertion failed: (!DD.IsLambda && !MergeDD.IsLambda && "faked up lambda definition?"), function MergeDefinitionData, file /Users/buildslave/jenkins/workspace/clang-stage1-configure-RA/llvm/tools/clang/lib/Serialization/ASTReaderDecl.cpp, line 1675.

on the second stage build bots.

llvm-svn: 324932
2018-02-12 20:43:31 +00:00
Charles Saternos d3e7d19f59 [ThinLTO] Add GraphTraits for FunctionSummaries
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.

llvm-svn: 324854
2018-02-11 22:06:20 +00:00
Peter Collingbourne 7f1a5ba12a LTO: Include live bit in ThinLTO cache key.
As of r323633, this bit started controlling whether symbol definitions
appear in object files, and it also became sensitive to the prevailing
bit, so it needs to be included in the key.

Differential Revision: https://reviews.llvm.org/D43109

llvm-svn: 324711
2018-02-09 05:58:55 +00:00
Teresa Johnson 791c98e4c8 [ThinLTO] Remove dead and dropped symbol declarations when possible
Summary:
Removing the dropped symbols will prevent indirect call promotion in the
ThinLTO Backend from adding a new reference to a symbol, which can
result in linker unsats. This can happen when we compile with a sample
profile collected from one binary by used for another, which may have
profiled targets that aren't used in the new binary.

Note that until dropDeadSymbols handles variables and aliases (in
progress), we may not be able to remove the declaration and can still
have an issue.

Reviewers: grimar, davidxl

Subscribers: mehdi_amini, inglorion, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D42816

llvm-svn: 324299
2018-02-06 00:43:39 +00:00
Peter Collingbourne 3fe815d125 LTO: Also include dso-local bit for calls in ThinLTO cache key.
Differential Revision: https://reviews.llvm.org/D42934

llvm-svn: 324291
2018-02-05 23:46:32 +00:00
Peter Collingbourne b4edfb9af9 LTO: Include dso-local bit in ThinLTO cache key.
Differential Revision: https://reviews.llvm.org/D42713

llvm-svn: 324253
2018-02-05 17:17:51 +00:00
Teresa Johnson 5a95c47730 [ThinLTO] Convert dead alias to declarations
Summary:
This complements the fixes in r323633 and r324075 which drop the
definitions of dead functions and variables, respectively.

Fixes PR36208.

Reviewers: grimar, rafael

Subscribers: mehdi_amini, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D42856

llvm-svn: 324242
2018-02-05 15:44:27 +00:00
George Rimar f5de271a92 [LTO] - Simplify. NFC.
llvm-svn: 324076
2018-02-02 12:21:26 +00:00
George Rimar 76c5fae2a0 [ThinLTO] - Fix for "ThinLTO inlines variables that should be discarded".
This fixes PR36187.

Patch teaches ThinLTO to drop non-prevailing variables, 
just like we recently did for functions (in r323633).

Differential revision: https://reviews.llvm.org/D42798

llvm-svn: 324075
2018-02-02 12:17:33 +00:00
Vitaly Buka 59baf73a4d [ThinLTO/gold] Write empty imports even for modules with symbols
Summary: ThinLTO may skip object for other reasons, e.g. if there is no summary.

Reviewers: pcc, eugenis

Subscribers: mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D42514

llvm-svn: 323818
2018-01-30 21:19:26 +00:00
George Rimar eaf5172ca6 [ThinLTO] - Stop internalizing and drop non-prevailing symbols.
Implementation marks non-prevailing symbols as not live in the summary.
Then them are dropped in backends.

Fixes https://bugs.llvm.org/show_bug.cgi?id=35938

Differential revision: https://reviews.llvm.org/D42107

llvm-svn: 323633
2018-01-29 08:03:30 +00:00
George Rimar d328365b2e [LTO] - Introduce GlobalResolution::Prevailing flag.
It is NFC refactoring change that will make
D42107 a bit smaller.

Differential revision: https://reviews.llvm.org/D42528

llvm-svn: 323444
2018-01-25 17:23:27 +00:00
Amjad Aboud f1f57a3137 Another try to commit 323321 (aggressive instruction combine).
llvm-svn: 323416
2018-01-25 12:06:32 +00:00
Rafael Espindola 349fe0aa87 Simplify. NFC.
Thanks to Teresa Johnson for the suggestion.

llvm-svn: 323365
2018-01-24 19:11:24 +00:00
Amjad Aboud d53504e379 Reverted 323321.
llvm-svn: 323326
2018-01-24 14:48:49 +00:00
Amjad Aboud e4453233d7 [InstCombine] Introducing Aggressive Instruction Combine pass (-aggressive-instcombine).
Combine expression patterns to form expressions with fewer, simple instructions.
This pass does not modify the CFG.

For example, this pass reduce width of expressions post-dominated by TruncInst
into smaller width when applicable.

It differs from instcombine pass in that it contains pattern optimization that
requires higher complexity than the O(1), thus, it should run fewer times than
instcombine pass.

Differential Revision: https://reviews.llvm.org/D38313

llvm-svn: 323321
2018-01-24 12:42:42 +00:00
Nico Weber 1c7c45688c Introduce errorToBool() helper and use it.
errorToBool() converts an Error to a bool and puts the Error in a checked
state.  No behavior change.

https://reviews.llvm.org/D42422

llvm-svn: 323238
2018-01-23 19:03:13 +00:00
Eugene Leviant 28d8a49f42 [ThinLTO] Re-commit of dot dumper after test fix
llvm-svn: 323116
2018-01-22 13:35:40 +00:00
Eugene Leviant 72b9bdb71a Temporarily revert r323062 to investigate buildbot failures
llvm-svn: 323065
2018-01-21 10:22:19 +00:00
Eugene Leviant 453c976a63 [ThinLTO] Implement summary visualizer
Differential revision: https://reviews.llvm.org/D41297

llvm-svn: 323062
2018-01-21 07:27:32 +00:00
Rafael Espindola 8a1ca67461 Don't drop dso_local in LTO.
LTO sets dso_local as an optimization, so don't clear it.

This avoid clearing it from undefined hidden symbols, which would then
fail the verifier.

llvm-svn: 322814
2018-01-18 05:38:43 +00:00
George Rimar 2421b6fa5c [ThinLTO] - Remove code duplication. NFC.
Refactors 3 copies of isExpected.
Splitted from D42107.

llvm-svn: 322627
2018-01-17 10:33:05 +00:00
Benjamin Kramer 3afb1736f2 [LTO] Simplify code. No functionality change intended.
llvm-svn: 321531
2017-12-28 18:31:19 +00:00
Benjamin Kramer 3a13ed60ba Avoid int to string conversion in Twine or raw_ostream contexts.
Some output changes from uppercase hex to lowercase hex, no other functionality change intended.

llvm-svn: 321526
2017-12-28 16:58:54 +00:00
Dimitry Andric e4f5d01033 Fix more inconsistent line endings. NFC.
llvm-svn: 321016
2017-12-18 19:46:56 +00:00
Vitaly Buka a5376f393e [LTO] Make processing of combined module more consistent
Summary:
1. Use stream 0 only for combined module. Previously if combined module was not
processes ThinLTO used the stream for own output. However small changes in input,
could trigger combined module  and shuffle outputs making life of llvm::LTO harder.

2. Always process combined module and write output to stream 0. Processing empty
combined module is cheap and allows llvm::LTO users to avoid implementing processing
which is already done in llvm::LTO.

Subscribers: mehdi_amini, inglorion, eraman, hiraditya

Differential Revision: https://reviews.llvm.org/D41267

llvm-svn: 320905
2017-12-16 02:10:00 +00:00
Eugene Leviant cb12249238 [ThinLTO] Disallow multiple prevailing defs
https://reviews.llvm.org/D41291

llvm-svn: 320825
2017-12-15 16:27:33 +00:00
Eugene Leviant 746f152dd6 [LLVMgold] Don't set undefined symbol as prevailing
Differential revision: https://reviews.llvm.org/D41113

llvm-svn: 320794
2017-12-15 09:18:21 +00:00
Michael Zolotukhin e893b46b4a Remove redundant includes from lib/LTO.
llvm-svn: 320623
2017-12-13 21:30:53 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
Bob Haarman 847a77ffb3 LTO: clarify why we need to gracefully handle sys::fs::rename failures
Reviewers: pcc, rafael

Reviewed By: pcc

Subscribers: mehdi_amini, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D40094

llvm-svn: 318362
2017-11-16 01:16:52 +00:00
Rafael Espindola a17fca06ee Use TempFile in lto caching.
This requires a small change to TempFile: allowing a discard after a
failed keep.

With this the cache now handles signals and reuses a fd instead of
reopening the file.

llvm-svn: 318322
2017-11-15 19:09:22 +00:00
Bob Haarman a17bd12185 LTO: don't fatal when value for cache key already exists
Summary:
LTO/Caching.cpp uses file rename to atomically set the value for a
cache key. On Windows, this fails when the destination file already
exists. Previously, LLVM would report_fatal_error in such
cases. However, because the old and the new value for the cache key
are supposed to be equivalent, it actually doesn't matter which one we
keep. This change makes it so that failing the rename when an openable
file with the desired name already exists causes us to report success
instead of fataling.

Reviewers: pcc, hans

Subscribers: mehdi_amini, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D39874

llvm-svn: 317899
2017-11-10 17:08:21 +00:00
Sean Fertile 4595a915f6 [LTO][ThinLTO] Use the linker resolutions to mark global values as dso_local.
Now that we have a way to mark GlobalValues as local we can use the symbol
resolutions that the linker plugin provides as part of lto/thinlto link
step to refine the compilers view on what symbols will end up being local.

Originally commited as r317374, but reverted in r317395 to update some missed
tests.

Differential Revision: https://reviews.llvm.org/D35702

llvm-svn: 317408
2017-11-04 17:04:39 +00:00
Sean Fertile 39770ca0a1 Revert "[LTO][ThinLTO] Use the linker resolutions to mark global values ..."
Changes more tests then expected on one of the build bots.
reverting to investigate.

This reverts https://llvm.org/svn/llvm-project/llvm/trunk@317374

llvm-svn: 317395
2017-11-04 01:54:20 +00:00
Sean Fertile 36528c2a9b [LTO][ThinLTO] Use the linker resolutions to mark global values as dso_local.
Now that we have a way to mark GlobalValues as local we can use the symbol
resolutions that the linker plugin provides as part of lto/thinlto link
step to refine the compilers view on what symbols will end up being local.

Differential Revision: https://reviews.llvm.org/D35702

llvm-svn: 317374
2017-11-03 21:45:55 +00:00
Aaron Ballman ecf0e95267 Add llvm::for_each as a range-based extensions to <algorithm> and make use of it in some cases where it is a more clear alternative to std::for_each.
llvm-svn: 317356
2017-11-03 20:01:25 +00:00
Peter Collingbourne 9fb6e1a037 LTO: Apply global DCE to ThinLTO modules at LTO opt level 0.
This is necessary because DCE is applied to full LTO modules. Without
this change, a reference from a dead ThinLTO global to a dead full
LTO global will result in an undefined reference at link time.

This problem is only observable when --gc-sections is disabled, or
when targeting COFF, as the COFF port of lld requires all symbols to
have a definition even if all references are dead (this is consistent
with link.exe).

This change also adds an EliminateAvailableExternally pass at -O0. This
is necessary to handle the situation on Windows where a non-prevailing
copy of a linkonce_odr function has an SEH filter function; any
such filters must be DCE'd because they will contain a call to the
llvm.localrecover intrinsic, passing as an argument the address of the
function that the filter belongs to, and llvm.localrecover requires
this function to be defined locally.

Fixes PR35142.

Differential Revision: https://reviews.llvm.org/D39484

llvm-svn: 317108
2017-11-01 17:58:39 +00:00
Nico Weber 05c988473f LTOModule::isBitcodeFile() shouldn't assert when returning false.
Fixes a bunch of assert-on-invalid-bitcode regressions after 315483.
Expected<> calls assertIsChecked() in its dtor, and operator bool() only calls
setChecked() if there's no error. So for functions that don't return an error
itself, the Expected<> version needs explicit code to disarm the error that the
ErrorOr<> code didn't need.

https://reviews.llvm.org/D39437

llvm-svn: 317010
2017-10-31 16:39:47 +00:00
Sanjay Patel b049173157 [SimplifyCFG] use pass options and remove the latesimplifycfg pass
This is no-functional-change-intended.

This is repackaging the functionality of D30333 (defer switch-to-lookup-tables) and 
D35411 (defer folding unconditional branches) with pass parameters rather than a named
"latesimplifycfg" pass. Now that we have individual options to control the functionality,
we could decouple when these fire (but that's an independent patch if desired). 

The next planned step would be to add another option bit to disable the sinking transform
mentioned in D38566. This should also make it clear that the new pass manager needs to
be updated to limit simplifycfg in the same way as the old pass manager.

Differential Revision: https://reviews.llvm.org/D38631

llvm-svn: 316835
2017-10-28 18:43:07 +00:00
Bob Haarman 9ce2d03e54 [raw_fd_ostream] report actual error in error messages
Summary:
Previously, we would emit error messages like "IO failure on output
stream". This change causes use to include information about what
actually went wrong, e.g. "No space left on device".

Reviewers: sunfish, rnk

Reviewed By: rnk

Subscribers: mehdi_amini, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D39203

llvm-svn: 316404
2017-10-24 01:26:22 +00:00
Rafael Espindola 3500f5e3bf Convert the last uses of ErrorOr in include/llvm/Object.
llvm-svn: 315483
2017-10-11 18:07:18 +00:00
Peter Collingbourne d5fc37cc88 LTO: Improve error reporting when adding a cache entry.
Move error handling code next to the code that returns the error,
and change the error message in order to distinguish it from a similar
error message elsewhere in this file.

llvm-svn: 314745
2017-10-03 00:44:21 +00:00
Adrian Prantl a8b2ddbde4 Move the stripping of invalid debug info from the Verifier to AutoUpgrade.
This came out of a recent discussion on llvm-dev
(https://reviews.llvm.org/D38042). Currently the Verifier will strip
the debug info metadata from a module if it finds the dbeug info to be
malformed. This feature is very valuable since it allows us to improve
the Verifier by making it stricter without breaking bcompatibility,
but arguable the Verifier pass should not be modifying the IR. This
patch moves the stripping of broken debug info into AutoUpgrade
(UpgradeDebugInfo to be precise), which is a much better location for
this since the stripping of malformed (i.e., produced by older, buggy
versions of Clang) is a (harsh) form of AutoUpgrade.

This change is mostly NFC in nature, the one big difference is the
behavior when LLVM module passes are introducing malformed debug
info. Prior to this patch, a NoAsserts build would have printed a
warning and stripped the debug info, after this patch the Verifier
will report a fatal error. I believe this behavior is actually more
desirable anyway.

Differential Revision: https://reviews.llvm.org/D38184

llvm-svn: 314699
2017-10-02 18:31:29 +00:00
Reid Kleckner 3fc649cb76 [Support] Rename tool_output_file to ToolOutputFile, NFC
This class isn't similar to anything from the STL, so it shouldn't use
the STL naming conventions.

llvm-svn: 314050
2017-09-23 01:03:17 +00:00
Johan Engelen dcebe4fc14 Revert "[ThinLTO] Avoid archive member collisions with old API"
This reverts commit r313488, because it breaks compilation on Android and breaks llvm-lto. 

llvm-svn: 313489
2017-09-17 18:11:26 +00:00
Johan Engelen d3a827126f [ThinLTO] Avoid archive member collisions with old API
Summary:
ld64 on OSX uses the old ThinLTOCodegenerator API. When two modules have the same name in an archive (valid archive), a name collision happens for the modules' buffer identifiers.
This PR resolves this, by suffixing the module name with an increasing number such that the identifiers are guaranteed to be unique.

For a similar fix in LLD, see https://reviews.llvm.org/D25495

Reviewers: mehdi_amini, tejohnson

Reviewed By: mehdi_amini

Subscribers: inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D37961

llvm-svn: 313488
2017-09-17 17:38:26 +00:00
Vivek Pandya b5ab895e2a This patch fixes https://bugs.llvm.org/show_bug.cgi?id=32352
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled. 
However LLVM-C API users can still provide callback function for diagnostic handler.

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

llvm-svn: 313382
2017-09-15 19:30:59 +00:00
Peter Collingbourne b9b6025328 LowerTypeTests: Add import/export support for targets without absolute symbol constants.
The rationale is the same as for r312967.

Differential Revision: https://reviews.llvm.org/D37408

llvm-svn: 312968
2017-09-11 22:49:10 +00:00
Peter Collingbourne b15a35e604 WholeProgramDevirt: Add import/export support for targets without absolute symbol constants.
Not all targets support the use of absolute symbols to export
constants. In particular, ARM has a wide variety of constant encodings
that cannot currently be relocated by linkers. So instead of exporting
the constants using symbols, export them directly in the summary.
The values of the constants are left as zeroes on targets that support
symbolic exports.

This may result in more cache misses when targeting those architectures
as a result of arbitrary changes in constant values, but this seems
somewhat unavoidable for now.

Differential Revision: https://reviews.llvm.org/D37407

llvm-svn: 312967
2017-09-11 22:34:42 +00:00
Peter Collingbourne 264d7c9021 LTO: Remove unnecessary Windows support code.
I empirically verified that open files can in fact be renamed on
Windows with sys::fs::rename, so remove the incorrect code and comment.

llvm-svn: 312683
2017-09-07 00:55:00 +00:00
Peter Collingbourne d0e9c167d8 LTO: Try to open cache files before renaming them.
It appears that a potential race between the cache client and the cache
pruner that I thought was unlikely actually happened in practice [1].
Try to avoid the race condition by opening the temporary file before
renaming it. Do this only on non-Windows platforms because we cannot
rename open files on Windows using the sys::fs::rename function.

[1] https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.memory%2FLinux_CFI%2F1610%2F%2B%2Frecipes%2Fsteps%2Fcompile%2F0%2Fstdout

Differential Revision: https://reviews.llvm.org/D37410

llvm-svn: 312567
2017-09-05 19:51:38 +00:00
Evgeniy Stepanov 3427d17cf8 Fix thinlto cache key computation for cfi-icall.
Summary:
Fixed PR33966.

CFI code generation for users (not just callers) of a function depends
on whether this function has a jumptable entry or not. This
information needs to be encoded in of thinlto cache key.

We filter the jumptable list against functions that are actually
referenced in the current module.

Subscribers: mehdi_amini, inglorion, eraman, hiraditya

Differential Revision: https://reviews.llvm.org/D36346

llvm-svn: 310536
2017-08-09 23:24:07 +00:00
Rafael Espindola 79e238afee Delete Default and JITDefault code models
IMHO it is an antipattern to have a enum value that is Default.

At any given piece of code it is not clear if we have to handle
Default or if has already been mapped to a concrete value. In this
case in particular, only the target can do the mapping and it is nice
to make sure it is always done.

This deletes the two default enum values of CodeModel and uses an
explicit Optional<CodeModel> when it is possible that it is
unspecified.

llvm-svn: 309911
2017-08-03 02:16:21 +00:00
Dehao Chen 3246dc3df1 Fix the bug that parseAAPipeline is not invoked in runNewPMPasses in release compiler.
Summary: The logic is guarded by "assert".

Reviewers: davidxl, davide, chandlerc

Reviewed By: davide, chandlerc

Subscribers: sanjoy, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D36195

llvm-svn: 309787
2017-08-02 03:03:19 +00:00
Dehao Chen 89d3226019 Update the new PM pipeline to make ICP aware if it is SamplePGO build.
Summary: In ThinLTO backend compile, OPTOptions are not set so that the ICP in ThinLTO backend does not know if it is a SamplePGO build, in which profile count needs to be annotated directly on call instructions. This patch cleaned up the PGOOptions handling logic and passes down PGOOptions to ThinLTO backend.

Reviewers: chandlerc, tejohnson, davidxl

Reviewed By: chandlerc

Subscribers: sanjoy, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D36052

llvm-svn: 309780
2017-08-02 01:28:31 +00:00
Peter Collingbourne e776dd9ca2 LTO: Export functions referenced by the CFI jump table.
If the LowerTypeTests pass decides to add a function to a jump
table for CFI, it will add its name to the set cfiFunctionDefs,
which among other things will cause the function to be renamed in
the ThinLTO backend.

One other thing that we must do with such functions is to not
internalize them, because the jump table in the full LTO object will
contain a reference to the actual function body in the ThinLTO object.

This patch handles that by ensuring that we export any functions
whose names appear in the cfiFunctionDefs set.

Fixes PR33831.

Differential Revision: https://reviews.llvm.org/D35605

llvm-svn: 308504
2017-07-19 18:18:19 +00:00
Dehao Chen 5d96ee4fab Use DenseMap instead std::map for GVSummaryMapTy.
Summary: This speeds-up thin-link by ~47% for large programs.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: sanjoy, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D35148

llvm-svn: 307578
2017-07-10 20:12:54 +00:00