Commit Graph

482 Commits

Author SHA1 Message Date
Akira Hatanaka b10bff1183 [ThinLTO] Do not assert when adding a module with a different but
compatible target triple

Currently, an assertion fails in ThinLTOCodeGenerator::addModule when
the target triple of the module being added doesn't match that of the
one stored in TMBuilder. This patch relaxes the constraint and makes
changes to allow target triples that only differ in their version
numbers on Apple platforms, similarly to what r228999 did.

rdar://problem/30133904

Differential Revision: https://reviews.llvm.org/D33291

llvm-svn: 303326
2017-05-18 03:52:29 +00:00
James Henderson 852f6fde01 [LTO] Print time-passes information at conclusion of LTO codegen
The information collected when requested by -time-passes is only printed when
llvm_shutdown is called at the moment. This means that when linking against the LTO
library dynamically and using the C interface, it is not possible to see the timing
information, because llvm_shutdown cannot be called. This change modifies the LTO
code generation functions for both regular LTO and thin LTO to explicitly print and
reset the timing information.

I have tested that this works with our proprietary linker. However, as this relies
on a specific method of building and linking against the LTO library, I'm not sure
how or if this can be tested in the LLVM testsuite.

Reviewed by: mehdi_amini

Differential Revision: https://reviews.llvm.org/D32803

llvm-svn: 303152
2017-05-16 09:43:21 +00:00
Peter Collingbourne 6f0ecca3b5 IR: Give function GlobalValue::getRealLinkageName() a less misleading name: dropLLVMManglingEscape().
This function gives the wrong answer on some non-ELF platforms in some
cases. The function that does the right thing lives in Mangler.h. To try to
discourage people from using this function, give it a different name.

Differential Revision: https://reviews.llvm.org/D33162

llvm-svn: 303134
2017-05-16 00:39:01 +00:00
Adrian Prantl 1fa362f811 LTO: Don't verify modules twice in verifyMergedModuleOnce
Differential Revision: https://reviews.llvm.org/D33140

llvm-svn: 302951
2017-05-12 21:38:32 +00:00
Teresa Johnson 94624aca2a Ensure non-null ProfileSummaryInfo passed to ModuleSummaryIndex builder
This fixes a ubsan bot failure after r302597, which made getProfileCount
non-static, but ended up invoking it on a null ProfileSummaryInfo object
in some cases from buildModuleSummaryIndex.

Most testing passed because the non-static getProfileCount currently
doesn't access any member variables, but I found this when testing a
follow on patch (D32877) that adds a member variable access.

llvm-svn: 302705
2017-05-10 18:52:16 +00:00
Peter Collingbourne 9667b91b13 Re-apply r302108, "IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI."
with a fix for the clang backend.

llvm-svn: 302176
2017-05-04 18:03:25 +00:00
Eric Liu f6039f255e Revert "IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI."
This reverts commit r302108. This causes crash in clang bootstrap with LTO.

Contacted the auther in the original commit.

llvm-svn: 302140
2017-05-04 11:49:39 +00:00
Peter Collingbourne 5f85a9deda IR: Use pointers instead of GUIDs to represent edges in the module summary. NFCI.
When profiling a no-op incremental link of Chromium I found that the functions
computeImportForFunction and computeDeadSymbols were consuming roughly 10% of
the profile. The goal of this change is to improve the performance of those
functions by changing the map lookups that they were previously doing into
pointer dereferences.

This is achieved by changing the ValueInfo data structure to be a pointer to
an element of the global value map owned by ModuleSummaryIndex, and changing
reference lists in the GlobalValueSummary to hold ValueInfos instead of GUIDs.
This means that a ValueInfo will take a client directly to the summary list
for a given GUID.

Differential Revision: https://reviews.llvm.org/D32471

llvm-svn: 302108
2017-05-04 03:36:16 +00:00
Peter Collingbourne 74d22dd7dc Bitcode: Make the summary reader responsible for merging. NFCI.
This is to prepare for an upcoming change which uses pointers instead of
GUIDs to represent references.

Differential Revision: https://reviews.llvm.org/D32469

llvm-svn: 301843
2017-05-01 22:04:36 +00:00
Peter Collingbourne c15d60b772 Object: Remove ModuleSummaryIndexObjectFile class.
Differential Revision: https://reviews.llvm.org/D32195

llvm-svn: 301832
2017-05-01 20:42:32 +00:00
Peter Collingbourne fa58f7528e LTO: Mark undefined module asm symbols as used.
Marking them as used causes them to be considered visible outside of LTO. This
prevents the symbols from being internalized or discarded, either by GlobalDCE
or by summary-based dead stripping in ThinLTO.

This change makes it unnecessary to add these symbols to llvm.compiler.used
in the backend, as the symbols are kept alive by virtue of being external,
so remove the backend code that handles that.

Fixes PR32798.

Differential Revision: https://reviews.llvm.org/D32544

llvm-svn: 301438
2017-04-26 17:53:39 +00:00
Peter Collingbourne 8446f1fe6a Object, LTO: Add target triple to irsymtab and LTO API.
Start using it in LLD to avoid needing to read bitcode again just to get the
target triple, and in llvm-lto2 to avoid printing symbol table information
that is inappropriate for the target.

Differential Revision: https://reviews.llvm.org/D32038

llvm-svn: 300300
2017-04-14 02:55:06 +00:00
Peter Collingbourne 942fa56f40 Support: Add a VCSRevision.h header file.
This is a magic header file supported by the build system that provides a
single definition, LLVM_REVISION, containing an LLVM revision identifier,
if available. This functionality previously lived in the LTO library, but
I am moving it out to lib/Support because I want to also start using it in
lib/Object to create the IR symbol table.

This change also fixes a bug where LLVM_REVISION was never actually being
used in lib/LTO because the macro HAS_LLVM_REVISION was never defined (it
was misspelled as HAVE_SVN_VERSION_INC in lib/LTO/CMakeLists.txt, and was
only being defined in a non-existent file Version.cpp).

I also changed the code to use "git rev-parse --git-dir" to locate the .git
directory, instead of looking for it in the LLVM source root directory,
which makes this compatible with monorepos as well as git worktrees.

Differential Revision: https://reviews.llvm.org/D31985

llvm-svn: 300160
2017-04-13 01:26:12 +00:00
Bob Haarman d6aea71957 LTO: call getRealLinkageName on IRNames before feeding to getGUID
Summary: GlobalValue has two getGUID methods: an instance method and a static method. The static method takes a string, which is expected to be what GlobalValue::getRealLinkageName() would return. In LTO.cpp, we were not doing this consistently, sometimes passing an IR name instead. This change makes it so that we call getRealLinkageName() first, making the static getGUID return value consistent with the instance method. Without this change, compiling FileCheck with ThinLTO on Windows fails with numerous undefined symbol errors. With the change, it builds successfully.

Reviewers: pcc, rnk

Reviewed By: pcc

Subscribers: tejohnson, mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D31444

llvm-svn: 299268
2017-03-31 21:56:30 +00:00
Peter Collingbourne 7b30f16c9f Re-apply r299168 and r299169 now that the libdeps are fixed.
llvm-svn: 299184
2017-03-31 04:47:07 +00:00
Peter Collingbourne c66018e247 Move llvm::emitLinkerFlagsForGlobalCOFF() to Mangler.
llvm-svn: 299183
2017-03-31 04:46:50 +00:00
Peter Collingbourne 2e0ffe9858 Move llvm::canBeOmittedFromSymbolTable() to Analysis.
llvm-svn: 299182
2017-03-31 04:46:31 +00:00
Peter Collingbourne f10698b940 Revert r299168 and r299169 due to library dependency issues.
http://bb.pgr.jp/builders/i686-mingw32-RA-on-linux/builds/25073/steps/build_llvmclang/logs/stdio

llvm-svn: 299171
2017-03-31 02:44:50 +00:00
Peter Collingbourne d9717aa0e4 LTO: Reduce memory consumption by creating an in-memory symbol table for InputFiles. NFCI.
Introduce symbol table data structures that can be potentially written to
disk, have the LTO library build those data structures using temporarily
constructed modules and redirect the LTO library implementation to go through
those data structures. This allows us to remove the LLVMContext and Modules
owned by InputFile.

With this change I measured a peak memory consumption decrease from 5.4GB to
2.8GB in a no-op incremental ThinLTO link of Chromium on Linux. The impact on
memory consumption is larger in COFF linkers where we are currently forced
to materialize all metadata in order to read linker options. Peak memory
consumption linking a large piece of Chromium for Windows with full LTO and
debug info decreases from >64GB (OOM) to 15GB.

Part of PR27551.

Differential Revision: https://reviews.llvm.org/D31364

llvm-svn: 299168
2017-03-31 02:28:30 +00:00
Peter Collingbourne 192d8520de More accurate header inclusions. NFC.
llvm-svn: 298960
2017-03-28 23:35:34 +00:00
Peter Collingbourne 0d56b959ad LTO: Replace InputFile::Symbol::getFlags() with predicate accessors. NFC.
This makes the predicates independent of the flag representation
and makes the code a little easier to read.

llvm-svn: 298951
2017-03-28 22:31:35 +00:00
Mehdi Amini b5a46c1f45 Add support for -fno-builtin to LTO and ThinLTO to libLTO
Reviewers: tejohnson, pcc

Subscribers: Prazek, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D30791

llvm-svn: 298936
2017-03-28 18:55:44 +00:00
Joerg Sonnenberger fa7367428a Split the SimplifyCFG pass into two variants.
The first variant contains all current transformations except
transforming switches into lookup tables. The second variant
contains all current transformations.

The switch-to-lookup-table conversion results in code that is more
difficult to analyze and optimize by other passes. Most importantly,
it can inhibit Dead Code Elimination. As such it is often beneficial to
only apply this transformation very late. A common example is inlining,
which can often result in range restrictions for the switch expression.

Changes in execution time according to LNT:
SingleSource/Benchmarks/Misc/fp-convert +3.03%
MultiSource/Benchmarks/ASC_Sequoia/CrystalMk/CrystalMk -11.20%
MultiSource/Benchmarks/Olden/perimeter/perimeter -10.43%
and a couple of smaller changes. For perimeter it also results 2.6%
a smaller binary.

Differential Revision: https://reviews.llvm.org/D30333

llvm-svn: 298799
2017-03-26 06:44:08 +00:00
Peter Collingbourne f7691d8b41 IPO: Const correctness for summaries passed into passes.
Pass const qualified summaries into importers and unqualified summaries into
exporters. This lets us const-qualify the summary argument to thinBackend.

Differential Revision: https://reviews.llvm.org/D31230

llvm-svn: 298534
2017-03-22 18:22:59 +00:00
Peter Collingbourne d786047583 Try using llvm::errc, should hopefully fix version mismatch problem on clang-s390x-linux bot.
llvm-svn: 298285
2017-03-20 18:19:41 +00:00
Peter Collingbourne 25a17ba4c7 Support, LTO: When pruning a directory, ignore files matching a prefix.
This is a safeguard against data loss if the user specifies a directory
that is not a cache directory. Teach the existing cache pruning clients
to create files with appropriate names.

Differential Revision: https://reviews.llvm.org/D31109

llvm-svn: 298271
2017-03-20 16:41:57 +00:00
Peter Collingbourne 6bfe4d369b LTO: Work around libstdc++ version mismatch bug, see D31063 review thread.
llvm-svn: 298127
2017-03-17 21:49:09 +00:00
Peter Collingbourne 128423f99b LTO: Fix a potential race condition in the caching API.
After the call to sys::fs::exists succeeds, indicating a cache hit, we call
AddFile and the client will open the file using the supplied path. If the
client is using cache pruning, there is a potential race between the pruner
and the client. To avoid this, change the caching API so that it provides
a MemoryBuffer to the client, and have clients use that MemoryBuffer where
possible.

This scheme won't work with the gold plugin because the plugin API expects a
file path. So we have the gold plugin use the buffer identifier as a path and
live with the race for now. (Note that the gold plugin isn't actually affected
by the problem at the moment because it doesn't support cache pruning.)

This effectively reverts r279883 modulo the change to use the existing path
in the gold plugin.

Differential Revision: https://reviews.llvm.org/D31063

llvm-svn: 298020
2017-03-17 00:34:07 +00:00
Peter Collingbourne cb46a6baf7 LTO: Create temporary cache files in the cache directory instead of $TMPDIR.
This fixes a race condition where another linker process can observe a
partially written file if we copy it from another file system, and allows
the link to be independent of the amount of free disk space in $TMPDIR.

Differential Revision: https://reviews.llvm.org/D31045

llvm-svn: 297970
2017-03-16 18:20:06 +00:00
Peter Collingbourne cead56fb22 Support: Simplify the CachePruning API. NFCI.
Change the function that implements the pruning into a free function that
takes the policy as a struct argument.

Differential Revision: https://reviews.llvm.org/D31009

llvm-svn: 297907
2017-03-15 22:54:18 +00:00
Peter Collingbourne 711284b017 LTO: Hash type identifier resolutions for WholeProgramDevirt.
Differential Revision: https://reviews.llvm.org/D30555

llvm-svn: 297514
2017-03-10 21:37:10 +00:00
Peter Collingbourne 780a4dd35f LTO: Hash type identifier resolutions for LowerTypeTests.
Differential Revision: https://reviews.llvm.org/D30553

llvm-svn: 297513
2017-03-10 21:35:17 +00:00
Teresa Johnson d820447212 Perform symbol binding for .symver versioned symbols
Summary:
In a .symver assembler directive like:
.symver name, name2@@nodename
"name2@@nodename" should get the same symbol binding as "name".

While the ELF object writer is updating the symbol binding for .symver
aliases before emitting the object file, not doing so when the module
inline assembly is handled by the RecordStreamer is causing the wrong
behavior in *LTO mode.

E.g. when "name" is global, "name2@@nodename" must also be marked as
global. Otherwise, the symbol is skipped when iterating over the LTO
InputFile symbols (InputFile::Symbol::shouldSkip). So, for example,
when performing any *LTO via the gold-plugin, the versioned symbol
definition is not recorded by the plugin and passed back to the
linker. If the object was in an archive, and there were no other symbols
needed from that object, the object would not be included in the final
link and references to the versioned symbol are undefined.

The llvm-lto2 tests added will give an error about an unused symbol
resolution without the fix.

Reviewers: rafael, pcc

Reviewed By: pcc

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D30485

llvm-svn: 297332
2017-03-09 00:19:49 +00:00
Peter Collingbourne 54a52b7569 LTO: Hash the set of imported symbols for each module.
This set may affect code generation and is sensitive to link order (and
possibly in the future to the linker's choice of prevailing symbol), so we
need to include it.

Differential Revision: https://reviews.llvm.org/D30586

llvm-svn: 296907
2017-03-03 20:25:30 +00:00
Peter Collingbourne ab76a19afb LTO: When creating a local cache, create the cache directory if it does not already exist.
Differential Revision: https://reviews.llvm.org/D30519

llvm-svn: 296726
2017-03-02 02:02:38 +00:00
Tobias Edler von Koch f454b9eadf [LTO] Add ability to emit assembly to new LTO API
Summary:
Add a field to LTO::Config, CGFileType, to select the file type to emit (object
or assembly). This is useful for testing and to implement -save-temps.

Reviewers: tejohnson, mehdi_amini, pcc

Reviewed By: mehdi_amini

Subscribers: davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D29475

llvm-svn: 295226
2017-02-15 20:36:36 +00:00
Mehdi Amini a0ddb1ed46 [ThinLTO] Make a copy of buffer identifier in ThinLTOCodeGenerator
We can't assume that the `const char *` provided through libLTO has a
lifetime that expands beyond the codegenerator itself.

llvm-svn: 295018
2017-02-14 02:20:51 +00:00
Davide Italiano 20a895c4be [LTO] Make sure we flush buffers to work around linker shenanigans.
lld, at least, doesn't call global destructors by default (unless
--full-shutdown is passed) because it's, allegedly, expensive.

llvm-svn: 294953
2017-02-13 14:39:51 +00:00
Davide Italiano ebd471974a [lib/LTO] Initial support for optimization remarks in the new API.
llvm-svn: 294882
2017-02-12 03:31:30 +00:00
Davide Italiano 690ed9dec7 [LTO] Share the optimization remarks setup between Thin/Full LTO.
llvm-svn: 294807
2017-02-10 23:49:38 +00:00
Davide Italiano 46d72b1b7f [lib/LTO] Rework optimization remarkers setup.
This makes this code much more similar to what ThinLTO is
using (also API wise), so now we can probably use a single
code path instead of copying stuff around.

llvm-svn: 294792
2017-02-10 22:16:17 +00:00
Bob Haarman e2fe59fddd fix nullptr Mangler in LTOModule
Reviewers: kcc, pcc

Subscribers: mehdi_amini

Differential Revision: https://reviews.llvm.org/D29523

llvm-svn: 294079
2017-02-04 01:28:44 +00:00
Peter Collingbourne e6fd9ff96a IRMover: Merge flags LinkModuleInlineAsm and IsPerformingImport.
Currently these flags are always the inverse of each other, so there is
no need to keep them separate.

Differential Revision: https://reviews.llvm.org/D29471

llvm-svn: 294016
2017-02-03 17:01:14 +00:00
Mehdi Amini 1380edf4ef Revert "[ThinLTO] Add an auto-hide feature"
This reverts commit r293970.

After more discussion, this belongs to the linker side and
there is no added value to do it at this level.

llvm-svn: 293993
2017-02-03 07:41:43 +00:00
Mehdi Amini b0a8ff71e5 [ThinLTO] Add an auto-hide feature
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.

This is a recommit of r293912 after fixing build failures,
and a recommit of r293918 after fixing LLD tests.

Differential Revision: https://reviews.llvm.org/D28978

llvm-svn: 293970
2017-02-03 00:32:38 +00:00
Mehdi Amini 21c89dc920 Revert "[ThinLTO] Add an auto-hide feature"
This reverts commit r293918, one lld test does not pass.

llvm-svn: 293961
2017-02-02 23:20:36 +00:00
Bob Haarman dd4ebc1d3b [lto] add getLinkerOpts()
Summary: Some compilers, including MSVC and Clang, allow linker options to be specified in source files. In the legacy LTO API, there is a getLinkerOpts() method that returns linker options for the bitcode module being processed. This change adds that method to the new API, so that the COFF linker can get the right linker options when using the new LTO API.

Reviewers: pcc, ruiu, mehdi_amini, tejohnson

Reviewed By: pcc

Differential Revision: https://reviews.llvm.org/D29207

llvm-svn: 293950
2017-02-02 23:00:49 +00:00
Mehdi Amini 97624fb1ec [ThinLTO] Add an auto-hide feature
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.

This is a recommit of r293912 after fixing build failures.

Differential Revision: https://reviews.llvm.org/D28978

llvm-svn: 293918
2017-02-02 18:31:35 +00:00
Mehdi Amini 827600deaf Revert "[ThinLTO] Add an auto-hide feature"
This reverts r293912, bots are broken.

llvm-svn: 293914
2017-02-02 18:24:37 +00:00
Mehdi Amini dc5a7444f0 [ThinLTO] Add an auto-hide feature
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.

Differential Revision: https://reviews.llvm.org/D28978

llvm-svn: 293912
2017-02-02 18:13:46 +00:00