Commit Graph

394 Commits

Author SHA1 Message Date
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
Saleem Abdulrasool 98541b09f4 Revert "gold: add a cast to appease std::max NFC"
This was fixed differently by Teresa and this should no longer be needed.

llvm-svn: 278622
2016-08-14 05:07:20 +00:00
Saleem Abdulrasool 0bc85613f7 gold: add a cast to appease std::max NFC
llvm-svn: 278567
2016-08-12 21:56:12 +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
Teresa Johnson 1e2708c9e0 [ThinLTO/gold] Support for getting list of included objects from gold
Summary:
In the distributed backend case, the ThinLink step and the final native
object link are separate processes. This can be problematic when archive
libraries are involved in the link (e.g. via --start-lib/--end-lib
pairs). The linker only includes objects from libraries when
there is a strong reference to them, and depending on the intervening
ThinLTO backend processes' importing/inlining, the strong references
may appear different in the two link steps. See D22356 and D22467
for two scenarios where this causes issues.

To ensure that the final link includes the same objects, this patch
adds support for an "=filename" form of the thinlto-index-only plugin
option, in which case objects gold included in the link are emitted to
the given filename. This should be used as input to the final link (e.g.
via the @filename option to gold), instead of listing all the objects
within --start-lib/--end-lib pairs again.

Note that the support for the gold callback that identifies included
objects was added in gold version 1.12.

Reviewers: davidxl, mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D22677

llvm-svn: 276450
2016-07-22 18:20:22 +00:00
Teresa Johnson 35e0204eec [ThinLTO/gold] Perform index-based weak/linkonce resolution
Summary:
Invoke the weak/linkonce symbol resolution support (already used by
libLTO) that operates via the summary index.

This ensures prevailing linkonce are kept, by making them weak, and
marks preempted copies as available_externally when possible.

With this change, the older support for keeping the prevailing linkonce
(by changing their symbol resolution) is removed.

Reviewers: mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: http://reviews.llvm.org/D22302

llvm-svn: 275474
2016-07-14 21:13:24 +00:00
Teresa Johnson b907d06151 [ThinLTO/gold] Enable symbol resolution in distributed backend case
While testing a follow-on change to enable index-based symbol resolution
and internalization in the distributed backends, I realized that a test
case change I made in r275247 was only required because we were not
analyzing symbols in the claimed files in thinlto-index-only mode.

In the fixed test case there should be no internalization because we are
linking in -shared mode, so f() is in fact exported, which is detected
properly when we analyze symbols in thinlto-index-only mode. Note that
this is not (yet) a correctness issue (because we are not yet performing
the index-based linkage optimizations in the distributed backends -
that's coming in a follow-on patch).

llvm-svn: 275277
2016-07-13 16:35:56 +00:00
Teresa Johnson 27694571b1 [ThinLTO/gold] ThinLTO internalization fixes
Internalization was missing cases where we originally had a local symbol
that was promoted eagerly but not actually exported. This is because we
were only internalizing the set of global (non-local) symbols that were
PREVAILAING_DEF_IRONLY. Instead, collect the set of global symbols that
are referenced outside of a single IR file, and skip internalization for
those.

llvm-svn: 275247
2016-07-13 03:42:41 +00:00
Rafael Espindola aee1a0e407 Don't use the new x86 relax relocations on the gold plugin.
Should bring back the bots with old versions.

llvm-svn: 273022
2016-06-17 17:53:57 +00:00
Peter Collingbourne 96efdd6107 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

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

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

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

Part of the fix for PR27553.

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

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Teresa Johnson 7ab1f69272 [ThinLTO/gold] Enable summary-based internalization
Summary: Enable existing summary-based importing support in the gold-plugin.

Reviewers: mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: http://reviews.llvm.org/D21080

llvm-svn: 272239
2016-06-09 01:14:13 +00:00
Teresa Johnson 4cafbdd4bd [ThinLTO/gold] Pass import lists by reference (NFC)
In my earlier patch r271690 I missed passing a map by reference in one
place.

llvm-svn: 271732
2016-06-03 20:46:32 +00:00
Teresa Johnson 56c68353fa [ThinLTO/gold] Pass down the imports lists from the thin link (NFC)
No longer need to compute the imports in each backend thread.

llvm-svn: 271690
2016-06-03 17:15:54 +00:00
Benjamin Kramer 82de7d323d Apply clang-tidy's misc-move-constructor-init throughout LLVM.
No functionality change intended, maybe a tiny performance improvement.

llvm-svn: 270997
2016-05-27 14:27:24 +00:00
Peter Collingbourne 1eaa97f439 Linker: teach the IR mover to return llvm::Error.
This will be needed in order to consistently return an Error
to clients of the API being developed in D20268.

Differential Revision: http://reviews.llvm.org/D20550

llvm-svn: 270967
2016-05-27 05:21:35 +00:00
Teresa Johnson 683abe79b2 [ThinLTO/gold] Handle bitcode archives
Summary:
Several changes were required for ThinLTO links involving bitcode
archive static libraries. With this patch clang/llvm bootstraps with
ThinLTO and gold.

The first is that the gold callbacks get_input_file and
release_input_file can normally be used to get file information for
each constituent bitcode file within an archive. However, these
interfaces lock the underlying file and can't be for each archive
constituent for ThinLTO backends where we get all the input files up
front and don't release any until after the backend threads complete.
However, it is sufficient to only get and release once per file, and
then each consituent bitcode file can be accessed via get_view. This
required saving some information to identify which file handle is the
"leader" for each claimed file sharing the same file descriptor, and
other information so that get_input_file isn't necessary later when
processing the backends.

Second, the module paths in the index need to distinguish between
different constituent bitcode files within the same archive file,
otherwise they will all end up with the same archive file path.
Do this by appending the offset within the archive for the start of the
bitcode file, returned by get_input_file when we claim each bitcode file,
and saving that along with the file handle.

Third, rather than have the function importer try to load a file based
on the module path identifier (which now contains a suffix to
distinguish different bitcode files within an archive), use a custom
module loader. This is the same approach taken in libLTO, and I am using
the support refactored into the new LTO.h header in r270509. The module
loader parses the bitcode files out of the memory buffers returned from
gold via the get_view callback and saved in a map. This also means that
we call the function importer directly, rather than add it to the pass
pipeline (which was in the plan to do already for other reasons).

Reviewers: pcc, joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D20559

llvm-svn: 270814
2016-05-26 01:46:41 +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
Reid Kleckner 8e96c3e9dd [ThinLTO] Use semicolon to separate path prefix replacement
Summary:
Colons can appear in Windows paths after drive letters. Both colon and
semicolon are valid characters in filenames, but neither are very
common. Semicolon seems just as good, and makes the test pass on
Windows.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D20332

llvm-svn: 269798
2016-05-17 18:43:22 +00:00
Teresa Johnson bbd10b4579 [ThinLTO] Option to control path of distributed backend files
Summary:
Add support to control where files for a distributed backend (the
individual index files and optional imports files) are created.

This is invoked with a new thinlto-prefix-replace option in the gold
plugin and llvm-lto. If specified, expects a string of the form
"oldprefix:newprefix", and instead of generating these files in the
same directory path as the corresponding bitcode file, will use a path
formed by replacing the bitcode file's path prefix matching oldprefix
with newprefix.

Also add a new replace_path_prefix helper to Path.h in libSupport.

Depends on D19636.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19644

llvm-svn: 269771
2016-05-17 14:45:30 +00:00
Teresa Johnson 532e33be42 [ThinLTO] Use correct pipeline for ThinLTO in gold-plugin.
This change is the gold side of the change made in D17115 and clang
patch r261045 to add a ThinLTO specific pipeline that moves more of
the optimization to the backends.

llvm-svn: 269386
2016-05-13 01:25:31 +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
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
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
Evgeniy Stepanov d194e51726 [gold] Fix linkInModule and extend common.ll test.
Fix early exit from linkInModule. IRMover::move returns false on
success and true on error.

Add a few more cases of merged common linkage variables with
different sizes and alignments.

llvm-svn: 267437
2016-04-25 18:23:29 +00:00
Davide Italiano 8d728fccb8 [gold-plugin] Remove dead assignment. NFC.
llvm-svn: 267429
2016-04-25 17:18:45 +00:00
Teresa Johnson 723cd05f83 [gold] Gate value name discarding under save-temps
Summary:
This removes a couple of flags added to control this behavior, and
simply keeps all value names when save-temps is specified.

Reviewers: rafael

Subscribers: llvm-commits, pcc, davide

Differential Revision: http://reviews.llvm.org/D19384

llvm-svn: 267279
2016-04-23 05:15:59 +00:00
Teresa Johnson 143d15bc29 Re-enable "[gold-plugin] Disable name for values other than GlobalValue"
This restores r266871 with a fix for gold tests relying on the value
names, when using a release compiler, by adding a way to disable the
default discarding. Update affected tests to use the new mechanism so
that value names are preserved as expected, regardless of how the
compiler was built.

llvm-svn: 266881
2016-04-20 15:16:57 +00:00
Teresa Johnson b35cc691ea [ThinLTO] Prevent importing of "llvm.used" values
Summary:
This patch prevents importing from (and therefore exporting from) any
module with a "llvm.used" local value. Local values need to be promoted
and renamed when importing, and their presense on the llvm.used variable
indicates that there are opaque uses that won't see the rename. One such
example is a use in inline assembly.

See also the discussion at:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098047.html

As part of this, move collectUsedGlobalVariables out of Transforms/Utils
and into IR/Module so that it can be used more widely. There are several
other places in LLVM that used copies of this code that can be cleaned
up as a follow on NFC patch.

Reviewers: joker.eph

Subscribers: pcc, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18986

llvm-svn: 266877
2016-04-20 14:39:45 +00:00
Teresa Johnson f0bedf5343 Revert "[gold-plugin] Disable name for values other than GlobalValue"
This reverts commit r266871. Setting the default based on the NDEBUG
flag is causing test failures. Need to figure out whether to change this
approach or update tests.

llvm-svn: 266872
2016-04-20 13:18:47 +00:00
Teresa Johnson d3ded4a441 [gold-plugin] Disable name for values other than GlobalValue
Summary:
Applies Mehdi's optimization (r263086) to disable value names other than
for GlobalValues to LTO/ThinLTO performed via the gold-plugin, in the
same manner as it is applied in libLTO.

Reviewers: rafael, joker-eph

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19269

llvm-svn: 266871
2016-04-20 13:01:37 +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 197871d532 Fix a use after move.
llvm-svn: 266566
2016-04-17 18:56:49 +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
Evgeniy Stepanov 268826a287 [gold] Save bitcode for module partitions (save-temps + split codegen).
llvm-svn: 265583
2016-04-06 18:32:13 +00:00
Marianne Mailhot-Sarrasin a5a750eaf1 gold-plugin: Fixed typo in an error message.
llvm-svn: 264860
2016-03-30 12:20:53 +00:00
Davide Italiano 289a43ed0a [gold] Emit a diagnostic in case we fail to remove a file.
llvm-svn: 263914
2016-03-20 20:12:33 +00:00
Davide Italiano 2788a825e7 [gold] Use early return to simplify.
llvm-svn: 263872
2016-03-19 02:34:33 +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
Evgeniy Stepanov 4dc3c8df45 [gold] Fix common symbols handling.
LLVM Gold plugin decides which instance of a common symbol it wants
based on the symbol size in claim_file_hook. If the file that
contains the chosen instance is later dropped from the link, we end
up with an undefined reference.

This change delays this decision until the set of the included files
is known.

llvm-svn: 263180
2016-03-11 00:51:57 +00:00
Mehdi Amini d2d989609f Fix GOLD plugin build after r262976
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 262981
2016-03-09 01:55:15 +00:00
Benjamin Kramer 39988a03a5 [gold] Avoid assertion failures when taking a pointer to an empty vector.
llvm-svn: 262926
2016-03-08 14:02:46 +00:00
Teresa Johnson 3b8f6126ac Fix bot failure from r262721: unintented change in gold-plugin save-temps
The split code gen task ID should not be appended to save-temps output
file when the parallelism factor is 1 (not actually splitting).

llvm-svn: 262731
2016-03-04 18:16:00 +00:00
Teresa Johnson a17f2cd1a3 [ThinLTO] Ensure prevailing linkonce emitted as weak in ThinLTO backends
Summary:
Since IR files are all compiled into separate independent object files
in ThinLTO mode, the prevailing linkonce symbols must be emitted in its
object file even if it is no longer referenced there, e.g. if no
references remain in the module after inlining, since it may be
referenced by another ThinLTO compiled object file. This is done by
changing LDPR_PREVAILING_DEF_IRONLY* symbols to LDPR_PREVAILING_DEF,
which converts the prevailing linkonce to weak. We also don't need the
other prevailing IRONLY handling for internalization, which is not
currently performed for ThinLTO.

Test case included.

Reviewers: davidxl, rafael

Subscribers: rafael, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D16173

llvm-svn: 262727
2016-03-04 17:48:35 +00:00
Teresa Johnson 7cffaf3ad0 [ThinLTO] Launch importing backends in parallel threads from gold plugin
Summary:
Launch ThinLTO backends (LTO and codegen pipelines with importing) in
parallel using a ThreadPool, after creating the combined index.
The number of threads is controlled by the existing -jobs gold plugin
option, or the hardware concurrency if not specified.

The old behavior of exiting after creating the combined index can be
invoked via a new thinlto-index-only plugin option.

This commit involves just the ThinLTO-specific pieces of D15390, the NFC
and other restructuring pieces were committed independently:
  r262677: Add hardware_concurrency interface to llvm::thread (NFC)
  r262719: Change split code gen to use ThreadPool
  r262721: Refactor gold-plugin codegen to prepare for ThinLTO threads (NFC)

Reviewers: pcc, joker.eph, rafael

Subscribers: rafael, davidxl, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D15390

llvm-svn: 262724
2016-03-04 17:06:02 +00:00
Teresa Johnson a9f65554b0 Refactor gold-plugin codegen to prepare for ThinLTO threads (NFC)
This is the NFC part remaining from D15390, which refactors the
current codegen() into a CodeGen class with various modular methods and
other helper functions that will be used by the follow-on ThinLTO piece.

llvm-svn: 262721
2016-03-04 16:36:06 +00:00
Evgeniy Stepanov 330c5a60c7 [gold] Handle modules that are not included in the link.
Gold has a newly added LDPT_GET_SYMBOLS_V3 callback that can
distinguish between a module that is not included in the link, and
one that is included but has its entire interface preempted by others.

Fixes PR26674.

llvm-svn: 262676
2016-03-04 00:23:29 +00:00
Rafael Espindola 40358fb86f Pass a std::unique_ptr to IRMover::move.
It was already the one "destroying" the source module, now the API
reflects that.

llvm-svn: 260989
2016-02-16 18:50:12 +00:00
Chris Bieneman e49730d4ba Remove autoconf support
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html

"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi

Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark

Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D16471

llvm-svn: 258861
2016-01-26 21:29:08 +00:00
Davide Italiano 72d0d89b59 [gold] Remove inconsistent llvm_unreachable().
Differential Revision:	 http://reviews.llvm.org/D16429

llvm-svn: 258561
2016-01-22 21:36:49 +00:00
Rafael Espindola 240529892b Disable use list order on the gold plugin.
It turns out that his is *really* slow. With this change the link of
clang with plugin-opt=emit-llvm goes from 41 to 26 seconds.

We can add an option to enable it again if needed.

llvm-svn: 256302
2015-12-22 23:45:49 +00:00
Teresa Johnson 031bed291e Use LLVM style variable name (NFC)
Fixes variable name from r255779.

llvm-svn: 255824
2015-12-16 21:37:48 +00:00
Teresa Johnson cb15b739ef Add RAII wrapper for gold plugin file management
Suggested in review of r255256.

llvm-svn: 255779
2015-12-16 16:34:06 +00:00
Rafael Espindola 9d2bfc4874 Use diagnostic handler in the LLVMContext
This patch converts code that has access to a LLVMContext to not take a
diagnostic handler.

This has a few advantages

* It is easier to use a consistent diagnostic handler in a single program.
* Less clutter since we are not passing a handler around.

It does make it a bit awkward to implement some C APIs that return a
diagnostic string. I will propose new versions of these APIs and
deprecate the current ones.

llvm-svn: 255571
2015-12-14 23:17:03 +00:00
Teresa Johnson 9d5b71b3d2 [ThinLTO] Release files in gold plugin during combined index (take 2)
Ensure we release the files even when they don't hold a function index
summary section, by restructuring the control flow a little bit.

llvm-svn: 255256
2015-12-10 16:11:23 +00:00
Rafael Espindola caabe22832 Slit lib/Linker in two.
A linker normally has two stages: symbol resolution and "moving stuff".

In lib/Linker there is the complication of lazy linking some globals,
but it was still far more mixed than it needed to.

This splits the linker into a lower level IRMover and the linker proper.
The IRMover just takes a list of globals to move and a callback that
lets the user control what is lazy linked.

The main motivation is that now tools/gold (and soon lld) can use their
own symbol resolution to instruct IRMover what to do.

llvm-svn: 255254
2015-12-10 14:19:35 +00:00
Teresa Johnson db51357c11 [ThinLTO] Release files read when creating combined index in gold plugin
This wasn't causing an issue since at HEAD we exit the linker completely
after creating the combined index.

llvm-svn: 255156
2015-12-09 21:11:42 +00:00
Teresa Johnson af9e93183d Delay context construction to when/if it is needed in gold plugin (NFC)
llvm-svn: 255146
2015-12-09 19:49:40 +00:00
Teresa Johnson b13dbd633a clang-format order of gold-plugin includes (NFC)
llvm-svn: 255144
2015-12-09 19:45:55 +00:00
Rafael Espindola f49a38fc08 Always pass a diagnostic handler to the linker.
Before this patch the diagnostic handler was optional. If it was not
passed, the one in the LLVMContext was used.

That is probably not a pattern we want to follow. If each area has an
optional callback, there is a sea of callbacks and it is hard to follow
which one is called.

Doing this also found cases where the callback is a nice addition, like
testing that no errors or warnings are reported.

The other option is to always use the diagnostic handler in the
LLVMContext. That has a few problems

* To implement the C API we would have to set the diag handler and then
  set it back to the original value.
* Code that creates the context might be far away from code that wants
  the diagnostics.

I do have a patch that implements the second option and will send that as
an RFC.

llvm-svn: 254777
2015-12-04 22:08:53 +00:00
Rafael Espindola 0e309fe860 Use references now that it is natural to do so.
The linker never takes ownership of a module or changes which module it
is refering to, making it natural to use references.

llvm-svn: 254449
2015-12-01 19:50:54 +00:00
Rafael Espindola 19b52383c5 Simplify the linking of recursive data.
Now the ValueMapper has two callbacks. The first one maps the
declaration. The ValueMapper records the mapping and then materializes
the body/initializer.

llvm-svn: 254209
2015-11-27 20:28:19 +00:00
Rafael Espindola bca90bf158 Don't create implicit comdats.
comdats are explicitly represented for some time now.

llvm-svn: 253924
2015-11-23 22:01:51 +00:00
Teresa Johnson 6290dbc0f7 [ThinLTO] Handle bitcode without function summary sections gracefully
Summary:
Several fixes to the handling of bitcode files without function summary
sections so that they are skipped during ThinLTO processing in llvm-lto
and the gold plugin when appropriate instead of aborting.

1 Don't assert when trying to add a FunctionInfo that doesn't have
  a summary attached.
2 Skip FunctionInfo structures that don't have attached function summary
  sections when trying to create the combined function summary.
3 In both llvm-lto and gold-plugin, check whether a bitcode file has
  a function summary section before trying to parse the index, and skip
  the bitcode file if it does not.
4 Fix hasFunctionSummaryInMemBuffer in BitcodeReader, which had a bug
  where we returned to early while looking for the summary section.

Also added llvm-lto and gold-plugin based tests for cases where we
don't have function summaries in the bitcode file. I verified that
either the first couple fixes described above are enough to avoid the
crashes, or fixes 1,3,4. But have combined them all here for added
robustness.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D14903

llvm-svn: 253796
2015-11-21 21:55:48 +00:00
Mehdi Amini 0027c1d21b Remove unused function parameter (NFC)
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 253569
2015-11-19 15:42:34 +00:00
NAKAMURA Takumi b13e63ce08 gold-plugin.cpp: Fix diagnosticHandler corresponding to r253540.
llvm-svn: 253553
2015-11-19 10:43:44 +00:00
Teresa Johnson f72278f051 Clang format a few prior patches (NFC)
I had clang formatted my earlier patches using the wrong style.
Reformatted with the LLVM style.

llvm-svn: 251812
2015-11-02 18:02:11 +00:00
Manuel Klimek 100f40c0fd Make class final to pacify -Wnon-virtual-dtor.
llvm-svn: 250805
2015-10-20 08:21:01 +00:00
Teresa Johnson 3da931f87a Pass FunctionInfoIndex by reference to WriteFunctionSummaryToFile (NFC)
Implemented suggestion by dblakie in review for r250704.

llvm-svn: 250723
2015-10-19 19:06:06 +00:00
Teresa Johnson 8af8d4ed93 Convert gold-plugin unnecessary unique_ptr into local (NFC)
llvm-svn: 250704
2015-10-19 15:23:03 +00:00
Teresa Johnson 403a787e03 Support for function summary index bitcode sections and files.
Summary:
The bitcode format is described in this document:
  https://drive.google.com/file/d/0B036uwnWM6RWdnBLakxmeDdOeXc/view
For more info on ThinLTO see:
  https://sites.google.com/site/llvmthinlto

The first customer is ThinLTO, however the data structures are designed
and named more generally based on prior feedback. There are a few
comments regarding how certain interfaces are used by ThinLTO, and the
options added here to gold currently have ThinLTO-specific names as the
behavior they provoke is currently ThinLTO-specific.

This patch includes support for generating per-module function indexes,
the combined index file via the gold plugin, and several tests
(more are included with the associated clang patch D11908).

Reviewers: dexonsmith, davidxl, joker.eph

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13107

llvm-svn: 249270
2015-10-04 14:33:43 +00:00
Teresa Johnson 8c8fe5a015 Disable the second verification run when performing LTO through
gold in NDEBUG mode.
Follow on patch for r247729 - LTO: Disable extra verify runs in release
builds.

llvm-svn: 247824
2015-09-16 18:06:45 +00:00
Peter Collingbourne 87202a4aac gold-plugin: Implement parallel LTO code generation using llvm::splitCodeGen.
Parallelism can be enabled using a new plugin option, jobs=N, where N is
the number of code generation threads.

Differential Revision: http://reviews.llvm.org/D12308

llvm-svn: 246584
2015-09-01 20:40:22 +00:00
Nick Lewycky 7282dd774f Replace &vector[0] with vector.data() to avoid invalid dereference caught by debug STL. Also move a '*' for consistency and fix an 80-col violation.
llvm-svn: 244134
2015-08-05 21:16:02 +00:00
Chandler Carruth df47bb9a06 Update for r243115 which changed the DataLayout API on TargetMachine but
didn't update the gold-plugin.

llvm-svn: 243121
2015-07-24 17:23:09 +00:00
Rafael Espindola 92200d237a gold-plugin: save the .o when given -save-temps.
The plugin now save the bitcode before and after optimizations and the
.o that is passed to the linker.

llvm-svn: 239726
2015-06-15 13:36:27 +00:00
Duncan P. N. Exon Smith e406c84e30 Fix build error from r234957
llvm-svn: 234958
2015-04-15 00:13:51 +00:00
Duncan P. N. Exon Smith a052ed6381 uselistorder: Pull the bit through WriteToBitcodFile()
Change the callers of `WriteToBitcodeFile()` to pass `true` or
`shouldPreserveBitcodeUseListOrder()` explicitly.  I left the callers
that want to send `false` alone.

I'll keep pushing the bit higher until hopefully I can delete the global
`cl::opt` entirely.

llvm-svn: 234957
2015-04-15 00:10:50 +00:00
Rafael Espindola 5682ce2ceb Simplify use of formatted_raw_ostream.
formatted_raw_ostream is a wrapper over another stream to add column and line
number tracking.

It is used only for asm printing.

This patch moves the its creation down to where we know we are printing
assembly. This has the following advantages:

* Simpler lifetime management: std::unique_ptr
* We don't compute column and line number of object files :-)

llvm-svn: 234535
2015-04-09 21:06:08 +00:00
Rafael Espindola ee0dd4d289 This reverts commit r234460 and r234461.
Revert "Add classof implementations to the raw_ostream classes."
Revert "Use the cast machinery to remove dummy uses of formatted_raw_ostream."

The underlying issue can be fixed without classof.

llvm-svn: 234495
2015-04-09 15:54:59 +00:00
Rafael Espindola 132381f981 Use the cast machinery to remove dummy uses of formatted_raw_ostream.
If we know we are producing an object, we don't need to wrap the stream
in a formatted_raw_ostream anymore.

llvm-svn: 234461
2015-04-09 02:28:12 +00:00
Rafael Espindola 0d68b4c5ed Fix PR23045.
Keep a note in the materializer that we are stripping debug info so that
user doing a lazy read of the module don't hit outdated formats.

Thanks to Duncan for suggesting the fix.

llvm-svn: 233603
2015-03-30 21:36:43 +00:00
Rafael Espindola 2fcfb5e5c7 Work around pr23045 and make it easier to reproduce.
Dropping old debug format requires the entire module to be read upfront.

This was failing only with the gold plugin, but that is just because
llvm-link was not upgrading metadata.

The new testcase using llvm-link shows the problem.

llvm-svn: 233381
2015-03-27 15:55:06 +00:00
Peter Collingbourne 070843d60b libLTO, llvm-lto, gold: Introduce flag for controlling optimization level.
This change also introduces a link-time optimization level of 1. This
optimization level runs only the globaldce pass as well as cleanup passes for
passes that run at -O0, specifically simplifycfg which cleans up lowerbitsets.

http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150316/266951.html

llvm-svn: 232769
2015-03-19 22:01:00 +00:00
Rafael Espindola cba833a09d Be lazy about loading metadata in IRObjectFile.
This speeds up llvm-ar building lib64/libclangSema.a with debug IR files
from 8.658015807 seconds to just 0.351036519 seconds :-)

llvm-svn: 232221
2015-03-13 21:54:20 +00:00
Rafael Espindola 265ffbeb0c Fix the build of the gold-plugin and examples.
llvm-svn: 231279
2015-03-04 19:15:29 +00:00
Rafael Espindola f3f185486c Bring r231132 back with a fix.
The issue was that we were always printing the remarks. Fix that and add a test
showing that it prints nothing if -pass-remarks is not given.

Original message:
Correctly handle -pass-remarks in the gold plugin.

llvm-svn: 231273
2015-03-04 18:51:45 +00:00
NAKAMURA Takumi 84a9697c17 Revert r231132, "Correctly handle -pass-remarks in the gold plugin.", for now, to suppress log floodng in LTO.
llvm-svn: 231253
2015-03-04 16:24:28 +00:00
Rafael Espindola 84483d247f Correctly handle -pass-remarks in the gold plugin.
llvm-svn: 231132
2015-03-03 21:11:13 +00:00
Rafael Espindola 503f883b95 Add r230655 back with a fix.
The issue is that now we have a diag handler during optimizations
and get forward every optimization remark, flooding stdout.

The same filtering should probably be done with or without a
custom handler, but for now just ignore remarks.

Original message:

gold-plugin: "Upgrade" debug info and handle its warnings.

The gold plugin never calls MaterializeModule, so any old debug info
was not deleted and could cause crashes.

Now that it is being "upgraded", the plugin also has to handle warnings
and create Modules with a nice id (it shows in the warning).

llvm-svn: 230991
2015-03-02 19:08:03 +00:00
NAKAMURA Takumi 0f480f5010 Revert r230655, "gold-plugin: "Upgrade" debug info and handle its warnings."
It emits *millions of warnings* during selfhosting LTO build, to choke the buildbot with gigbytes of log.

llvm-svn: 230885
2015-03-01 04:16:28 +00:00
Rafael Espindola 7360fb6206 gold-plugin: "Upgrade" debug info and handle its warnings.
The gold plugin never calls MaterializeModule, so any old debug info
was not deleted and could cause crashes.

Now that it is being "upgraded", the plugin also has to handle warnings
and create Modules with a nice id (it shows in the warning).

llvm-svn: 230655
2015-02-26 18:24:37 +00:00
Rafael Espindola 85d8509267 Set the datalayout in the gold plugin.
This fixes the gold tests after r230054.

llvm-svn: 230098
2015-02-21 00:13:15 +00:00
Chandler Carruth edd92948d1 [gold] Consolidate the gold plugin options and actually search for
a gold binary explicitly. Substitute this binary into the tests rather
than just directly executing the 'ld' binary.

This should allow folks to inject a cross compiling gold binary, or in
my case to use a gold binary built and installed somewhere other than
/usr/bin/ld. It should also allow the tests to find 'ld.gold' so that
things work even if gold isn't the default on the system.

I've only stubbed out support in the makefile to preserve the existing
behavior with none of the fancy logic. If someone else wants to add
logic here, they're welcome to do so.

llvm-svn: 229251
2015-02-14 09:43:57 +00:00
Chandler Carruth 5700b3798f [PM] Fix a compile error I introduced in r229094 and didn't notice
because I didn't have binutils set up properly to build the gold plugin.

Fixes PR22581 which was filed because this broke the build for folks
relying on the plugin. Very sorry! =]

I've gotten the plugin stuff building now as well so it shouldn't keep
happening.

llvm-svn: 229156
2015-02-13 21:10:58 +00:00
Chandler Carruth 30d69c2e36 [PM] Remove the old 'PassManager.h' header file at the top level of
LLVM's include tree and the use of using declarations to hide the
'legacy' namespace for the old pass manager.

This undoes the primary modules-hostile change I made to keep
out-of-tree targets building. I sent an email inquiring about whether
this would be reasonable to do at this phase and people seemed fine with
it, so making it a reality. This should allow us to start bootstrapping
with modules to a certain extent along with making it easier to mix and
match headers in general.

The updates to any code for users of LLVM are very mechanical. Switch
from including "llvm/PassManager.h" to "llvm/IR/LegacyPassManager.h".
Qualify the types which now produce compile errors with "legacy::". The
most common ones are "PassManager", "PassManagerBase", and
"FunctionPassManager".

llvm-svn: 229094
2015-02-13 10:01:29 +00:00
Michael Kuperstein a07d9b9a4b gold-plugin: delete the output file for OT_DISABLE
bfd creates the output file early, so calling exit(0) is not enough, the file needs to be explicitly deleted.

Patch by: H.J. Lu <hjl.tools@gmail.com>

llvm-svn: 228946
2015-02-12 18:21:50 +00:00
Jan Wen Voung c11b45a2ea Gold-plugin: Broaden scope of get/release_input_file to scope of Module.
Summary:
Move calls to get_input_file and release_input_file out of
getModuleForFile(). Otherwise release_input_file may end up
unmapping a view of the file while the view is still being
used by the Module (on 32-bit hosts).

Fix for PR22482.

Test Plan: Add test using --no-map-whole-files.

Reviewers: rafael, nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7539

llvm-svn: 228842
2015-02-11 16:12:50 +00:00
NAKAMURA Takumi b0a52838fa gold-plugin.cpp: Fixup r227599 corresponding to r227685 and r227731 -- Don't lose DataLayoutPass.
llvm-svn: 227783
2015-02-02 05:47:30 +00:00
Alexey Samsonov 5ce244889c Fixup gold-plugin after r227576.
llvm-svn: 227599
2015-01-30 19:14:04 +00:00
Sylvestre Ledru 450f97dcb9 Update of the gold-plugin.cpp code to match Chandler's changes (r226981)
llvm-svn: 227004
2015-01-24 13:59:08 +00:00
Chandler Carruth 62d4215baa [PM] Move TargetLibraryInfo into the Analysis library.
While the term "Target" is in the name, it doesn't really have to do
with the LLVM Target library -- this isn't an abstraction which LLVM
targets generally need to implement or extend. It has much more to do
with modeling the various runtime libraries on different OSes and with
different runtime environments. The "target" in this sense is the more
general sense of a target of cross compilation.

This is in preparation for porting this analysis to the new pass
manager.

No functionality changed, and updates inbound for Clang and Polly.

llvm-svn: 226078
2015-01-15 02:16:27 +00:00
Rafael Espindola 9e3e53f6dd Fix linking of shared libraries.
In shared libraries the plugin can see non-weak declarations that are still
undefined.

llvm-svn: 226031
2015-01-14 20:08:46 +00:00
Rafael Espindola 0fd9e5f719 Fix handling of extern_weak. This was broken by r225983.
llvm-svn: 226026
2015-01-14 19:43:32 +00:00
Rafael Espindola 5ca7fa15fd Handle a symbol being undefined.
This can happen if:
* It is present in a comdat in one file.
* It is not present in the comdat of the file that is kept.
* Is is not used.

This should fix the LTO boostrap.

Thanks to Takumi NAKAMURA for setting up the bot!

llvm-svn: 225983
2015-01-14 13:53:50 +00:00
Rafael Espindola d0b23bef6f Use the DiagnosticHandler to print diagnostics when reading bitcode.
The bitcode reading interface used std::error_code to report an error to the
callers and it is the callers job to print diagnostics.

This is not ideal for error handling or diagnostic reporting:

* For error handling, all that the callers care about is 3 possibilities:
  * It worked
  * The bitcode file is corrupted/invalid.
  * The file is not bitcode at all.

* For diagnostic, it is user friendly to include far more information
  about the invalid case so the user can find out what is wrong with the
  bitcode file. This comes up, for example, when a developer introduces a
  bug while extending the format.

The compromise we had was to have a lot of error codes.

With this patch we use the DiagnosticHandler to communicate with the
human and std::error_code to communicate with the caller.

This allows us to have far fewer error codes and adds the infrastructure to
print better diagnostics. This is so because the diagnostics are printed when
he issue is found. The code that detected the problem in alive in the stack and
can pass down as much context as needed. As an example the patch updates
test/Bitcode/invalid.ll.

Using a DiagnosticHandler also moves the fatal/non-fatal error decision to the
caller. A simple one like llvm-dis can just use fatal errors. The gold plugin
needs a bit more complex treatment because of being passed non-bitcode files. An
hypothetical interactive tool would make all bitcode errors non-fatal.

llvm-svn: 225562
2015-01-10 00:07:30 +00:00
Rafael Espindola 538c9a88d9 Fix a leak found by asan.
llvm-svn: 224776
2014-12-23 18:18:37 +00:00
Rafael Espindola 4d47f7f52b Simplify the handling of aliases in the gold plugin.
The complicated situation is when we have to keep an alias but drop a GV
that is part of the aliasee.

We used to clone the dropped GV and make the clone internal. This is wasteful
as we know the original will be dropped.

With this patch what is done instead is set the linkage of the original to
internal and replace all uses (but the one in the alias) with a new
declaration that takes the name of the old GV. This saves us from having
to copy the body.

llvm-svn: 223863
2014-12-10 00:09:35 +00:00
Rafael Espindola 5dec7eaae2 Rename createIRObjectFile to just create.
It is a static method of IRObjectFile, so having to use
IRObjectFile::createIRObjectFile was redundant.

llvm-svn: 223822
2014-12-09 20:36:13 +00:00
Rafael Espindola a4f104b2ce Remember the unmangled name in the plugin.
This allows it to work with non trivial manglings like the one in COFF.

Amusingly, this can be tested with gold, as emit-llvm causes the plugin to
exit before any COFF is generated.

llvm-svn: 223790
2014-12-09 16:50:57 +00:00
Rafael Espindola 527e846ef7 Don't lookup an object symbol name in the module.
Instead, walk the obj symbol list in parallel to find the GV. This shouldn't
change anything on ELF where global symbols are not mangled, but it is a step
toward supporting other object formats.

Gold itself is ELF only, but bfd ld supports COFF and the logic in the gold
plugin could be reused on lld.

llvm-svn: 223780
2014-12-09 16:13:59 +00:00
Rafael Espindola 9c8ebeb03d Be less conservative about when we build the gold plugin.
It is only build if LLVM_BINUTILS_INCDIR is explicitly given, so there is
no point in having extra restrictions.

llvm-svn: 223481
2014-12-05 17:25:52 +00:00
Rafael Espindola 947bdb69cb gold plugin: call llvm_shutdown so that -stats works.
llvm-svn: 222787
2014-11-25 20:52:49 +00:00
Rafael Espindola 6953a3a6e0 Add a disable-output option to the gold plugin.
This corresponds to the opt option and is handy for profiling.

llvm-svn: 222687
2014-11-24 21:18:14 +00:00
Duncan P. N. Exon Smith f6ab47038c gold-plugin: Fix typo in error message
Spotted while reading code.

llvm-svn: 222395
2014-11-19 22:39:21 +00:00
Rafael Espindola b14407a300 Fix the build of the gold plugin.
I did the previous patch on OS X and didn't noticed the issue.

llvm-svn: 221070
2014-11-01 23:49:44 +00:00
Rafael Espindola 246c4fb5d9 Remove redundant calls to isMaterializable.
This removes calls to isMaterializable in the following cases:

* It was redundant with a call to isDeclaration now that isDeclaration returns
  the correct answer for materializable functions.
* It was followed by a call to Materialize. Just call Materialize and check EC.

llvm-svn: 221050
2014-11-01 16:46:18 +00:00
Rafael Espindola 919fb535a0 Enable the slp vectorizer in the gold plugin.
llvm-svn: 220887
2014-10-30 00:38:54 +00:00
Rafael Espindola 8391dbd1c6 Enable the loop vectorizer in the gold plugin.
llvm-svn: 220886
2014-10-30 00:11:24 +00:00
Rafael Espindola 4a3b6cf3c1 Replace also-emit-llvm with save-temps.
The also-emit-llvm option only supported getting the IR before optimizations.
This patch replaces it with a more generic save-temps option that saves the IR
both before and after optimizations.

llvm-svn: 220885
2014-10-29 23:54:45 +00:00
Rafael Espindola 8f2d615252 Remove unused variable.
llvm-svn: 220610
2014-10-25 04:07:53 +00:00
Rafael Espindola d12b4a334b Update the error handling of lib/Linker.
Instead of passing a std::string&, use the new diagnostic infrastructure.

llvm-svn: 220608
2014-10-25 04:06:10 +00:00
Rafael Espindola 5a52e6dc9e Modernize the error handling of the Materialize function.
llvm-svn: 220600
2014-10-24 22:50:48 +00:00
Rafael Espindola d4bcefc7d9 Don't ever call materializeAllPermanently during LTO.
To do this, change the representation of lazy loaded functions.

The previous representation cannot differentiate between a function whose body
has been removed and one whose body hasn't been read from the .bc file. That
means that in order to drop a function, the entire body had to be read.

llvm-svn: 220580
2014-10-24 18:13:04 +00:00
Rafael Espindola b0fc4cf3b9 Fix a gcc warning.
Thanks to Filipe Cabecinhas for the report.

llvm-svn: 220361
2014-10-22 02:23:31 +00:00
Rafael Espindola 2754dbb4ab Fix gcc warning in gold-plugin.cpp.
Patch by Markus Trippelsdorf!

llvm-svn: 219459
2014-10-10 00:48:13 +00:00
Rafael Espindola dfc7ed7ad0 gold plugin: Handle gold selecting a linkonce GV when a weak is present.
The plugin API doesn't have the notion of linkonce, only weak. It is up to the
plugin to figure out if a symbol used only for the symbol table can be dropped.
In particular, it has to avoid dropping a linkonce_odr selected by gold if there
is also a weak_odr.

llvm-svn: 219188
2014-10-07 04:06:13 +00:00
Rafael Espindola cb69583c50 gold plugin: create internal replacement with original linkage first.
The call to copyAttributesFrom will copy the visibility, which might assert
if it were to produce something invalid like "internal hidden". We avoid it
by first creating the replacement with the original linkage and then setting
it to internal affter the call to copyAttributesFrom.

llvm-svn: 219184
2014-10-07 03:19:55 +00:00
Rafael Espindola 93aec71ba9 gold plugin: Remap function arguments when creating a replacement function.
When creating an internal function replacement for use in an alias we were
not remapping the argument uses in the instructions to point to the new
arguments.

llvm-svn: 219177
2014-10-07 00:47:38 +00:00
Peter Collingbourne 10039c02ea LTO: introduce object file-based on-disk module format.
This format is simply a regular object file with the bitcode stored in a
section named ".llvmbc", plus any number of other (non-allocated) sections.

One immediate use case for this is to accommodate compilation processes
which expect the object file to contain metadata in non-allocated sections,
such as the ".go_export" section used by some Go compilers [1], although I
imagine that in the future we could consider compiling parts of the module
(such as large non-inlinable functions) directly into the object file to
improve LTO efficiency.

[1] http://golang.org/doc/install/gccgo#Imports

Differential Revision: http://reviews.llvm.org/D4371

llvm-svn: 218078
2014-09-18 21:28:49 +00:00
Rafael Espindola 51bd8ee309 Internalize common symbols when we can.
This fixes pr20974.

llvm-svn: 217981
2014-09-17 20:41:13 +00:00
Rafael Espindola c435adcde0 Add doInitialization/doFinalization to DataLayoutPass.
With this a DataLayoutPass can be reused for multiple modules.

Once we have doInitialization/doFinalization, it doesn't seem necessary to pass
a Module to the constructor.

Overall this change seems in line with the idea of making DataLayout a required
part of Module. With it the only way of having a DataLayout used is to add it
to the Module.

llvm-svn: 217548
2014-09-10 21:27:43 +00:00
Rafael Espindola 71143ed24b Remember to eraseFromParent after replaceAllUsesWith.
llvm-svn: 217536
2014-09-10 19:39:41 +00:00
Rafael Espindola 890db27b67 Handle common linkage correctly in the gold plugin.
This is the plugin version of pr20882.

This handles the case of every common symbol being in the IR. We will need some
support from gold to handle the case where some symbols are in ELF and some in
the IR.

llvm-svn: 217458
2014-09-09 20:08:22 +00:00
David Blaikie 10a27df8ff unique_ptrify IRObjectFile::createIRObjectFile
I took a guess at the changes to the gold plugin, because that doesn't
seem to build by default for me. Not sure what dependencies I might be
missing for that.

llvm-svn: 217056
2014-09-03 17:59:23 +00:00
Rafael Espindola 688121571a Pass a && to getLazyBitcodeModule.
This forces callers to use std::move when calling it. It is somewhat odd to have
code with std::move that doesn't always move, but it is also odd to have code
without std::move that sometimes moves.

llvm-svn: 217049
2014-09-03 17:31:46 +00:00
Rafael Espindola eeec8e63c0 Don't create a MemoryBuffer just to get the MemoryBufferRef. NFC.
llvm-svn: 216608
2014-08-27 20:25:55 +00:00
David Blaikie dfbe3d6b17 Convert a few more cases of direct intialization of unique_ptrs from MemoryBuffer::getMemBuffer to move initialization now that it returns by unique_ptr instead of raw pointer.
Cleanup/improvements following r216583.

llvm-svn: 216605
2014-08-27 20:14:18 +00:00
Rafael Espindola 3560ff2c1f Return a std::unique_ptr when creating a new MemoryBuffer.
llvm-svn: 216583
2014-08-27 20:03:13 +00:00
Rafael Espindola e2c1d77fb4 Pass a std::unique_ptr<MemoryBuffer>& to getLazyBitcodeModule.
By taking a reference we can do the ownership transfer in one place instead of
expecting every caller to do it.

llvm-svn: 216492
2014-08-26 22:00:09 +00:00
Rafael Espindola 3fd1e9933f Modernize raw_fd_ostream's constructor a bit.
Take a StringRef instead of a "const char *".
Take a "std::error_code &" instead of a "std::string &" for error.

A create static method would be even better, but this patch is already a bit too
big.

llvm-svn: 216393
2014-08-25 18:16:47 +00:00
Rafael Espindola f7ecb11572 Add support for comdats to the gold plugin.
There are two parts to this. First, the plugin needs to tell gold the comdat by
setting comdat_key.

What gets things a bit more complicated is that gold only seems
symbols. In particular, if A is an alias to B, it only sees the symbols
A and B. It can then ask us to keep symbol A but drop symbol B. What
we have to do instead is to create an internal version of B and make A
an alias to that.

At some point some of this logic should be moved to lib/Linker so that
we don't map a Constant to an internal version just to have lib/Linker
map that again to the destination module.

The reason for implementing this in tools/gold for now is simplicity.
With it in place it should be possible to update clang to use comdats
for constructors and destructors on ELF without breaking the LTO
bootstrap. Once that is done I intend to come back and improve the
interface lib/Linker exposes.

llvm-svn: 216302
2014-08-22 23:26:10 +00:00