Commit Graph

503 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith b42fa2e5c6 BitcodeWriter: Reuse writeMetadataRecords, NFC
Change writeFunctionMetadata to call writeMetadataRecords.  For now
there's no functionality change, but makes it easy to serialize other
types of metadata in the function block in the future.

llvm-svn: 264557
2016-03-27 23:59:32 +00:00
Duncan P. N. Exon Smith cffd8cb9dc BitcodeWriter: Rename some functions for consistency, NFC
To match writeMetadataRecords, writeNamedMetadata and
writeMetadataStrings, change:

    WriteModuleMetadata        => writeModuleMetadata
    WriteFunctionLocalMetadata => writeFunctionMetadata
    Write##CLASS               => write##CLASS

The only major change is "FunctionLocal" => "Function".  The point is to
be less specific, in preparation for emitting normal metadata records
inside function metadata blocks (currently we only emit
`LocalAsMetadata` there).

llvm-svn: 264556
2016-03-27 23:56:04 +00:00
Duncan P. N. Exon Smith 80d153f6aa BitcodeWriter: Split out writeMetadataRecords, NFC
Besides being a nice cleanup, this is preparation for reusing the code
in function metadata blocks.

llvm-svn: 264555
2016-03-27 23:53:30 +00:00
Duncan P. N. Exon Smith 5465f0adc4 BitcodeWriter: Restructure WriteFunctionLocalMetadata, NFC
Use an early return to simplify logic.

llvm-svn: 264554
2016-03-27 23:38:36 +00:00
Duncan P. N. Exon Smith 2766e4d488 BitcodeWriter: Simplify tracking of function-local metadata, NFC
We don't really need a separate vector here; instead, point at a range
inside the main MDs array.  This matches how r264551 references the
ranges of strings and non-strings.

llvm-svn: 264552
2016-03-27 23:22:31 +00:00
Duncan P. N. Exon Smith 6565a0d4b2 Reapply ~"Bitcode: Collect all MDString records into a single blob"
Spiritually reapply commit r264409 (reverted in r264410), albeit with a
bit of a redesign.

Firstly, avoid splitting the big blob into multiple chunks of strings.

r264409 imposed an arbitrary limit to avoid a massive allocation on the
shared 'Record' SmallVector.  The bug with that commit only reproduced
when there were more than "chunk-size" strings.  A test for this would
have been useless long-term, since we're liable to adjust the chunk-size
in the future.

Thus, eliminate the motivation for chunk-ing by storing the string sizes
in the blob.  Here's the layout:

    vbr6: # of strings
    vbr6: offset-to-blob
    blob:
       [vbr6]: string lengths
       [char]: concatenated strings

Secondly, make the output of llvm-bcanalyzer readable.

I noticed when debugging r264409 that llvm-bcanalyzer was outputting a
massive blob all in one line.  Past a small number, the strings were
impossible to split in my head, and the lines were way too long.  This
version adds support in llvm-bcanalyzer for pretty-printing.

    <STRINGS abbrevid=4 op0=3 op1=9/> num-strings = 3 {
      'abc'
      'def'
      'ghi'
    }

From the original commit:

Inspired by Mehdi's similar patch, http://reviews.llvm.org/D18342, this
should (a) slightly reduce bitcode size, since there is less record
overhead, and (b) greatly improve reading speed, since blobs are super
cheap to deserialize.

llvm-svn: 264551
2016-03-27 23:17:54 +00:00
Mehdi Amini 385cf28829 Rename ModuleSummaryIndex::modPathStringEntries() into modulePaths()
It now return the map instead of an iterator.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 264489
2016-03-26 03:35:38 +00:00
Teresa Johnson aae2610042 [ThinLTO] Rename edges() to calls() for clarity (NFC)
Helps distinguish from refs() which iterates over non-call references.

llvm-svn: 264445
2016-03-25 18:59:13 +00:00
Duncan P. N. Exon Smith fc8110041f Revert "Bitcode: Collect all MDString records into a single blob"
This reverts commit r264409 since it failed to bootstrap:
http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_build/8302/

llvm-svn: 264410
2016-03-25 15:22:27 +00:00
Duncan P. N. Exon Smith fdbf0a5af8 Bitcode: Collect all MDString records into a single blob
Optimize output of MDStrings in bitcode.  This emits them in big blocks
(currently 1024) in a pair of records:
  - BULK_STRING_SIZES: the sizes of the strings in the block, and
  - BULK_STRING_DATA: a single blob, which is the concatenation of all
    the strings.

Inspired by Mehdi's similar patch, http://reviews.llvm.org/D18342, this
should (a) slightly reduce bitcode size, since there is less record
overhead, and (b) greatly improve reading speed, since blobs are super
cheap to deserialize.

I needed to add support for blobs to streaming input to get the test
suite passing.
  - StreamingMemoryObject::getPointer reads ahead and returns the
    address of the blob.
  - To avoid a possible reallocation of StreamingMemoryObject::Bytes,
    BitstreamCursor::readRecord needs to move the call to JumpToEnd
    forward so that getPointer is the last bitstream operation.

llvm-svn: 264409
2016-03-25 14:40:18 +00:00
Duncan P. N. Exon Smith 68f5624356 Bitcode: Stop using MODULE_CODE_METADATA_VALUES
The motivation for MODULE_CODE_METADATA_VALUES was to enable an
-flto=thin scheme where:

 1. First, one function is cherry-picked from a bitcode file.
 2. Later, another function is cherry-picked.
 3. Later, ...
 4. Finally, the metadata needed by all the previous functions is
    loaded.

This was abandoned in favour of:

 1. Calculate the superset of functions needed from a Module.
 2. Link all functions at once.

Delayed metadata reading no longer serves a purpose.  It also adds
a few complication, since we can't count on metadata being properly
parsed when exiting the BitcodeReader.  After discussing with Teresa, we
agreed to remove it.

The code that depended on this was removed/updated in r264326.

llvm-svn: 264378
2016-03-25 01:29:50 +00:00
Duncan P. N. Exon Smith a5e25a5563 BitcodeWriter: Move abbreviation for GenericDINode; almost NFC
Simplify ValueEnumerator and WriteModuleMetadata by shifting the logic
for the METADATA_GENERIC_DEBUG abbreviation into WriteGenericDINode.
(This is just like r264302, but for GenericDINode.)

The only change is that the abbreviation is emitted later in the
bitcode, just before the first `GenericDINode` record.  This shouldn't
be observable though.

llvm-svn: 264303
2016-03-24 16:30:18 +00:00
Duncan P. N. Exon Smith 625fda2714 BitcodeWriter: Move abbreviation for DILocation; almost NFC
Simplify ValueEnumerator and WriteModuleMetadata by shifting the logic
for the METADATA_LOCATION abbreviation into WriteDILocation.

The only change is that the abbreviation is emitted later in the
bitcode, just before the first `DILocation` record.  This shouldn't be
observable though.

llvm-svn: 264302
2016-03-24 16:25:51 +00:00
Duncan P. N. Exon Smith f8ecdf5284 BitcodeWriter: Split out named metadata; almost NFC
Split writeNamedMetadata out of WriteModuleMetadata to write named
metadata, and createNamedMetadataAbbrev for the abbreviation.

There should be no effective functionality change, although the layout
of the bitcode will change.  Previously, the abbreviation was emitted at
the top of the block, but now it is delayed until immediately before the
named metadata records are emitted.

llvm-svn: 264301
2016-03-24 16:16:08 +00:00
Duncan P. N. Exon Smith 0b7243ee38 Bitcode: Module* -> Module&, NFC
llvm-svn: 264299
2016-03-24 16:01:46 +00:00
Easwaran Raman 12b79aa0f1 Add getBlockProfileCount method to BlockFrequencyInfo
Differential Revision: http://reviews.llvm.org/D18233

llvm-svn: 264179
2016-03-23 18:18:26 +00:00
Teresa Johnson 1396809b17 [ThinLTO] Record all global variable defs in the summary
Record all variable defs with a summary record to aid in building a
complete reference graph and locating constant variable defs to import.

llvm-svn: 263576
2016-03-15 19:35:45 +00:00
Teresa Johnson 2794f71575 BitcodeWriter dyn_cast cleanup for r263275 (NFC)
Address review suggestions from dblaikie: change a few dyn_cast to cast
and fold a cast into if condition.

llvm-svn: 263526
2016-03-15 02:41:29 +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
David Majnemer 90a021fb02 [Bitcode] Make writeComdats less strange
It had a weird artificial limitation on the write side: the comdat name
couldn't be bigger than 2**16.  However, the reader had no such
limitation.  Make the reader and the writer agree.

llvm-svn: 263377
2016-03-13 08:01:03 +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
Mehdi Amini 83efea89e8 Bitcode writer: fix a typo, using getName() instead of getSourceFileName()
When emitting the source filename, the encoding of the string
was checked against the name instead of the filename.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 261019
2016-02-16 22:07:03 +00:00
Teresa Johnson e1164de5d0 Restore "[ThinLTO] Use MD5 hash in function index." with fix
This restores commit r260408, along with a fix for a bot failure.

The bot failure was caused by dereferencing a unique_ptr in the same
call instruction parameter list where it was passed via std::move.
Apparently due to luck this was not exposed when I built the compiler
with clang, only with gcc.

llvm-svn: 260442
2016-02-10 21:55:02 +00:00