Commit Graph

1284 Commits

Author SHA1 Message Date
Mehdi Amini fdbb8f47eb Avoid temporary vector for sorting in BitcodeWriter
As suggested by Duncan, fixup for r269634 and r269635

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269715
2016-05-16 22:47:15 +00:00
Mehdi Amini 367577aab9 ThinLTO: fix non-determinism in bitcode writing
Calls are initialized from a DenseMap. We can sort them using the
value id to recover some determinism during serialization.

From: mehdi_amini <mehdi_amini@91177308-0d34-0410-b5e6-96231b3b80d8>
llvm-svn: 269638
2016-05-16 09:04:55 +00:00
Mehdi Amini fe97408495 Revert "ThinLTO: fix non-determinism in bitcode writing"
This reverts commit r269634, bots are broken.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269637
2016-05-16 09:04:50 +00:00
Mehdi Amini f606c8d633 ThinLTO: fix another non-determinism in bitcode writing
GlobalVars Refs are initialized from a DenseSet. We can sort them
using the value id to recover some determinism during serialization.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269635
2016-05-16 08:50:27 +00:00
Mehdi Amini 564c49a938 ThinLTO: fix non-determinism in bitcode writing
Calls are initialized from a DenseMap. We can sort them using the
value id to recover some determinism during serialization.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269634
2016-05-16 08:50:23 +00:00
Mehdi Amini 7c9ceb5cc8 ThinLTO: fix non-determinism in bitcode writing
Refs are initialized from a DenseSet. We can sort them using the
value id to recover some determinism during serialization.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 269629
2016-05-16 04:50:47 +00:00
Benjamin Kramer a65b610bd2 Move helper classes into anonymous namespaces. NFC.
llvm-svn: 269591
2016-05-15 15:18:11 +00:00
Teresa Johnson e518c800f6 [ThinLTO] Fix Windows debug failure in new iterator
This fixes a debug assert on Windows from the new iterator
implementation added in r269059. The Windows std::vector iterator
operator== checks in debug mode that the containers being iterated over
are the same, which they may not be.

Fixed by checking that we are iterating over the same container before
comparing the container iterators.

llvm-svn: 269232
2016-05-11 20:46:22 +00:00
Teresa Johnson 84174c3771 Restore "[ThinLTO] Emit individual index files for distributed backends"
This restores commit r268627:
    Summary:
    When launching ThinLTO backends in a distributed build (currently
    supported in gold via the thinlto-index-only plugin option), emit
    an individual index file for each backend process as described here:
    http://lists.llvm.org/pipermail/llvm-dev/2016-April/098272.html

    ...

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

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

llvm-svn: 269059
2016-05-10 13:48:23 +00:00
Adrian Prantl 85338cbdb6 Implement a safer bitcode upgrade for DISubprogram.
The bitcode upgrade I added for DISubprogram in r266446 was based on the
assumption that the CU node for the subprogram was already materialized by the
time the DISubprogram is visited. This assumption may not hold true as future
versions of LLVM may decide to write out bitcode in a different order. This
patch corrects this by introducing a versioning bit next to the distinct flag to
unambiguously differentiate the new from the old record layouts.

Note for people stabilizing LLVM out-of-tree: This patch introduces a bitcode
incompatibility with llvm trunk revisions from r266446 — this commit. (But
D19987 will ensure that it degrades gracefully).

http://reviews.llvm.org/D20004
rdar://problem/26074194

llvm-svn: 268816
2016-05-06 22:53:06 +00:00
Peter Collingbourne 832e7fa579 BitcodeWriter: Simplify. NFC.
llvm-svn: 268707
2016-05-06 02:41:23 +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
Teresa Johnson 9e95da77f9 [ThinLTO] Remove missed piece of lazy summary reading support (NFC)
Missed in r267097.

llvm-svn: 268597
2016-05-05 02:30:48 +00:00
Sjoerd Meijer 41beee6575 Clean up to avoid compiler warnings for casting away const qualifiers.
Differential Revision: http://reviews.llvm.org/D19598

llvm-svn: 267753
2016-04-27 18:35:02 +00:00
Teresa Johnson 02e98331c0 [ThinLTO] Use valueid instead of bitcode offsets in combined index file
Summary:
With the removal of support for lazy parsing of combined index summary
records (e.g. r267344), we no longer need to include the summary record
bitcode offset in the VST entries for definitions. Change the combined
index format to be similar to the per-module index format in using value
ids to cross-reference from the summary record to the VST entry (rather
than the summary record bitcode offset to cross-reference in the other
direction).

The visible changes are:
1) Add the value id to the combined summary records
2) Remove the summary offset from the combined VST records, which has
the following effects:
- No longer need the VST_CODE_COMBINED_GVDEFENTRY record, as all
  combined index VST entries now only contain the value id and
  corresponding GUID.
- No longer have duplicate VST entries in the case where there are
  multiple definitions of a symbol (e.g. weak/linkonce), as they all
  have the same value id and GUID.

An implication of #2 above is that in order to hook up an alias to the
correct aliasee based on the value id of the aliasee recorded in the
combined index alias record, we need to scan the entries in the index
for that GUID to find the one from the same module (i.e. the case where
there are multiple entries for the aliasee). But the reader no longer
has to maintain a special map to hook up the alias/aliasee.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19481

llvm-svn: 267712
2016-04-27 13:28:35 +00:00
Duncan P. N. Exon Smith 03a04a58ea BitcodeReader: Delay metadata parsing until reading a function body
There's hardly any functionality change here.  Instead of calling
materializeMetadata on the first call to materialize(GlobalValue*), wait
until the first one that's actually going to do something.  Noticed by
inspection; I don't have a concrete case where this makes a difference.

Added an assertion in materializeMetadata to be sure this (or a future
change) doesn't delay materializeMetadata after function-level metadata.

llvm-svn: 267345
2016-04-24 15:04:28 +00:00
Teresa Johnson 28e457bccd [ThinLTO] Remove GlobalValueInfo class from index
Summary:
Remove the GlobalValueInfo and change the ModuleSummaryIndex to directly
reference summary objects. The info structure was there to support lazy
parsing of the combined index summary objects, which is no longer
needed and not supported.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

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

llvm-svn: 267344
2016-04-24 14:57:11 +00:00
Aaron Ballman c79c2be7d2 Silence two C4806 warnings ('|': unsafe operation: no value of type 'bool' promoted to type 'const unsigned int' can equal the given constant). The fact that they trigger with this code seems like it may be a bug, but the warning itself is still generally useful enough to retain it for now.
llvm-svn: 267337
2016-04-24 13:03:20 +00:00
Duncan P. N. Exon Smith 5892c6b94b BitcodeReader: Fix some holes in upgrade from r267296
Add tests for some missing cases to bitcode upgrade in r267296.

  - DICompositeType with an 'elements:' field, which will cause it to be
    involved in a cycle after the upgrade.

  - A DIDerivedType that references a class in 'extraData:'.

I updated test/Bitcode/dityperefs-3.8.ll with the missing cases and
regenerated test/Bitcode/dityperefs-3.8.ll.bc.

llvm-svn: 267332
2016-04-24 06:52:01 +00:00
Mehdi Amini ca2c54e04e Add "hasSection" flag in the Summary
Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19405

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267329
2016-04-24 05:31:43 +00:00
Mehdi Amini c3ed48c1bd Reorganize GlobalValueSummary with a "Flags" bitfield.
Right now it only contains the LinkageType, but will be extended
with "hasSection", "isOptSize", "hasInlineAssembly", etc.

Differential Revision: http://reviews.llvm.org/D19404

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267319
2016-04-24 03:18:18 +00:00
Mehdi Amini 8fe6936e18 Add a version field in the bitcode for the summary
Differential Revision: http://reviews.llvm.org/D19456

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267318
2016-04-24 03:18:11 +00:00
Mehdi Amini ae64eafd31 Store and emit original name in combined index
Summary:
As discussed in D18298, some local globals can't
be renamed/promoted (because they have a section, or because
they are referenced from inline assembly).
To be able to detect naming collision, we need to keep around
the "GUID" using their original name without taking the linkage
into account.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19454

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267304
2016-04-23 23:38:17 +00:00
Duncan P. N. Exon Smith 69bdc8afa9 BitcodeReader: Avoid std::vector with non-movable types from r267296
r267298 didn't quite fix the build errors.  Use SmallVector instead of
std::vector, the latter of which I think is trying to maintain a strong
exception safety guarantee.

http://lab.llvm.org:8011/builders/lldb-amd64-ninja-freebsd11/builds/6228

llvm-svn: 267299
2016-04-23 21:36:59 +00:00
Duncan P. N. Exon Smith ece57ddd56 BitcodeReader: Avoid non-moving std::piecewise_construct from r267296
Not exactly sure why the host tries to use a copy constructor here, but
it's easy enough to work around it.

http://lab.llvm.org:8011/builders/lldb-amd64-ninja-freebsd11/builds/6227

llvm-svn: 267298
2016-04-23 21:23:41 +00:00
Duncan P. N. Exon Smith a59d3e5af8 DebugInfo: Remove MDString-based type references
Eliminate DITypeIdentifierMap and make DITypeRef a thin wrapper around
DIType*.  It is no longer legal to refer to a DICompositeType by its
'identifier:', and DIBuilder no longer retains all types with an
'identifier:' automatically.

Aside from the bitcode upgrade, this is mainly removing logic to resolve
an MDString-based reference to an actualy DIType.  The commits leading
up to this have made the implicit type map in DICompileUnit's
'retainedTypes:' field superfluous.

This does not remove DITypeRef, DIScopeRef, DINodeRef, and
DITypeRefArray, or stop using them in DI-related metadata.  Although as
of this commit they aren't serving a useful purpose, there are patchces
under review to reuse them for CodeView support.

The tests in LLVM were updated with deref-typerefs.sh, which is attached
to the thread "[RFC] Lazy-loading of debug info metadata":

  http://lists.llvm.org/pipermail/llvm-dev/2016-April/098318.html

llvm-svn: 267296
2016-04-23 21:08:00 +00:00
Duncan P. N. Exon Smith 30805b2417 BitcodeWriter: Emit uniqued subgraphs after all distinct nodes
Since forward references for uniqued node operands are expensive (and
those for distinct node operands are cheap due to
DistinctMDOperandPlaceholder), minimize forward references in uniqued
node operands.

Moreover, guarantee that when a cycle is broken by a distinct node, none
of the uniqued nodes have any forward references.  In
ValueEnumerator::EnumerateMetadata, enumerate uniqued node subgraphs
first, delaying distinct nodes until all uniqued nodes have been
handled.  This guarantees that uniqued nodes only have forward
references when there is a uniquing cycle (since r267276 changed
ValueEnumerator::organizeMetadata to partition distinct nodes in front
of uniqued nodes as a post-pass).

Note that a single uniqued subgraph can hit multiple distinct nodes at
its leaves.  Ideally these would themselves be emitted in post-order,
but this commit doesn't attempt that; I think it requires an extra pass
through the edges, which I'm not convinced is worth it (since
DistinctMDOperandPlaceholder makes forward references quite cheap
between distinct nodes).

I've added two testcases:

  - test/Bitcode/mdnodes-distinct-in-post-order.ll is just like
    test/Bitcode/mdnodes-in-post-order.ll, except with distinct nodes
    instead of uniqued ones.  This confirms that, in the absence of
    uniqued nodes, distinct nodes are still emitted in post-order.

  - test/Bitcode/mdnodes-distinct-nodes-break-cycles.ll is the minimal
    example where a naive post-order traversal would cause one uniqued
    node to forward-reference another.  IOW, it's the motivating test.

llvm-svn: 267278
2016-04-23 04:59:22 +00:00
Duncan P. N. Exon Smith 498b4977ba Avoid MSVC failure with default arguments in lambdas from r267270
http://lab.llvm.org:8011/builders/clang-x64-ninja-win7/builds/11700

llvm-svn: 267277
2016-04-23 04:52:47 +00:00
Duncan P. N. Exon Smith 1483fff271 BitcodeWriter: Emit distinct nodes before uniqued nodes
When an operand of a distinct node hasn't been read yet, the reader can
use a DistinctMDOperandPlaceholder.  This is much cheaper than forward
referencing from a uniqued node.  Change
ValueEnumerator::organizeMetadata to partition distinct nodes and
uniqued nodes to reduce the overhead of cycles broken by distinct nodes.

Mehdi measured this for me; this removes most of the RAUW from the
importing step of -flto=thin, even after a WIP patch that removes
string-based DITypeRefs (introducing many more cycles to the metadata
graph).

llvm-svn: 267276
2016-04-23 04:42:39 +00:00
Teresa Johnson c814e0c1fd Address comments.
llvm-svn: 267274
2016-04-23 04:31:20 +00:00
Teresa Johnson 37687f3911 Refactor bitcode writer into classes (NFC)
Summary:
As discussed in on the mailing list yesterday, I have refactored
BitcodeWriter.cpp to use classes to manage the bitcode writing process,
instead of passing around long lists of parameters between static
functions. See:
  http://lists.llvm.org/pipermail/llvm-dev/2016-April/098610.html

I created a parent BitcodeWriter class to own the BitstreamWriter,
write the header, and contain the main entry point into the writing
process. There are two derived classes, one for writing a module and one
for writing a combined index file (for ThinLTO), which manage the
writing process specific to those bitcode file types.

I also changed the functions to conform to LLVM coding standards
(lowercase function name first letter). The only two routines that still
start with an uppercase letter are the two external interfaces, which
can be fixed as a follow-on (I wanted to keep this round just within
BitcodeWriter.cpp).

Reviewers: dexonsmith, joker.eph

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19447

llvm-svn: 267273
2016-04-23 04:30:47 +00:00
Duncan P. N. Exon Smith e9f85c482b Avoid ternery statement to please g++ after r267270, NFC
http://bb.pgr.jp/builders/cmake-llvm-x86_64-linux/builds/36074

llvm-svn: 267272
2016-04-23 04:23:57 +00:00
Duncan P. N. Exon Smith d9bbdce715 ValueEnumerator: Use std::find_if, NFC
Mehdi's pattern recognition pulled this one out.  This is cleaner with
std::find_if than with the strange helper function that took an iterator
by reference and updated it.

llvm-svn: 267271
2016-04-23 04:22:38 +00:00
Duncan P. N. Exon Smith 4b1bc647f0 BitcodeReader: Avoid referencing unresolved nodes from distinct ones
Each reference to an unresolved MDNode is expensive, since the RAUW
support in MDNode uses a separate allocation and side map.  Since
a distinct MDNode doesn't require its operands on creation (unlike
uniuqed nodes, there's no need to check for structural equivalence),
use nullptr for any of its unresolved operands.  Besides reducing the
burden on MDNode maps, this can avoid allocating temporary MDNodes in
the first place.

We need some way to track operands.  Invent DistinctMDOperandPlaceholder
for this purpose, which is a Metadata subclass that holds an ID and
points at its single user.  DistinctMDOperandPlaceholder::replaceUseWith
is just like RAUW, but its name highlights that there is only ever
exactly one use.

There is no support for moving (or, obviously, copying) these.  Move
support would be possible but expensive; leaving it unimplemented
prevents user error.  In the BitcodeReader I originally considered
allocating on a BumpPtrAllocator and keeping a vector of pointers to
them, and then I realized that std::deque implements exactly this.

A couple of obvious follow-ups:

  - Change ValueEnumerator to emit distinct nodes first to take more
    advantage of this optimization.  (How convenient... I think I might
    have a couple of patches for this.)

  - Change DIBuilder and its consumers (like CGDebugInfo in clang) to
    use something like this when constructing debug info in the first
    place.

llvm-svn: 267270
2016-04-23 04:15:56 +00:00
Duncan P. N. Exon Smith 30ab4b4788 BitcodeReader: Consistently use IsDistinct, NFC
Consistently use the IsDistinct variable and start relying on it in
GET_OR_DISTINCT.  This change has NFC, but prepares for using IsDistinct
to optimize the behaviour of the getMD() and getMDOrNull() helpers.

llvm-svn: 267268
2016-04-23 04:01:57 +00:00
Duncan P. N. Exon Smith 004509dca1 BitcodeReader: Use getMD/getMDOrNull helpers consistently, almost NFC
The only functionality change was removing an error check from the
BitcodeReader (and an assertion from DILocation::getImpl) that is
already caught by Verifier::visitDILocation.  The Verifier is a better
place for this anyway, and being inconsistent with other subclasses of
MDNode isn't serving anyone.

llvm-svn: 267267
2016-04-23 03:55:14 +00:00
Duncan P. N. Exon Smith 71480bd0c7 ValueMapper/Enumerator: Clean up code in post-order traversals, NFC
Re-layer the functions in the new (i.e., newly correct) post-order
traversals in ValueEnumerator (r266947) and ValueMapper (r266949).
Instead of adding a node to the worklist in a helper function and
returning a flag to say what happened, return the node itself.  This
makes the code way cleaner: the worklist is local to the main function,
there is no flag for an early loop exit (since we can cleanly bury the
loop), and it's perfectly clear when pointers into the worklist might be
invalidated.

I'm fixing both algorithms in the same commit to avoid repeating the
commit message; if you take the time to understand one the other should
be easy.  The diff itself isn't entirely obvious since the traversals
have some noise (i.e., things to do), but here's the high-level change:

    auto helper = [&WL](T *Op) {     auto helper = [](T **&I, T **E) {
                                 =>    while (I != E) {
      if (shouldVisit(Op)) {             T *Op = *I++;
        WL.push(Op, Op->begin());        if (shouldVisit(Op)) {
        return true;                       return Op;
      }                                }
      return false;                    return nullptr;
    };                               };
                                 =>
    WL.push(S, S->begin());          WL.push(S, S->begin());
    while (!empty()) {               while (!empty()) {
      auto *N = WL.top().N;            auto *N = WL.top().N;
      auto *&I = WL.top().I;           auto *&I = WL.top().I;
      bool DidChange = false;
      while (I != N->end())
        if (helper(*I++)) {      =>    if (T *Op = helper(I, N->end()) {
          DidChange = true;              WL.push(Op, Op->begin());
          break;                         continue;
        }                              }
      if (DidChange)
        continue;

      POT.push(WL.pop());        =>    POT.push(WL.pop());
    }                                }

Thanks to Mehdi for helping me find a better way to layer this.

llvm-svn: 267099
2016-04-22 02:33:06 +00:00
Teresa Johnson 6fb3f19959 [ThinLTO] Remove unused/incomplete lazy summary reading support (NFC)
This removes the interfaces added (and not yet complete) to support
lazy reading of summaries. This support is not expected to be needed
since we are moving to a model where the full index is only being
traversed in the thin link step, instead of the back ends.

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

llvm-svn: 267097
2016-04-22 01:52:00 +00:00
Duncan P. N. Exon Smith c196531ef3 BitcodeWriter: Emit metadata in post-order (again)
Emit metadata nodes in post-order.  The iterative algorithm from r266709
failed to maintain this property.  After understanding my mistake, it
wasn't too hard to write a test with llvm-bcanalyzer (and I've actually
made this change once before: see r220340).

This also reverts the "noisy" testcase change from r266709.  That should
have been more of a red flag :/.

Note: The same bug crept into the ValueMapper in r265456.  I'm still
working on the fix.

llvm-svn: 266947
2016-04-21 01:55:12 +00:00
Duncan P. N. Exon Smith 3c406c2da5 IR: Use SmallVector instead of std::vector of TrackingMDRef
Don't use std::vector<TrackingMDRef>, since (at least in some versions
of libc++) std::vector apparently copies values on grow operations
instead of moving them.  Found this when I was temporarily deleting the
copy constructor for TrackingMDRef to investigate a performance
bottleneck.

llvm-svn: 266909
2016-04-20 20:14:09 +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
Duncan P. N. Exon Smith 9738602869 IR: Enable debug info type ODR uniquing for forward decls
Add a new method, DICompositeType::buildODRType, that will create or
mutate the DICompositeType for a given ODR identifier, and use it in
LLParser and BitcodeReader instead of DICompositeType::getODRType.

The logic is as follows:

  - If there's no node, create one with the given arguments.
  - Else, if the current node is a forward declaration and the new
    arguments would create a definition, mutate the node to match the
    new arguments.
  - Else, return the old node.

This adds a missing feature supported by the current DITypeIdentifierMap
(which I'm slowly making redudant).  The only remaining difference is
that the DITypeIdentifierMap has a "the-last-one-wins" rule, whereas
DICompositeType::buildODRType has a "the-first-one-wins" rule.

For now I'm leaving behind DICompositeType::getODRType since it has
obvious, low-level semantics that are convenient for unit testing.

llvm-svn: 266786
2016-04-19 18:00:19 +00:00
Duncan P. N. Exon Smith 0b0271ef97 IR: getOrInsertODRUniquedType => DICompositeType::getODRType, NFC
Lift the API for debug info ODR type uniquing up a layer.  Instead of
clients managing the map directly on the LLVMContext, add a static
method to DICompositeType called getODRType and handle the map in the
background.  Also adds DICompositeType::getODRTypeIfExists, so far just
for convenience in the unit tests.

This simplifies the logic in LLParser and BitcodeReader.  Because of
argument spam there are actually a few more lines of code now; I'll see
if I come up with a reasonable way to clean that up.

llvm-svn: 266742
2016-04-19 14:55:09 +00:00
Duncan P. N. Exon Smith 86f1bf98dc IR: Require DICompositeType for ODR uniquing type map
Tighten up the API for debug info ODR type uniquing in LLVMContext.  The
only reason to allow other DIType subclasses is to make the unit tests
prettier :/.

llvm-svn: 266737
2016-04-19 14:42:55 +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
Duncan P. N. Exon Smith 9695eb3239 BitcodeWriter: Break recursion when enumerating Metadata, almost NFC
Use a worklist instead of recursing through MDNode operands in
ValueEnumerator.  The actual record output order has changed slightly,
but otherwise there's no functionality change.

I had to update test/Bitcode/metadata-function-blocks.ll.  I renumbered
nodes so they continue to match the implicit record ids.

llvm-svn: 266709
2016-04-19 03:46:51 +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
Duncan P. N. Exon Smith 134cb5d30f BitcodeWriter: WorkList => Worklist, NFC
I have no idea how I chose two different spellings in the space of a
couple of weeks, but now I can't remember what to use where.  Choose
"Worklist".

llvm-svn: 266582
2016-04-18 01:24:58 +00:00
Duncan P. N. Exon Smith 5ab2be094e IR: Use an explicit map for debug info type uniquing
Rather than relying on the structural equivalence of DICompositeType to
merge type definitions, use an explicit map on the LLVMContext that
LLParser and BitcodeReader consult when constructing new nodes.
Each non-forward-declaration DICompositeType with a non-empty
'identifier:' field is stored/loaded from the type map, and the first
definiton will "win".

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

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

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

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

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

llvm-svn: 266549
2016-04-17 03:58:21 +00:00
Mehdi Amini 2d28f7aa07 ThinLTO: Make aliases explicit in the summary
To be able to work accurately on the reference graph when taking
decision about internalizing, promoting, renaming, etc. We need
to have the alias information explicit.

Differential Revision: http://reviews.llvm.org/D18836

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266517
2016-04-16 06:56:44 +00:00
Richard Smith 2db6f2e508 Update and fix LLVM_ENABLE_MODULES:
1) We need to add this flag prior to adding any other, in case the user has
specified a -fmodule-cache-path= flag in their custom CXXFLAGS. Such a flag
causes -Werror builds to fail, and thus all config checks fail, until we add
the corresponding -fmodules flag. The modules selfhost bot does this, for
instance.

2) Delete module maps that were putting .cpp files into modules.

3) Enable -fmodules-local-submodule-visibility, to get proper module
visibility rules applied across submodules of the same module. Disable
-fmodules for C builds, since that flag is not available there.

llvm-svn: 266502
2016-04-16 00:48:58 +00:00
Adrian Prantl 75819aedf6 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00
Mehdi Amini 03b42e41bf Remove every uses of getGlobalContext() in LLVM (but the C API)
At the same time, fixes InstructionsTest::CastInst unittest: yes
you can leave the IR in an invalid state and exit when you don't
destroy the context (like the global one), no longer now.

This is the first part of http://reviews.llvm.org/D19094

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266379
2016-04-14 21:59:01 +00:00
Mehdi Amini b5b289339b Revert "Make aliases explicit in the summary"
Inadvertently commited...

This reverts commit e618ec93786d99df2ddf280ad2d5e02f5516cecf.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266215
2016-04-13 17:20:07 +00:00
Mehdi Amini ce744a95fd Make aliases explicit in the summary
Summary:
To be able to work accurately on the reference graph when taking decision
about internalizing, promoting, renaming, etc. We need to have the alias
information explicit.

Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18836

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266214
2016-04-13 17:18:42 +00:00
George Burgess IV 278199f615 Add the allocsize attribute to LLVM.
`allocsize` is a function attribute that allows users to request that
LLVM treat arbitrary functions as allocation functions.

This patch makes LLVM accept the `allocsize` attribute, and makes
`@llvm.objectsize` recognize said attribute.

The review for this was split into two patches for ease of reviewing:
D18974 and D14933. As promised on the revisions, I'm landing both
patches as a single commit.

Differential Revision: http://reviews.llvm.org/D14933

llvm-svn: 266032
2016-04-12 01:05:35 +00:00
Teresa Johnson 6f6fa36244 [ThinLTO] BitcodeWriter still requires Analysis library
This should fix bot failure:
http://bb.pgr.jp/builders/i686-mingw32-RA-on-linux/builds/9873

The bitcode writer unfortunately still needs the Analysis library, as it
replaces old dependence on BFI etc with dependence on new
ModuleSummaryAnalysis pass.

llvm-svn: 265945
2016-04-11 14:59:07 +00:00
Teresa Johnson 2d5487cf44 [ThinLTO] Move summary computation from BitcodeWriter to new pass
Summary:
This is the first step in also serializing the index out to LLVM
assembly.

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

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

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

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

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

llvm-svn: 265941
2016-04-11 13:58:45 +00:00
Mehdi Amini f9e4576e08 Plumb the option to emit the `ModuleHash` in the bitcode through the bitcode writer APIs
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265907
2016-04-10 21:07:19 +00:00
Mehdi Amini 4a9a1816cb Rename parameter I to Index for WriteCombinedGlobalValueSummary() (NFC)
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265729
2016-04-07 21:49:31 +00:00
Dmitry Polukhin a1feff7024 [GCC] Attribute ifunc support in llvm
This patch add support for GCC attribute((ifunc("resolver"))) for
targets that use ELF as object file format. In general ifunc is a
special kind of function alias with type @gnu_indirect_function. Patch
for Clang http://reviews.llvm.org/D15524

Differential Revision: http://reviews.llvm.org/D15525

llvm-svn: 265667
2016-04-07 12:32:19 +00:00
JF Bastien 800f87a871 NFC: make AtomicOrdering an enum class
Summary:
In the context of http://wg21.link/lwg2445 C++ uses the concept of
'stronger' ordering but doesn't define it properly. This should be fixed
in C++17 barring a small question that's still open.

The code currently plays fast and loose with the AtomicOrdering
enum. Using an enum class is one step towards tightening things. I later
also want to tighten related enums, such as clang's
AtomicOrderingKind (which should be shared with LLVM as a 'C++ ABI'
enum).

This change touches a few lines of code which can be improved later, I'd
like to keep it as NFC for now as it's already quite complex. I have
related changes for clang.

As a follow-up I'll add:
  bool operator<(AtomicOrdering, AtomicOrdering) = delete;
  bool operator>(AtomicOrdering, AtomicOrdering) = delete;
  bool operator<=(AtomicOrdering, AtomicOrdering) = delete;
  bool operator>=(AtomicOrdering, AtomicOrdering) = delete;
This is separate so that clang and LLVM changes don't need to be in sync.

Reviewers: jyknight, reames

Subscribers: jyknight, llvm-commits

Differential Revision: http://reviews.llvm.org/D18775

llvm-svn: 265602
2016-04-06 21:19:33 +00:00
Duncan P. N. Exon Smith 1de3c7e790 IR: Introduce ConstantAggregate, NFC
Add a common parent class for ConstantArray, ConstantVector, and
ConstantStruct called ConstantAggregate.  These are the aggregate
subclasses of Constant that take operands.

This is mainly a cleanup, adding common `isa` target and removing
duplicated code.  However, it also simplifies caching which constants
point transitively at `GlobalValue` (a possible future direction).

llvm-svn: 265466
2016-04-05 21:10:45 +00:00
Dmitry Polukhin a3d5b0b218 [IFUNC] Use GlobalIndirectSymbol when aliases and ifuncs have something similar
Second part extracted from http://reviews.llvm.org/D15525

Use GlobalIndirectSymbol in all cases when aliases and ifuncs have
something in common.

Differential Revision: http://reviews.llvm.org/D18754

llvm-svn: 265382
2016-04-05 08:47:51 +00:00
Teresa Johnson fb7c764496 [ThinLTO] Refactor some common code into getGlobalValueInfo method (NFC)
Refactor common code that queries the ModuleSummaryIndex for a value's
GlobalValueInfo struct into getGlobalValueInfo helper methods, which
will also be used by D18763.

llvm-svn: 265370
2016-04-05 00:40:16 +00:00
Teresa Johnson 916495d894 [ThinLTO] Add option to dump value name to GUID mapping
Summary:
Useful for debugging since we lose this correlation after the permodule
summary/VST is read and until we later materialize source modules in the
function importer.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18555

llvm-svn: 265327
2016-04-04 18:52:58 +00:00
Mehdi Amini 8958c40430 Rename FunctionIndex into GlobalValueIndex to reflect the recent changes (NFC)
The index used to contain only Function, but now contains GlobalValue
in general.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265230
2016-04-02 17:29:47 +00:00
Duncan P. N. Exon Smith 520f8542ff Bitcode: Try to emit metadata in function blocks
Whenever metadata is only referenced by a single function, emit the
metadata just in that function block.  This should improve lazy-loading
by reducing the amount of metadata in the global block.

For now, this should catch all DILocations, and anything else that
happens to be referenced only by a single function.

It's also a first step toward a couple of possible future directions
(which this commit does *not* implement):

 1. Some debug info metadata is only referenced from compile units and
    individual functions.  If we can drop the link from the compile
    unit, this optimization will get more powerful.

 2. Any uniqued metadata that isn't referenced globally can in theory be
    emitted in every function block that references it (trading off
    bitcode size and full-parse time vs. lazy-load time).

Note: this assumes the new BitcodeReader error checking from r265223.
The metadata stored in function blocks gets purged after parsing each
function, which means unresolved forward references will get lost.
Since all the global metadata should have already been resolved by the
time we get to the function metadata blocks we just need to check for
that case.  (If for some reason we need to handle bitcode that fails the
checks in r265223, the fix is to store about-to-be-dropped unresolved
nodes in MetadataList::shrinkTo until they can be handled succesfully by
a future call to MetadataList::tryToResolveCycles.)

llvm-svn: 265226
2016-04-02 15:22:57 +00:00
Duncan P. N. Exon Smith 0b76b723f4 Fix doxygen comments from r265224, NFC
llvm-svn: 265225
2016-04-02 15:16:56 +00:00
Duncan P. N. Exon Smith 9342911f31 BitcodeWriter: Further unify function metadata, NFC
Further unify the handling of function-local metadata with global
metadata, by exposing the same interface in ValueEnumerator.  Both
contexts use the same accessors:

  - getMDStrings(): get the strings for this block.
  - getNonMDStrings(): get the non-strings for this block.

A future commit will start adding strings to the function-block.

llvm-svn: 265224
2016-04-02 15:09:42 +00:00
Duncan P. N. Exon Smith 8742de9b20 BitcodeReader: Check for unresolved function metadata
A follow-up commit will start using function metadata blocks more
heavily.  This commit adds some error checking to confirm that metadata
is fully resolved before (and after) materializing each function.

This is valid even when reading very old bitcode from before the
metadata/value split.  The global metadata block always came before the
function blocks.  However, in case somehow this causes a regression
(i.e., an old LLVM did produce such bitcode after all) I'm committing
separately.

llvm-svn: 265223
2016-04-02 14:55:01 +00:00
Mehdi Amini 1e5fddda3d Reverts r265219.
Unintentionally commited... time to call the day off!

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265221
2016-04-02 05:35:03 +00:00
Mehdi Amini 5921a3ae66 wip
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265219
2016-04-02 05:34:14 +00:00
Mehdi Amini ad5741b075 Create a typedef GlobalValue::GUID for uint64_t and RAUW (NFC)
Summary: This should make the code more readable, especially all the map declarations.

Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18721

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265215
2016-04-02 05:07:53 +00:00
Manman Ren 9bfd0d03e9 Swift Calling Convention: add swifterror attribute.
A ``swifterror`` attribute can be applied to a function parameter or an
AllocaInst.

This commit does not include any target-specific change. The target-specific
optimization will come as a follow-up patch.

Differential Revision: http://reviews.llvm.org/D18092

llvm-svn: 265189
2016-04-01 21:41:15 +00:00
Mehdi Amini d7ad221c16 Add a module Hash in the bitcode and the combined index, implementing a kind of "build-id"
This is intended to be used for ThinLTO incremental build.

Differential Revision: http://reviews.llvm.org/D18213

This is a recommit of r265095 after fixing the Windows issues.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265111
2016-04-01 05:33:11 +00:00
Mehdi Amini 85fb9e058e Revert "Add support for computing SHA1 in LLVM"
This reverts commit r265096, r265095, and r265094.
Windows build is broken, and the validation does not pass.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265102
2016-04-01 03:03:21 +00:00
Mehdi Amini 4c2ed3337d Add a module Hash in the bitcode and the combined index, implementing a kind of "build-id"
This is intended to be used for ThinLTO incremental build.

Differential Revision: http://reviews.llvm.org/D18213

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265095
2016-04-01 01:30:06 +00:00
Duncan P. N. Exon Smith 7457ecbebe BitcodeReader: Fix weird whitespace, NFC
llvm-svn: 264822
2016-03-30 04:21:52 +00:00
Teresa Johnson b703c77b03 [ThinLTO] Remove post-pass metadata linking support
Since we have moved to a model where functions are imported in bulk from
each source module after making summary-based importing decisions, there
is no longer a need to link metadata as a postpass, and all users have
been removed.

This essentially reverts r255909 and follow-on fixes.

llvm-svn: 264763
2016-03-29 18:24:19 +00:00
Manman Ren f46262e0b7 Swift Calling Convention: add swiftself attribute.
Differential Revision: http://reviews.llvm.org/D17866

llvm-svn: 264754
2016-03-29 17:37:21 +00:00
Duncan P. N. Exon Smith bb7ce3b850 BitcodeReader: Allow METADATA_STRINGS to only have !""
Support parsing a METADATA_STRINGS record that only has a single piece
of metadata, !"".  Fixes a corner case in r264551.

llvm-svn: 264699
2016-03-29 05:25:17 +00:00
Duncan P. N. Exon Smith 544e4f97b3 BitcodeWriter: Replace dead code with an assertion, NFC
The caller of ValueEnumerator::EnumerateOperandType never sends in
metadata.  Assert that, and remove the unnecessary logic.

llvm-svn: 264558
2016-03-28 00:03:12 +00:00
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
Duncan P. N. Exon Smith 456c9968e5 Support: Implement StreamingMemoryObject::getPointer
The implementation is fairly obvious.  This is preparation for using
some blobs in bitcode.

For clarity (and perhaps future-proofing?), I moved the call to
JumpToBit in BitstreamCursor::readRecord ahead of calling
MemoryObject::getPointer, since JumpToBit can theoretically (a) read
bytes, which (b) invalidates the blob pointer.

This isn't strictly necessary the two memory objects we have:

  - The return of RawMemoryObject::getPointer is valid until the memory
    object is destroyed.

  - StreamingMemoryObject::getPointer is valid until the next chunk is
    read from the stream.  Since the JumpToBit call is only going ahead
    to a word boundary, we'll never load another chunk.

However, reordering makes it clear by inspection that the blob returned
by BitstreamCursor::readRecord will be valid.

I added some tests for StreamingMemoryObject::getPointer and
BitstreamCursor::readRecord.

llvm-svn: 264549
2016-03-27 23:00:59 +00:00
Duncan P. N. Exon Smith d3be62ddf2 Bitcode: Add SimpleBitstreamCursor::getPointerToByte, etc.
Add API to SimpleBitstreamCursor to allow users to translate between
byte addresses and pointers.

  - jumpToPointer: move the bit position to a particular pointer.
  - getPointerToByte: get the pointer for a particular byte.
  - getPointerToBit: get the pointer for the byte of the current bit.
  - getCurrentByteNo: convenience function for assertions and tests.

Mainly adds unit tests (getPointerToBit/Byte already has a use), but
also preparation for eventually using jumpToPointer.

llvm-svn: 264546
2016-03-27 22:45:25 +00:00
Duncan P. N. Exon Smith d766d136ce Bitcode: Split out SimpleBitstreamCursor
Split out SimpleBitstreamCursor from BitstreamCursor, which is a
lower-level cursor with no knowledge of bitcode blocks, abbreviations,
or records.  It just knows how to read bits and navigate the stream.

This is mainly organizational, to separate the API for manipulating raw
bits from that for bitcode concepts like Record and Block.

llvm-svn: 264545
2016-03-27 22:40:55 +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 bdde9e1f21 Bitcode: Use std::stable_partition for reproducible builds
Caught by inspection while working on partitioning metadata.  It's nice
to produce the same bitcode if you run the compiler twice.

llvm-svn: 264381
2016-03-25 02:20:28 +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 efe16c8eb4 IR: Stop upgrading !llvm.loop attachments via MDString
Remove logic to upgrade !llvm.loop by changing the MDString tag
directly.  This old logic would check (and change) arbitrary strings
that had nothing to do with loop metadata.  Instead, check !llvm.loop
attachments directly, and change which strings get attached.

Rather than updating the assembly-based upgrade, drop it entirely.  It
has been quite a while since we supported upgrading textual IR.

llvm-svn: 264373
2016-03-25 00:56:13 +00:00