Commit Graph

52 Commits

Author SHA1 Message Date
Alexander Kornienko
cf0db29df2 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 15:57:42 +00:00
Eric Christopher
933d2bd391 Fix "the the" in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240112 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 01:53:21 +00:00
Diego Novillo
0e0929ed98 Add function entry counts from sample profiles.
This patch uses the new function profile metadata "function_entry_count"
to annotate entry counts from sample profiles.

In a sampling profile, the total samples collected at the function entry
are an approximation for the number of times that function was invoked.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 17:04:29 +00:00
Duncan P. N. Exon Smith
e56023a059 IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one.  It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs.  YMMV of
course.

Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py.  I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three.  It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).

Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236120 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 16:38:44 +00:00
Duncan P. N. Exon Smith
7f892716df DebugInfo: Drop rest of DIDescriptor subclasses
Delete the remaining subclasses of (the already deleted) `DIDescriptor`.
Part of PR23080.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235404 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 18:44:06 +00:00
Duncan P. N. Exon Smith
125e3d3959 DebugInfo: Gut DISubprogram and DILexicalBlock*
Gut the `DIDescriptor` wrappers around `MDLocalScope` subclasses.  Note
that `DILexicalBlock` wraps `MDLexicalBlockBase`, not `MDLexicalBlock`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234850 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 03:40:37 +00:00
Duncan P. N. Exon Smith
d59e30dfb7 DebugInfo: Gut DILocation
This is along the same lines as r234832, but for `DILocation`.  Clean
out all accessors from `DILocation`.  Any callers should be using
`MDLocation` directly (e.g., via `operator->()`).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234835 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 01:35:55 +00:00
Duncan P. N. Exon Smith
573ca050d2 Transforms: Stop using DIDescriptor::is*() and auto-casting
Same as r234255, but for lib/Analysis and lib/Transforms.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234257 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 23:27:00 +00:00
Duncan P. N. Exon Smith
f175439a2b Transforms: Use the new DebugLoc API, NFC
Update lib/Analysis and lib/Transforms to use the new `DebugLoc` API.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233587 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-30 19:49:49 +00:00
Duncan P. N. Exon Smith
67934e4b41 SampleProfile: Check for missing debug locations
Don't use `DebugLoc` accessors if we're pointing at null, which will be
a problem after a WIP patch to make the `DIDescriptor` accessors more
strict.  Caught by Frontend/profile-sample-use-loc-tracking.c (in
clang).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232792 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-20 00:56:55 +00:00
Chandler Carruth
de5df29556 [PM] Split the LoopInfo object apart from the legacy pass, creating
a LoopInfoWrapperPass to wire the object up to the legacy pass manager.

This switches all the clients of LoopInfo over and paves the way to port
LoopInfo to the new pass manager. No functionality change is intended
with this iteration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226373 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-17 14:16:18 +00:00
David Blaikie
5401ba7099 Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 07:49:26 +00:00
Diego Novillo
2b6bd7aaf5 Use ErrorOr for the ::create factory on instrumented and sample profilers.
Summary:
As discussed in
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20141027/242445.html,
the creation of reader and writer instances is better done using
ErrorOr. There are no functional changes, but several callers needed to
be adjusted.

Reviewers: bogner

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6076

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221120 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-03 00:51:45 +00:00
Diego Novillo
496bd0b8a5 Fix Twine corruption problem with diagnostics.
This fixes the autobuilders I broke with a recent patch. Thanks echristo
and dblaikie for beating me with a clue stick.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220918 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-30 18:48:41 +00:00
Diego Novillo
e75c2b3e54 Add profile writing capabilities for sampling profiles.
Summary:
This patch finishes up support for handling sampling profiles in both
text and binary formats. The new binary format uses uleb128 encoding to
represent numeric values. This makes profiles files about 25% smaller.

The profile writer class can write profiles in the existing text and the
new binary format. In subsequent patches, I will add the capability to
read (and perhaps write) profiles in the gcov format used by GCC.

Additionally, I will be adding support in llvm-profdata to manipulate
sampling profiles.

There was a bit of refactoring needed to separate some code that was in
the reader files, but is actually common to both the reader and writer.

The new test checks that reading the same profile encoded as text or
raw, produces the same results.

Reviewers: bogner, dexonsmith

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6000

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220915 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-30 18:00:06 +00:00
Timur Iskhodzhanov
da45b2bdbd Make getDISubprogram(const Function *F) available in LLVM
Reviewed at http://reviews.llvm.org/D5950

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220536 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-23 23:46:28 +00:00
Diego Novillo
0b70f777bb Shorten auto iterators for function basic blocks.
Use consistent naming for basic block instances.

No functional changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220404 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 18:39:50 +00:00
Diego Novillo
e64e141886 Use auto iteration in lib/Transforms/Scalar/SampleProfile.cpp. No functional changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220394 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 16:51:50 +00:00
Diego Novillo
79ca2c234d Change error to warning when a profile cannot be found.
When the profile for a function cannot be applied, we use to emit an
error. This seems extreme. The compiler can continue, it's just that the
optimization opportunities won't include profile information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220386 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 13:36:35 +00:00
Diego Novillo
418d0cf1c1 Support using sample profiles with partial debug info.
Summary:
When using a profile, we used to require the use -gmlt so that we could
get access to the line locations. This is used to match line numbers in
the input profile to the line numbers in the function's IR.

But this is actually not necessary. The driver can provide source
location tracking without the emission of debug information. In these
cases, the annotation 'llvm.dbg.cu' is missing from the IR, but the
actual line location annotations are still present.

This patch adds a new way of looking for the start of the current
function. Instead of looking through the compile units in llvm.dbg.cu,
we can walk up the scope for the first instruction in the function with
a debug loc. If that describes the function, we use it. Otherwise, we
keep looking until we find one.

If no such instruction is found, we then give up and produce an error.

Reviewers: echristo, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5887

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220382 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 12:59:00 +00:00
NAKAMURA Takumi
589d2fc893 SampleProfile.cpp: Prune a stray \param added in r217437. [-Wdocumentation]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217465 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-09 22:44:30 +00:00
Diego Novillo
40c949a1b4 Re-factor sample profile reader into lib/ProfileData.
Summary:
This patch moves the profile reading logic out of the Sample Profile
transformation into a generic profile reader facility in
lib/ProfileData.

The intent is to use this new reader to implement a sample profile
reader/writer that can be used to convert sample profiles from external
sources into LLVM.

This first patch introduces no functional changes. It moves the profile
reading code from lib/Transforms/SampleProfile.cpp into
lib/ProfileData/SampleProfReader.cpp.

In subsequent patches I will:

- Add a bitcode format for sample profiles to allow for more efficient
  encoding of the profile.
- Add a writer for both text and bitcode format profiles.
- Add a 'convert' command to llvm-profdata to be able to convert between
  the two (and serve as entry point for other sample profile formats).

Reviewers: bogner, echristo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5250

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217437 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-09 12:40:50 +00:00
Rafael Espindola
9aa0b5e11e Remove some calls to std::move.
Instead of moving out the data in a ErrorOr<std::unique_ptr<Foo>>, get
a reference to it.

Thanks to David Blaikie for the suggestion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214516 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-01 14:31:55 +00:00
Duncan P. N. Exon Smith
facdfc6781 Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."
This reverts commit r213474 (and r213475), which causes a miscompile on
a stage2 LTO build.  I'll reply on the list in a moment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213562 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-21 17:06:51 +00:00
Manuel Jacob
a4697dad19 [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges.
Summary: This patch introduces two new iterator ranges and updates existing code to use it.  No functional change intended.

Test Plan: All tests (make check-all) still pass.

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4481

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213474 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-20 09:10:11 +00:00
Rafael Espindola
7cba2a973f Update the MemoryBuffer API to use ErrorOr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212405 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-06 17:43:13 +00:00
Rafael Espindola
4e2b922131 Remove 'using std::errro_code' from lib.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210871 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 02:24:39 +00:00
Rafael Espindola
5c792faa0e Don't use 'using std::error_code' in include/llvm.
This should make sure that most new uses use the std prefix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210835 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 21:46:39 +00:00
Craig Topper
8d7221ccf5 [C++] Use 'nullptr'. Transforms edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207196 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 05:29:35 +00:00
Chandler Carruth
7962dbdc65 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206844 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:55:47 +00:00
Alp Toker
46d36be2eb Fix some doc and comment typos
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205899 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-09 14:47:27 +00:00
Diego Novillo
c605296342 Tolerate unmangled names in sample profiles.
Summary:
The compiler does not always generate linkage names. If a function
has been inlined and its body elided, its linkage name may not be
generated.

When the binary executes, the profiler will use its unmangled name
when attributing samples. This results in unmangled names in the
input profile.

We are currently failing hard when this happens. However, in this case
all that happens is that we fail to attribute samples to the inlined
function. While this means fewer optimization opportunities, it should
not cause a compilation failure.

This patch accepts all valid function names, regardless of whether
they were mangled or not.

Reviewers: chandlerc

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D3087

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204142 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-18 12:03:12 +00:00
David Blaikie
72ca6ef7f8 Remove named Twine.
While technically correct, we generally disallow any instance of named
Twines due to their subtlety.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204016 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-16 01:36:18 +00:00
NAKAMURA Takumi
5d45272acc SampleProfile.cpp: Fix take #2. The issue was abuse of StringRef here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203996 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-15 01:56:17 +00:00
NAKAMURA Takumi
ba3fc12d80 SampleProfile.cpp: Quick fix to r203976 about abuse of Twine. The life of Twine was too short.
FIXME: DiagnosticInfoSampleProfile should not hold Twine&.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-15 00:10:12 +00:00
Diego Novillo
68c1cb444f Re-format SampleProfile.cpp with clang-format. No functional changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203977 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-14 22:07:18 +00:00
Diego Novillo
3f7c2f31ff Use DiagnosticInfo facility.
Summary:
The sample profiler pass emits several error messages. Instead of
just aborting the compiler with report_fatal_error, we can emit
better messages using DiagnosticInfo.

This adds a new sub-class of DiagnosticInfo to handle the sample
profiler.

Reviewers: chandlerc, qcolombet

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D3086

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203976 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-14 21:58:59 +00:00
Diego Novillo
87393cfd6b Use discriminator information in sample profiles.
Summary:
When the sample profiles include discriminator information,
use the discriminator values to distinguish instruction weights
in different basic blocks.

This modifies the BodySamples mapping to map <line, discriminator> pairs
to weights. Instructions on the same line but different blocks, will
use different discriminator values. This, in turn, means that the blocks
may have different weights.

Other changes in this patch:

- Add tests for positive values of line offset, discriminator and samples.
- Change data types from uint32_t to unsigned and int and do additional
  validation.

Reviewers: chandlerc

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2857

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203508 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-10 22:41:28 +00:00
Ahmed Charles
f4ccd11075 Replace OwningPtr<T> with std::unique_ptr<T>.
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203083 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-06 05:51:42 +00:00
Chandler Carruth
f4ec8bfaec [Layering] Move DebugInfo.h into the IR library where its implementation
already lives.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203046 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-06 00:46:21 +00:00
Craig Topper
7b62be28cb [C++11] Add 'override' keyword to virtual methods that override their base class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202953 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-05 09:10:37 +00:00
Chandler Carruth
876ac60880 [Modules] Move InstIterator out of the Support library, where it had no
business.

This header includes Function and BasicBlock and directly uses the
interfaces of both classes. It has to do with the IR, it even has that
in the name. =] Put it in the library it belongs to.

This is one step toward making LLVM's Support library survive a C++
modules bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202814 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 10:30:26 +00:00
Logan Chien
5e89e33e78 Include <cctype> for isdigit().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201930 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-22 06:34:10 +00:00
Chandler Carruth
7f2eff792a [PM] Split DominatorTree into a concrete analysis result object which
can be used by both the new pass manager and the old.

This removes it from any of the virtual mess of the pass interfaces and
lets it derive cleanly from the DominatorTreeBase<> template. In turn,
tons of boilerplate interface can be nuked and it turns into a very
straightforward extension of the base DominatorTree interface.

The old analysis pass is now a simple wrapper. The names and style of
this split should match the split between CallGraph and
CallGraphWrapperPass. All of the users of DominatorTree have been
updated to match using many of the same tricks as with CallGraph. The
goal is that the common type remains the resulting DominatorTree rather
than the pass. This will make subsequent work toward the new pass
manager significantly easier.

Also in numerous places things became cleaner because I switched from
re-running the pass (!!! mid way through some other passes run!!!) to
directly recomputing the domtree.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199104 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-13 13:07:17 +00:00
Chandler Carruth
56e1394c88 [cleanup] Move the Dominators.h and Verifier.h headers into the IR
directory. These passes are already defined in the IR library, and it
doesn't make any sense to have the headers in Analysis.

Long term, I think there is going to be a much better way to divide
these matters. The dominators code should be fully separated into the
abstract graph algorithm and have that put in Support where it becomes
obvious that evn Clang's CFGBlock's can use it. Then the verifier can
manually construct dominance information from the Support-driven
interface while the Analysis library can provide a pass which both
caches, reconstructs, and supports a nice update API.

But those are very long term, and so I don't want to leave the really
confusing structure until that day arrives.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199082 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-13 09:26:24 +00:00
Chandler Carruth
9f20a4c6ce Re-sort #include lines again, prior to moving headers around.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199080 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-13 08:04:33 +00:00
Diego Novillo
4b2b2da9c7 Extend and simplify the sample profile input file.
1- Use the line_iterator class to read profile files.

2- Allow comments in profile file. Lines starting with '#'
   are completely ignored while reading the profile.

3- Add parsing support for discriminators and indirect call samples.

   Our external profiler can emit more profile information that we are
   currently not handling. This patch does not add new functionality to
   support this information, but it allows profile files to provide it.

   I will add actual support later on (for at least one of these
   features, I need support for DWARF discriminators in Clang).

   A sample line may contain the following additional information:

   Discriminator. This is used if the sampled program was compiled with
   DWARF discriminator support
   (http://wiki.dwarfstd.org/index.php?title=Path_Discriminators). This
   is currently only emitted by GCC and we just ignore it.

   Potential call targets and samples. If present, this line contains a
   call instruction. This models both direct and indirect calls. Each
   called target is listed together with the number of samples. For
   example,

                    130: 7  foo:3  bar:2  baz:7

   The above means that at relative line offset 130 there is a call
   instruction that calls one of foo(), bar() and baz(). With baz()
   being the relatively more frequent call target.

   Differential Revision: http://llvm-reviews.chandlerc.com/D2355

4- Simplify format of profile input file.

   This implements earlier suggestions to simplify the format of the
   sample profile file. The symbol table is not necessary and function
   profiles do not need to know the number of samples in advance.

   Differential Revision: http://llvm-reviews.chandlerc.com/D2419

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198973 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-10 23:23:51 +00:00
Diego Novillo
0de8cecb84 Propagation of profile samples through the CFG.
This adds a propagation heuristic to convert instruction samples
into branch weights. It implements a similar heuristic to the one
implemented by Dehao Chen on GCC.

The propagation proceeds in 3 phases:

1- Assignment of block weights. All the basic blocks in the function
   are initial assigned the same weight as their most frequently
   executed instruction.

2- Creation of equivalence classes. Since samples may be missing from
   blocks, we can fill in the gaps by setting the weights of all the
   blocks in the same equivalence class to the same weight. To compute
   the concept of equivalence, we use dominance and loop information.
   Two blocks B1 and B2 are in the same equivalence class if B1
   dominates B2, B2 post-dominates B1 and both are in the same loop.

3- Propagation of block weights into edges. This uses a simple
   propagation heuristic. The following rules are applied to every
   block B in the CFG:

   - If B has a single predecessor/successor, then the weight
     of that edge is the weight of the block.

   - If all the edges are known except one, and the weight of the
     block is already known, the weight of the unknown edge will
     be the weight of the block minus the sum of all the known
     edges. If the sum of all the known edges is larger than B's weight,
     we set the unknown edge weight to zero.

   - If there is a self-referential edge, and the weight of the block is
     known, the weight for that edge is set to the weight of the block
     minus the weight of the other incoming edges to that block (if
     known).

Since this propagation is not guaranteed to finalize for every CFG, we
only allow it to proceed for a limited number of iterations (controlled
by -sample-profile-max-propagate-iterations). It currently uses the same
GCC default of 100.

Before propagation starts, the pass builds (for each block) a list of
unique predecessors and successors. This is necessary to handle
identical edges in multiway branches. Since we visit all blocks and all
edges of the CFG, it is cleaner to build these lists once at the start
of the pass.

Finally, the patch fixes the computation of relative line locations.
The profiler emits lines relative to the function header. To discover
it, we traverse the compilation unit looking for the subprogram
corresponding to the function. The line number of that subprogram is the
line where the function begins. That becomes line zero for all the
relative locations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198972 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-10 23:23:46 +00:00
Chandler Carruth
974a445bd9 Re-sort all of the includes with ./utils/sort_includes.py so that
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.

Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198685 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 11:48:04 +00:00
Diego Novillo
d0d8d6462a Refactor some code in SampleProfile.cpp
I'm adding new functionality in the sample profiler. This will
require more data to be kept around for each function, so I moved
the structure SampleProfile that we keep for each function into
a separate class.

There are no functional changes in this patch. It simply provides
a new home where to place all the new data that I need to propagate
weights through edges.

There are some other name and minor edits throughout.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195780 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-26 20:37:33 +00:00