[test] Remove duplicate -sample-profile tests

When -passes=sample-profile is tested, -sample-profile is redundant.

[SampleFDO] Add use-sample-profile function attribute.

When sampleFDO is enabled, people may expect they can use
-fno-profile-sample-use to opt-out using sample profile for a certain file.
That coul

[SampleFDO] Add use-sample-profile function attribute.

When sampleFDO is enabled, people may expect they can use
-fno-profile-sample-use to opt-out using sample profile for a certain file.
That could be either for debugging purpose or for performance tuning purpose.
However, when thinlto is enabled, if a function in file A compiled with
-fno-profile-sample-use is imported to another file B compiled with
-fprofile-sample-use, the inlined copy of the function in file B may still
get its profile annotated.

The inconsistency may even introduce profile unused warning because if the
target is not compiled with explicit debug information flag, the function
in file A won't have its debug information enabled (debug information will
be enabled implicitly only when -fprofile-sample-use is used). After it is
imported into file B which is compiled with -fprofile-sample-use, profile
annotation for the outline copy of the function will fail because the
function has no debug information, and that will trigger profile unused
warning.

We add a new attribute use-sample-profile to control whether a function
will use its sample profile no matter for its outline or inline copies.
That will make the behavior of -fno-profile-sample-use consistent.

Differential Revision: https://reviews.llvm.org/D79959

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Revert "Temporarily Revert "Add basic loop fusion pass.""

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

[PM] Port the Sample FDO to new PM (part-2)

llvm-svn: 271072

[llvm-profdata] Add check for text profile formats and improve error reporting (2nd try)

Summary:
This change addresses two possible instances of user error / confusion when
merging sampled profile

[llvm-profdata] Add check for text profile formats and improve error reporting (2nd try)

Summary:
This change addresses two possible instances of user error / confusion when
merging sampled profile data.

Previously any input that didn't match the raw or processed instrumented format
would automatically be interpreted as instrumented profile text format data.
No error would be reported during the merge.

Example:
If foo-sampled.profdata and bar-sampled.profdata are binary sampled profiles:

Old behavior:
$ llvm-profdata merge foo-sampled.profdata bar-sampled.profdata -output foobar-sampled.profdata
$ llvm-profdata show -sample foobar-sampled.profdata
error: foobar-sampled.profdata:1: Expected 'mangled_name:NUM:NUM', found lprofi

This change adds basic checks for valid input data when assuming text input.
It also makes error messages related to file format validity more specific about
the assumbed profile data type.

New behavior:
$ llvm-profdata merge foo-sampled.profdata bar-sampled.profdata -o foobar-sampled.profdata
error: foo.profdata: Unrecognized instrumentation profile encoding format
Perhaps you forgot to use the -sample option?

Reviewers: bogner, davidxl, dnovillo

Subscribers: davidxl, llvm-commits

Differential Revision: http://reviews.llvm.org/D14558

llvm-svn: 253009

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llvm/test/Transforms/SampleProfile/syntax.ll: Relax MISSING-FILE not to
check locale-aware message catalog.

llvm-svn: 220934

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 enc

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

llvm-svn: 220915

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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

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.

llvm-svn: 220386

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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.

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

llvm-svn: 204142

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llvm/test/Transforms/SampleProfile/syntax.ll: Suppress checking the message catalog in ENOENT. It is locale-dependent on Windows.

llvm-svn: 203997

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 Diagnost

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

llvm-svn: 203976

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Use discriminator information in sample profiles.

Summary:
When the sample profiles include discriminator information,
use the discriminator values to distinguish instruction weights
in different ba

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

llvm-svn: 203508

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llvm/test/Transforms/SampleProfile/syntax.ll: Eliminate locale-sensitive message check.

llvm-svn: 199000

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 r

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

llvm-svn: 198973

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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 Deha

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.

llvm-svn: 198972

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llvm/test/Transforms/SampleProfile/syntax.ll: Relax an expression, not to check locale-dependent message.

llvm-svn: 196195

Add tests for profile sample file parsing.

The profile file parser needed some tests for its parsing actions.
This adds tests for each of the error messages emitted by the parser.

llvm-svn: 196106