Binary encoded profiles used to encode all function names inline at
every reference. This is clearly suboptimal in terms of space. This
patch fixes this by adding a name table to the header of the file.
llvm-svn: 250241
With this patch we can now read and write inline stacks in sample
profiles to the binary encoded profiles.
In a subsequent patch, I will add a string table to the binary encoding.
Right now function names are emitted as strings every time we find them.
This is too bloated and will produce large files in applications with
lots of inlining.
llvm-svn: 249861
This fixes memory allocation problems by making the merge operation keep
the profile readers around until the merged profile has been emitted.
This is needed to prevent the inlined function names to disappear from
the function profiles. Since all the names are kept as references, once
the reader disappears, the names are also deallocated.
Additionally, XFAIL on big-endian architectures. The test case uses a
gcov file generated on a little-endian system.
llvm-svn: 249724
This patch adds support for reading sample profiles with inline stacks.
Inline stacks in a profile are generated when the sampled binary has
samples in inlined functions.
For instance, if main() calls foo() and foo() calls bar(), and bar() is
inlined into foo() and foo() inlined into main(), the profile may look
something like:
main total:364084 head:0
[ ... ]
2.3: _Z3fool total:243786
1: 60149
1.2: 38568
1.4: 46511
1.7: _Z3bari total:98558
1.1: 52672
1.2: 45886
At line 2, discriminator 3, main() calls foo(). In turn, foo() calls
bar() at line 1, discriminator 7.
In the textual format, this stacking of inline calls is represented
with indentation.
With this change, LLVM can now read sample profile files generated by
the create_gcov tool from https://github.com/google/autofdo.
llvm-svn: 249644
Given the work we are doing on ThinLTO, we will never need to support
module groups and working sets in GCC's implementation of LIPO. These
are currently dead code, and will continue to be so.
llvm-svn: 249351
This adds enough machinery to support reading simple GCC AutoFDO
profiles. It now supports reading flat profiles (no function calls).
Subsequent patches will add support for:
- Inlined calls (in particular, the inline call stack is not traversed
to accumulate samples).
- Working sets and modules. These are used mostly for GCC's LIPO
optimizations, so they're not needed in LLVM atm. I'm not sure that
we will ever need them. For now, I've if0'd around the calls.
The patch also adds support in GCOV.h for gcov version V704 (generated
by GCC's profile conversion tool).
llvm-svn: 247874
Summary:
This patch extends the 'show' and 'merge' commands in llvm-profdata to handle
sample PGO formats. Using the 'merge' command it is now possible to convert
one sample PGO format to another.
The only format that is currently not working is 'gcc'. I still need to
implement support for it in lib/ProfileData.
The changes in the sample profile support classes are needed for the
merge operation.
Reviewers: bogner
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6065
llvm-svn: 221032
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
It isn't always useful to skip blank lines, as evidenced by the
somewhat awkward use of line_iterator in llvm-cov. This adds a knob to
control whether or not to skip blanks.
llvm-svn: 217960
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
llvm-svn: 217437
Diego Novillo