We used to report PLT traces as invalid (mismatching disassembled
function contents) because PLT functions are marked as pseudo and
ignored, thus missing CFG. However, such traces are not mismatching
the function contents. Accept them without attaching the profile.
Test Plan: updated callcont-fallthru.s
Traces are triplets of branch source, target, and fall-through end (next
branch).
Traces simplify differentiation of fall-throughs into local- and
external-origin, which improves performance over profile with
undifferentiated fall-throughs by eliminating profile discontinuity in
call to continuation fall-throughs. This makes it possible to avoid
converting return profile into call to continuation profile which may
introduce statistical biases.
The existing format makes provisions for local- (F) and external- (f)
origin fall-throughs, but the profile producer needs to know function
boundaries. BOLT has that information readily available, so providing
the origin branch of a fall-through is a functional replacement of the
fall-through kind (f or F). This also has an effect of combining
branches and fall-throughs into a single record.
As traces subsume other pre-aggregated profile kinds, BOLT may drop
support for them soon. Users of pre-aggregated profile format are
advised to migrate to the trace format.
Test Plan: Updated callcont-fallthru.s
Disambiguate local functions using the containing file symbol in BAT
mode. Make local function naming consistent across BAT fdata and YAML
profiles.
Test Plan: updated register-fragments-bolt-symbols.s
This is an ongoing series of commits that are reformatting our
Python code. This catches the last of the python files to
reformat. Since they where so few I bunched them together.
Reformatting is done with `black`.
If you end up having problems merging this commit because you
have made changes to a python file, the best way to handle that
is to run git checkout --ours <yourfile> and then reformat it
with black.
If you run into any problems, post to discourse about it and
we will try to help.
RFC Thread below:
https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style
Reviewed By: jhenderson, #libc, Mordante, sivachandra
Differential Revision: https://reviews.llvm.org/D150784
No-LBR mode wasn't tested and slipped when mayHaveProfileData was added for
Lite mode. This enables processing of profiles collected without LBR and
converted with `perf2bolt -nl` option.
Test Plan:
bin/llvm-lit -a tools/bolt/test/X86/nolbr.s
https://github.com/rafaelauler/bolt-tests/pull/20
Reviewed By: #bolt, rafauler
Differential Revision: https://reviews.llvm.org/D140256
Summary:
Import the test. The assembly input has three functions with associated fdata.
The old link_fdata.sh script only replaces the symbol names with symbol values,
whereas fdata format expects to have symbol offsets against the anchor symbol.
Introduce the link_fdata.py script which is able to parse the input and produce
either an offset or an absolute symbol value.
(cherry picked from FBD32256351)
