Debug info correlation is an option in InstrProfiling pass, which is used by
both IR instrumentation and front-end instrumentation. So, Clang coverage can
also benefits the binary size saving from it.
Reviewed By: ellis
Differential Revision: https://reviews.llvm.org/D157913
When using debug info correlation, value profiling needs to be switched off.
So, we are only merging counter sections. In that case the existance of data
section is just used to provide an extra check in case of corrupted profile.
This patch performs counter merging by iterating the counter section by counter
size and add them together.
Reviewed By: ellis, MaskRay
Differential Revision: https://reviews.llvm.org/D157632
Original patch: D157632.
Fixed the issue when data is 0 by relaxing the condition.
Reviewed By: ellis
Differential Revision: https://reviews.llvm.org/D159000
Emit warnings when `InstrProfCorrelator` finds problems with debug info for lightweight instrumentation profile correlation. To prevent excessive printing, only emit the first 5 warnings.
In addition, remove a diagnostic about missing debug info in `InstrProfiling.cpp`. Some compiler-generated functions, e.g., `__clang_call_terminate`, does not emit debug info and will fail a build if `-Werror` is used. This warning is not actionable by the user and I have not seen non-compiler-generated functions fail this test.
Reviewed By: smeenai
Differential Revision: https://reviews.llvm.org/D156006
When using debug info correlation, value profiling needs to be switched off.
So, we are only merging counter sections. In that case the existance of data
section is just used to provide an extra check in case of corrupted profile.
This patch performs counter merging by iterating the counter section by counter
size and add them together.
Reviewed By: ellis, MaskRay
Differential Revision: https://reviews.llvm.org/D157632
The `llvm-profdata show` command is not sufficient to check that two
profiles are identical because it doesn't show the counter values. Add
the flags `--all-functions --counts` so that counter values are checked.
This was changed in https://reviews.llvm.org/D135929 but I failed to
remember that counter values were not printed by default.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D157665
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
This adds the --check-binary-id flag that makes sure that an object file
is available for every binary ID mentioned in the given profile. This
should help make the tool more robust in CI environments where it's
expected that coverage mappings should be available for every object
contributing to the profile.
Reviewed By: gulfem
Differential Revision: https://reviews.llvm.org/D144308
Since binary ID lookup makes CLI object arguments optional, it should be
possible to pass a list of source files without a binary. Unfortunately,
the current syntax will always interpret the first source file as a
binary. This change adds a `-sources` option to cause all later
positional arguments to be considered sources.
Reviewed By: gulfem
Differential Revision: https://reviews.llvm.org/D144207
Depends on https://reviews.llvm.org/D142861.
Alternative to https://reviews.llvm.org/D137601.
xxHash is much faster than djbHash. This makes a simple Rust test case with a large constant string 10% faster to compile.
Previous attempts at changing this hash function (e.g. https://reviews.llvm.org/D97396) had to be reverted due to breaking tests that depended on iteration order.
No additional tests fail with this patch compared to `main` when running `check-all` with `-DLLVM_ENABLE_PROJECTS="all"` (on a Linux host), so I hope I found everything that needs to be changed.
Differential Revision: https://reviews.llvm.org/D142862
The tests contain a redundant condition in the else if branch that can
be simplified with fb13dcf343.
Update the condition used to prevent it from getting removed.
Alive2 proof for check removal:
https://alive2.llvm.org/ce/z/iFBnsy
This patch adds support for including binary ids in an indexed profile.
It adds a new field into the header that points to the offset of the
binary id section. The binary id section consists of a size of the
section, and a list of binary ids (if they are present) that consist
of two parts: length and data.
This patch guarantees that indexed profile is backwards compatible
after adding binary ids.
Differential Revision: https://reviews.llvm.org/D135929
This caused lld on mac to assert when building instrumented clang (or
instrumented code in general). See comment on the code review for
reproducer.
> In many cases, we can use an alias to avoid a symbolic relocations,
> instead of using the public, interposable symbol. When the instrumented
> function is in a COMDAT, we can use a hidden alias, and still avoid
> references to discarded sections.
>
> New compiler-rt tests are Linux only for now.
>
> Previous versions of this patch allowed the compiler to name the
> generated alias, but that would only be valid when the functions were
> local. Since the alias may be used across TUs we use a more
> deterministic naming convention, and add a `.local` suffix to the alias
> name just as we do for relative vtables aliases.
>
> Reviewed By: phosek
>
> Differential Revision: https://reviews.llvm.org/D137982
This reverts commit c42e50fede.
In many cases, we can use an alias to avoid a symbolic relocations,
instead of using the public, interposable symbol. When the instrumented
function is in a COMDAT, we can use a hidden alias, and still avoid
references to discarded sections.
New compiler-rt tests are Linux only for now.
Previous versions of this patch allowed the compiler to name the
generated alias, but that would only be valid when the functions were
local. Since the alias may be used across TUs we use a more
deterministic naming convention, and add a `.local` suffix to the alias
name just as we do for relative vtables aliases.
Reviewed By: phosek
Differential Revision: https://reviews.llvm.org/D137982
This patch adds support for including binary ids in an indexed profile.
It adds a new field into the header that points to the offset of the
binary id section. The binary id section consists of a size of the
section, and a list of binary ids (if they are present) that consist
of two parts: length and data.
This patch guarantees that indexed profile is backwards compatible
after adding binary ids.
Differential Revision: https://reviews.llvm.org/D135929
In many cases, we can use an alias to avoid a symbolic relocations,
instead of using the public, interposable symbol. When the instrumented
function is in a COMDAT, we can use a hidden alias, and still avoid
references to discarded sections.
This version makes the new runtime test a Linux only test.
Reviewed By: phosek
Differential Revision: https://reviews.llvm.org/D137982
In https://reviews.llvm.org/D135127 we created the show flag
`--output-format` which was confusing because it behaved differently
than the same flag in the merge command. So, rename the flag to
`--show-format`. This also allows us to add the `text` option to mean
"normal text output" rather than "text-encoded profiles" like it does
for the merge command.
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D135467
Change the behavior of the `llvm-profdata show --debug-info=` command to dump a YAML file when using debug info correlation since it provides more information in a parseable format.
Reviewed By: yozhu, phosek
Differential Revision: https://reviews.llvm.org/D134770
Use the llvm flag `-pgo-function-entry-coverage` to create single byte "counters" to track functions coverage. This mode has significantly less size overhead in both code and data because
* We mark a function as "covered" with a store instead of an increment which generally requires fewer assembly instructions
* We use a single byte per function rather than 8 bytes per block
The trade off of course is that this mode only tells you if a function has been covered. This is useful, for example, to detect dead code.
When combined with debug info correlation [0] we are able to create an instrumented Clang binary that is only 150M (the vanilla Clang binary is 143M). That is an overhead of 7M (4.9%) compared to the default instrumentation (without value profiling) which has an overhead of 31M (21.7%).
[0] https://groups.google.com/g/llvm-dev/c/r03Z6JoN7d4
Reviewed By: kyulee
Differential Revision: https://reviews.llvm.org/D116180
Use the `llvm-profdata show` command to verify debug info for profile correlation using the `--debug-info` option.
Reviewed By: kyulee
Differential Revision: https://reviews.llvm.org/D118181
There is no need to compress the names string when correlating with
debug info since InstrProfReader will immediately uncompress it anyway.
This also removes the dependency on zlib in this case.
Reviewed By: kyulee
Differential Revision: https://reviews.llvm.org/D118176
When using debug info for profile correlation, avoid adding duplicate
functions in the synthetic Data section.
Before this patch, n duplicate function entries in the Data section would
cause counter values to be a factor of n larger. I built instrumented
clang with and without debug info correlation and got these summaries.
```
# With Debug Info Correlate
$ llvm-profdata show default.profdata
Instrumentation level: IR entry_first = 0
Total functions: 182530
Maximum function count: 52034
Maximum internal block count: 5763
# Without
$ llvm-profdata show default.profdata
Instrumentation level: IR entry_first = 0
Total functions: 183212
Maximum function count: 52034
Maximum internal block count: 5766
```
The slight difference in counts seem to be mostly from FileSystem and
Map functions and the difference in the number of instrumented functions
seems to come from missing debug info like destructors without source.
Reviewed By: kyulee
Differential Revision: https://reviews.llvm.org/D116051
There was a build failure on the `instrprof-debug-info-correlate.c` test
because zlib was missing so we need to require it to run the test.
Differential Revision: https://reviews.llvm.org/D115970
Extend `llvm-profdata` to read in a `.proflite` file and also a debug info file to generate a normal `.profdata` profile. This reduces the binary size by 8.4% when building an instrumented Clang binary without value profiling (164 MB vs 179 MB).
This work is part of the "lightweight instrumentation" RFC: https://groups.google.com/g/llvm-dev/c/r03Z6JoN7d4
This was first landed in https://reviews.llvm.org/D114566 but had to be reverted due to build errors.
Reviewed By: kyulee
Differential Revision: https://reviews.llvm.org/D115915
