99 Commits

Author SHA1 Message Date
Mingming Liu
78a195e100
Reland the reland "[PGO][GlobalValue][LTO]In GlobalValues::getGlobalIdentifier, use semicolon as delimiter for local-linkage varibles. " (#75954)
Simplify the compiler-rt test to make it more general for different
platforms, and use `*DAG` matchers for lines that may be emitted
out-of-order.
- The compiler-rt test passed on a Windows machine. Previously name
matchers don't work for MSVC mangling
(https://lab.llvm.org/buildbot/#/builders/127/builds/59907)
- `*DAG` matchers fixed the error in
https://lab.llvm.org/buildbot/#/builders/94/builds/17924

This is the second reland and fixed errors caught in first reland
(https://github.com/llvm/llvm-project/pull/75860)

**Original commit message**
Commit fe05193 (phab D156569), IRPGO names uses format
`[<filepath>;]<linkage-name>` while prior format is
`[<filepath>:<mangled-name>`. The format change would break the use case
demonstrated in (updated)
`llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll` and
`compiler-rt/test/profile/instrprof-thinlto-indirect-call-promotion.cpp`

This patch changes `GlobalValues::getGlobalIdentifer` to use the
semicolon.

To elaborate on the scenario how things break without this PR
1. IRPGO raw profiles stores (compressed) IRPGO names of functions in
one section, and per-function profile data in another section. The
[NameRef](fc715e4cd9/compiler-rt/include/profile/InstrProfData.inc (L72))
field in per-function profile data is the MD5 hash of IRPGO names.
2. When raw profiles are converted to indexed format profiles, the
profiled address is
[mapped](fc715e4cd9/llvm/lib/ProfileData/InstrProf.cpp (L876-L885))
to the MD5 hash of the callee.
3. In `pgo-instr-use` thin-lto prelink pipeline, MD5 hash of IRPGO names
will be
[annotated](fc715e4cd9/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp (L1707))
as value profiles, and used to import indirect-call-prom candidates. If
the annotated MD5 hash is computed from the new format while import uses
the prior format, the callee cannot be imported.

*
`compiler-rt/test/profile/instrprof-thinlto-indirect-call-promotion.cpp`
is added to have an end-to-end test.
* `llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll`
is updated to have better test coverage from another aspect (as runtime
tests are more sensitive to the environment and may be skipped by some
contributors)
2023-12-19 12:25:56 -08:00
Mingming Liu
6ce23ea0ab
Revert "Reland "[PGO][GlobalValue][LTO]In GlobalValues::getGlobalIdentifier, use semicolon as delimiter for local-linkage varibles. "" (#75888)
Reverts llvm/llvm-project#75860
- Mangled name mismatch on Windows
(https://lab.llvm.org/buildbot/#/builders/127/builds/59907/steps/8/logs/stdio)
2023-12-18 19:31:18 -08:00
Mingming Liu
c5871712ae
Reland "[PGO][GlobalValue][LTO]In GlobalValues::getGlobalIdentifier, use semicolon as delimiter for local-linkage varibles. " (#75860)
Fixed build-bot failures caught by post-submit tests
1) Add the list of command line tools needed by new compiler-rt test into dependency.
2) Use `starts_with` to replace deprecated `startswith`.

**Original commit message**
Commit fe05193 (phab D156569), IRPGO names uses format
`[<filepath>;]<linkage-name>` while prior format is
`[<filepath>:<mangled-name>`. The format change would break the use case
demonstrated in (updated)
`llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll` and
`compiler-rt/test/profile/instrprof-thinlto-indirect-call-promotion.cpp`

This patch changes `GlobalValues::getGlobalIdentifer` to use the
semicolon.

To elaborate on the scenario how things break without this PR
1. IRPGO raw profiles stores (compressed) IRPGO names of functions in
one section, and per-function profile data in another section. The
[NameRef](fc715e4cd9/compiler-rt/include/profile/InstrProfData.inc (L72))
field in per-function profile data is the MD5 hash of IRPGO names.
2. When raw profiles are converted to indexed format profiles, the
profiled address is
[mapped](fc715e4cd9/llvm/lib/ProfileData/InstrProf.cpp (L876-L885))
to the MD5 hash of the callee.
3. In `pgo-instr-use` thin-lto prelink pipeline, MD5 hash of IRPGO names
will be
[annotated](fc715e4cd9/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp (L1707))
as value profiles, and used to import indirect-call-prom candidates. If
the annotated MD5 hash is computed from the new format while import uses
the prior format, the callee cannot be imported.

*
`compiler-rt/test/profile/instrprof-thinlto-indirect-call-promotion.cpp`
is added to have an end-to-end test.
* `llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll`
is updated to have better test coverage from another aspect (as runtime
tests are more sensitive to the environment and may be skipped by some
contributors)
2023-12-18 17:43:40 -08:00
Mingming Liu
3aa5d71127
Revert "[PGO][GlobalValue][LTO]In GlobalValues::getGlobalIdentifier, use semicolon as delimiter for local-linkage varibles." (#75835)
Reverts llvm/llvm-project#74008

The compiler-rt test failed due to `llvm-dis` not found
(https://lab.llvm.org/buildbot/#/builders/127/builds/59884)
Will revert and investigate how to require the proper dependency.
2023-12-18 09:39:55 -08:00
Mingming Liu
245cddae70
[PGO][GlobalValue][LTO]In GlobalValues::getGlobalIdentifier, use semicolon as delimiter for local-linkage varibles. (#74008)
Commit fe05193 (phab D156569), IRPGO names uses format
`[<filepath>;]<linkage-name>` while prior format is
`[<filepath>:<mangled-name>`. The format change would break the use case
demonstrated in (updated)
`llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll` and
`compiler-rt/test/profile/instrprof-thinlto-indirect-call-promotion.cpp`

This patch changes `GlobalValues::getGlobalIdentifer` to use the
semicolon.

To elaborate on the scenario how things break without this PR
1. IRPGO raw profiles stores (compressed) IRPGO names of functions in
one section, and per-function profile data in another section. The
[NameRef](fc715e4cd9/compiler-rt/include/profile/InstrProfData.inc (L72))
field in per-function profile data is the MD5 hash of IRPGO names.
2. When raw profiles are converted to indexed format profiles, the
profiled address is
[mapped](fc715e4cd9/llvm/lib/ProfileData/InstrProf.cpp (L876-L885))
to the MD5 hash of the callee.
3. In `pgo-instr-use` thin-lto prelink pipeline, MD5 hash of IRPGO names
will be
[annotated](fc715e4cd9/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp (L1707))
as value profiles, and used to import indirect-call-prom candidates. If
the annotated MD5 hash is computed from the new format while import uses
the prior format, the callee cannot be imported.

*`compiler-rt/test/profile/instrprof-thinlto-indirect-call-promotion.cpp`
is added to have an end-to-end test.
* `llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll`
is updated to have better test coverage from another aspect (as runtime
tests are more sensitive to the environment and may be skipped by some
contributors)
2023-12-18 09:10:39 -08:00
lifengxiang1025
340cb19e15
[MemProf] Expand optimization scope to internal linkage function (#73236)
Now MemProf can't do IR annotation right in the local linkage function
and global initial function __cxx_global_var_init. In llvm-profdata
which convert raw memory profile to memory profile, it uses function
name in dwarf to create GUID. But when llvm consumes memory profile, it
use `getIRPGOFuncName` or `getPGOFuncName` which returns local linkage
function as `FileName;FunctionName` or `FileName:FunctionName` to get
function name and create GUID. So profile creator's GUID is not same as
profile consumer.
So I think MemProf should be used with `unique-internal-linkage-names`
and don't use PGOFuncName.
__cxx_global_var_init is created later than where
UniqueInternalLinkageNames works. So I add uniq suffix to
__cxx_global_var_init additionally.

Co-authored-by: lifengxiang <lifengxiang.1025@bytedance.com>
2023-12-01 14:20:19 +08:00
Ellis Hoag
b0154c36d6
[InstrProf] Add pgo use block coverage test (#72443)
Back in https://reviews.llvm.org/D124490 we added a block coverage mode
that instruments a subset of basic blocks using single byte counters to
get coverage for the whole function.

This commit adds a test to make sure that we correctly assign branch
weights based on the coverage profile.

I noticed this test was missing after seeing that we had no coverage on
`PGOUseFunc::populateCoverage()`

https://lab.llvm.org/coverage/coverage-reports/coverage/Users/buildslave/jenkins/workspace/coverage/llvm-project/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp.html#L1383
2023-11-20 09:25:33 -06:00
Teresa Johnson
87f5e22987
[MemProf] Tolerate missing leaf debug frames (#71233)
Loosen up the matching so that a missing leaf debug frame in the profile
does not prevent matching an allocation context if we can match further
up the inlined call context. This relies on the pre-inliner, which was
already the default when performing normal PGO feedback along with the
MemProf feedback, but to ensure matching is not affected by the presence
of PGO, enable the pre-inliner for MemProf feedback as well.
2023-11-03 21:01:07 -07:00
Teresa Johnson
2446439f51
[MemProf] Handle profiles with missing column numbers (#70520)
Detect when we are matching a memprof profile with no column numbers,
and in that case treat all column numbers as 0 when matching. The
profiled binary might have been built with -gno-column-info, for
example.
2023-10-30 13:19:37 -07:00
Matthias Braun
e3cf80c5c1
BlockFrequencyInfoImpl: Avoid big numbers, increase precision for small spreads
BlockFrequencyInfo calculates block frequencies as Scaled64 numbers but as a last step converts them to unsigned 64bit integers (`BlockFrequency`). This improves the factors picked for this conversion so that:

* Avoid big numbers close to UINT64_MAX to avoid users overflowing/saturating when adding multiply frequencies together or when multiplying with integers. This leaves the topmost 10 bits unused to allow for some room.
* Spread the difference between hottest/coldest block as much as possible to increase precision.
* If the hot/cold spread cannot be represented loose precision at the lower end, but keep the frequencies at the upper end for hot blocks differentiable.
2023-10-24 20:27:39 -07:00
Teresa Johnson
ca31f821f2 [MemProf] Convert PGO raw profile to text format
This avoids the need to regenerate the PGO raw profile on version
changes. Modify the update script to autogenerate new PGO proftext
inputs.

Differential Revision: https://reviews.llvm.org/D156460
2023-07-27 11:08:14 -07:00
Snehasish Kumar
a1bbf5ac3c [memprof] Record BuildIDs in the raw profile.
This patch adds support for recording BuildIds usng the sanitizer
ListOfModules API. We add another entry to the SegmentEntry struct and
change the memprof raw version.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D145190
2023-03-14 18:16:38 +00:00
Snehasish Kumar
debe80cb8d Revert "[memprof] Record BuildIDs in the raw profile."
This reverts commit 287177a47a396ca6cc0bef7696108cdaa0c68e5f.
2023-03-13 20:09:46 +00:00
Snehasish Kumar
287177a47a [memprof] Record BuildIDs in the raw profile.
This patch adds support for recording BuildIds usng the sanitizer
ListOfModules API. We add another entry to the SegmentEntry struct and
change the memprof raw version.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D145190
2023-03-13 19:28:38 +00:00
Snehasish Kumar
e99b5ad383 [memprof] Add scripts to automate testdata regeneration.
The memprof profiles and binaries need to be updated in case of version
updates. This change adds three scripts for llvm-profdata, clang and
llvm tests where memprof profiles are used as inputs. Also update the
tests, profiles and binaries in this change. Change based on the review
suggestions in D145023.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D145644
2023-03-09 19:54:23 +00:00
Teresa Johnson
ee73d240ab [MemProf] Collect access density statistics during profiling
Track min/max/avg access density (accesses per byte and accesses per
byte per lifetime second) metrics directly during profiling. This allows
more accurate use of these metrics in profile analysis and use, instead
of trying to compute them from already aggregated data in the profile.

This required regenerating some of the raw profile and executable inputs
for a few tests. While here, make the llvm-profdata memprof tests more
resilient to differences in things like memory mapping, timestamps and
cpu ids to make future test updates easier.

Differential Revision: https://reviews.llvm.org/D141558
2023-01-12 17:53:23 -08:00
Matt Arsenault
a74c5707be Fix some test files with executable permissions 2022-12-02 17:12:03 -05:00
Wolfgang Pieb
b43a1d1bd9 [PGO] Do not create block count annotations when all weights are 0,
avoiding an assertion.

A BB with a nonzero count, whose successor blocks all have 0 counts, could
cause an assertion. Don't create any branch weights in this case.

Reviewed By: xur

Differential Revision: https://reviews.llvm.org/D134203
2022-10-13 14:57:42 -07:00
Teresa Johnson
b1926f308f Restore "[MemProf] Memprof profile matching and annotation"
This reverts commit 794b7ea960ccc3222f2af582efadbc5e5c464292, and
thus restores commit a212d8da94d08e229aa8d65283e4b116310bba10, and
follow on fixes 0cd6763fa93159b84d70a5bb602c24996acaafaa,
e9ff53d42feac7fc157718523275619a8106f2f3, and
37c6a25e9ab230e5e21fa34e246d9fec55275df0.

Use a hash function (BLAKE3) instead of hash_combine/hash_code which are
not guaranteed to be stable across executions.

Additionally, it adds a "REQUIRES: x86_64-linux" to the tests that have
raw profile inputs to avoid failures on big endian bots.

Reviewers: snehasish, davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D128142
2022-09-23 11:38:47 -07:00
Teresa Johnson
794b7ea960 Revert "[MemProf] Memprof profile matching and annotation"
This reverts commit a212d8da94d08e229aa8d65283e4b116310bba10, and follow
on fixes 0cd6763fa93159b84d70a5bb602c24996acaafaa,
e9ff53d42feac7fc157718523275619a8106f2f3, and
37c6a25e9ab230e5e21fa34e246d9fec55275df0.

After re-reading the documentation for hash_combine, I don't think this
is the appropriate hash function to use for computing the hash to use as
a stack id in the metadata, since it is not guaranteed to produce stable
values across executions. I have not hit this problem, but plan to
switch to using an MD5 hash. I am hitting an issue with one of the bots
(https://lab.llvm.org/buildbot/#/builders/171/builds/20732)
where the values produced are only the lower 32 bits of the expected
hash values, however, which I assume is related to the implementation of
hash_combine and hash_code.

I believe I fixed all of the other bot failures with the follow on fixes,
which I'll merge into the new version before reapplying.
2022-09-22 16:08:03 -07:00
Teresa Johnson
a212d8da94 [MemProf] Memprof profile matching and annotation
Profile matching and IR annotation for memprof profiles.

See also related RFCs:
RFC: Sanitizer-based Heap Profiler [1]
RFC: A binary serialization format for MemProf [2]
RFC: IR metadata format for MemProf [3]*

* Note that the IR metadata format has changed from the RFC during
implementation, as described in the preceeding patch adding the basic
metadata and verification support.

The matching is performed during the normal PGO annotation phase, to
ensure that the inlines applied in the IR at that point are a subset
of the inlines in the profiled binary and thus reflected in the
profile's call stacks. This is important because the call frames are
associated with functions in the profile based on the inlining in the
symbolized call stacks, and this simplifies locating the subset of
profile data relevant for matching onto each function's IR.

The PGOInstrumentationUse pass is enhanced to perform matching for
whatever combination of memprof and regular PGO profile data exists in
the profile.

Using the utilities introduced in D128854:
The memprof profile data for each context is converted to "cold" or
"notcold" based on parameterized thresholds for size, access count, and
lifetime. The memprof allocation contexts are trimmed to the minimal
amount of context required to uniquely identify whether the context is
cold or not cold. For allocations where all profiled contexts have the
same allocation type, no memprof metadata is attached and instead the
allocation call is directly annotated with an attribute specifying the
alloction type. This is the same attributed that will be applied to
allocation calls once cloned for different contexts, and later used
during LibCall simplification to emit allocation hints [4].

Depends on D128141 and D128854.

[1] https://lists.llvm.org/pipermail/llvm-dev/2020-June/142744.html
[2] https://lists.llvm.org/pipermail/llvm-dev/2021-September/153007.html
[3] https://discourse.llvm.org/t/rfc-ir-metadata-format-for-memprof/59165
[4] ab87cf382d

Differential Revision: https://reviews.llvm.org/D128142
2022-09-22 12:48:31 -07:00
Rong Xu
0caa4a9559 [PGO] Support PGO annotation of CallBrInst
We currently instrument CallBrInst but do not annotate it with
the branch weight. This patch enables PGO annotation of CallBrInst.

Differential Revision: https://reviews.llvm.org/D133040
2022-09-01 14:13:50 -07:00
Rong Xu
d7ef0c3970 [llvm-profdata] Improve profile supplementation
Current implementation promotes a non-cold function in the SampleFDO profile
into a hot function in the FDO profile. This is too aggressive. This patch
promotes a hot functions in the SampleFDO profile into a hot function, and a
warm function in SampleFDO into a warm function in FDO.

Differential Revision: https://reviews.llvm.org/D132601
2022-08-29 16:50:42 -07:00
Fangrui Song
9ff36df5a4 [PGO][InstrProf][test] Convert to opaque pointers and fix some stale tests 2022-07-16 11:42:35 -07:00
Rong Xu
5e0443292b [PGO] Report number of counts being dropped when a hash-mismatch happens
This patch reports number of counts being dropped when a hash-mismatch
happens. This information will be helpful to the users -- if the dropped
counts are large, the user should redo the instrumentation build and
recollect the profile.

Differential Revision: https://reviews.llvm.org/D129001
2022-07-15 14:53:59 -07:00
Rong Xu
4a40fa82c0 [PGO] Don't cross reference CSFDO profile and non-CSFDO profile
Don't cross reference CSFDO profile and non-CSFDO profile when
checking the function hash. Only return hash_mismatch when
CS bits match, and return unknown_function otherwise.

Differential Revision: https://reviews.llvm.org/D129000
2022-07-15 13:57:23 -07:00
Paul Kirth
bac6cd5bf8 [misexpect] Re-implement MisExpect Diagnostics
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.

New checks rely on 2 invariants:

1) For frontend instrumentation, MD_prof branch_weights will always be
   populated before llvm.expect intrinsics are lowered.

2) for IR and sample profiling, llvm.expect intrinsics will always be
   lowered before branch_weights are populated from the IR profiles.

These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.

Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D115907
2022-04-19 21:23:48 +00:00
Jorge Gorbe Moya
fc7573f29c Revert "[misexpect] Re-implement MisExpect Diagnostics"
This reverts commit 46774df307159444d65083c2fd82f8574f0ab1d9.
2022-03-31 14:54:41 -07:00
Paul Kirth
46774df307 [misexpect] Re-implement MisExpect Diagnostics
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.

New checks rely on 2 invariants:

1) For frontend instrumentation, MD_prof branch_weights will always be
   populated before llvm.expect intrinsics are lowered.

2) for IR and sample profiling, llvm.expect intrinsics will always be
   lowered before branch_weights are populated from the IR profiles.

These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.

Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D115907
2022-03-31 17:38:21 +00:00
Paul Kirth
90cb325abd Revert "[misexpect] Re-implement MisExpect Diagnostics"
This reverts commit 2add3fbd976d7b80a3a7fc14ef0deb9b1ca6beee.
2022-03-29 06:20:30 +00:00
Paul Kirth
2add3fbd97 [misexpect] Re-implement MisExpect Diagnostics
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.

New checks rely on 2 invariants:

1) For frontend instrumentation, MD_prof branch_weights will always be
   populated before llvm.expect intrinsics are lowered.

2) for IR and sample profiling, llvm.expect intrinsics will always be
   lowered before branch_weights are populated from the IR profiles.

These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.

Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D115907
2022-03-28 23:30:04 +00:00
Paul Kirth
964398ccb1 Revert "Revert "Revert "[misexpect] Re-implement MisExpect Diagnostics"""
This reverts commit 6cf560d69a222bff4af4e1d092437fd77f0f981c.
2022-03-18 00:21:33 +00:00
Paul Kirth
6cf560d69a Revert "Revert "[misexpect] Re-implement MisExpect Diagnostics""
I mistakenly reverted my commit, so I'm relanding it.

This reverts commit 10866a1df4a82cdc54187330c509a2d46235455d.
2022-03-18 00:04:22 +00:00
Paul Kirth
10866a1df4 Revert "[misexpect] Re-implement MisExpect Diagnostics"
This reverts commit e7749d4713a5ec886011ceb0fc821c6723061724.
2022-03-17 23:54:26 +00:00
Paul Kirth
e7749d4713 [misexpect] Re-implement MisExpect Diagnostics
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.

New checks rely on 2 invariants:

1) For frontend instrumentation, MD_prof branch_weights will always be
   populated before llvm.expect intrinsics are lowered.

2) for IR and sample profiling, llvm.expect intrinsics will always be
   lowered before branch_weights are populated from the IR profiles.

These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.

Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.

Differential Revision: https://reviews.llvm.org/D115907
2022-03-17 23:46:23 +00:00
Matthias Braun
6a383369f9 PGOInstrumentation, GCOVProfiling: Split indirectbr critical edges regardless of PHIs
The `SplitIndirectBrCriticalEdges` function was originally designed for
`CodeGenPrepare` and skipped splitting of edges when the destination
block didn't contain any `PHI` instructions. This only makes sense when
reducing COPYs like `CodeGenPrepare`. In the case of
`PGOInstrumentation` or `GCOVProfiling` it would result in missed
counters and wrong result in functions with computed goto.

Differential Revision: https://reviews.llvm.org/D120096
2022-02-23 16:27:37 -08:00
Rong Xu
de620f5b13 [CSPGO] Fix lost IRPGOFlag in CSPGO instrumentation
The IRPGOFlag symbol (__llvm_profile_raw_version) is dropped when
identified as non-prevailing for either regular or thin LTO during
the mixed-LTO mode compilation. This happens in the module where
IRPGOFlag is marked as non-prevailing. This variable
is emitted in the final object from the prevailing module.

This is still problematic because we currently query this symbol
to coordinate some actions between PGOInstrumentation pass
and InstrProfiling lowering pass, like whether to do value
profiling, whether to do comdat renaming.

This problem is bought up by YolandaCY in
https://reviews.llvm.org/D107034
YolandCY reported unresolved symbol linker errors in
CSPGO instrumentation build for chromium.

This patch let LTO retain IRPGOFlag decl by adding it to
CompilerUsed list and relax the check in isIRPGOFlagSet() when
doing the InstrProfiling lowering.

The test case in the patch is from D107034
<https://reviews.llvm.org/D107034>.

Differential Revision: https://reviews.llvm.org/D108581
2021-08-24 09:41:29 -07:00
Florian Hahn
ed9df5bd2f
[Passes] Run sinking/hoisting in SimplifyCFG earlier.
Hoisting and sinking instructions out of conditional blocks enables
additional vectorization by:

1. Executing memory accesses unconditionally.
2. Reducing the number of instructions that need predication.

After disabling early hoisting / sinking, we miss out on a few
vectorization opportunities. One of those is causing a ~10% performance
regression in one of the Geekbench benchmarks on AArch64.

This patch tires to recover the regression by running hoisting/sinking
as part of a SimplifyCFG run after LoopRotate and before LoopVectorize.

Note that in the legacy pass-manager, we run LoopRotate just before
vectorization again and there's no SimplifyCFG run in between, so the
sinking/hoisting may impact the later run on LoopRotate. But the impact
should be limited and the benefit of hosting/sinking at this stage
should outweigh the risk of not rotating.

Compile-time impact looks slightly positive for most cases.
http://llvm-compile-time-tracker.com/compare.php?from=2ea7fb7b1c045a7d60fcccf3df3ebb26aa3699e5&to=e58b4a763c691da651f25996aad619cb3d946faf&stat=instructions

NewPM-O3: geomean -0.19%
NewPM-ReleaseThinLTO: geoman -0.54%
NewPM-ReleaseLTO-g: geomean -0.03%

With a few benchmarks seeing a notable increase, but also some
improvements.

Alternative to D101290.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D101468
2021-04-30 12:23:57 +01:00
Matthew Voss
6da7d31416 [llvm-profdata] Emit Error when Invalid MemOpSize Section is Created by llvm-profdata
Under certain (currently unknown) conditions, llvm-profdata is outputting
profiles that have two consecutive entries in the MemOPSize section for the
value 0. This causes the PGOMemOPSizeOpt pass to output an invalid switch
instruction with two cases for 0. As mentioned, we’re not quite sure what’s
causing this to happen, but this patch prevents llvm-profdata from outputting a
profile that has this problem and gives an error with a request for a
reproducible.

Differential Revision: https://reviews.llvm.org/D92074
2021-02-23 12:51:54 -08:00
Sriraman Tallam
9a81a4ef79 Emit metadata when instr. profiles hash mismatch occurs.
This patch emits "instr_prof_hash_mismatch" function annotation metadata if
there is a hash mismatch while applying instrumented profiles.

During the PGO optimized build using instrumented profiles, if the CFG of
the function has changed since generating the profile, a hash mismatch is
encountered. This patch emits this information as annotation metadata. We
plan to use this with Propeller which is done at the machine IR level.
Propeller is usually applied on top of PGO and a hash mismatch during
PGO could be used to detect source drift.

Differential Revision: https://reviews.llvm.org/D95495
2021-01-29 12:56:01 -08:00
Rong Xu
0abd744597 [PGO] Use the sum of profile counts to fix the function entry count
Raw profile count values for each BB are not kept after profile
annotation. We record function entry count and branch weights
and use them to compute the count when needed.  This mechanism
works well in a perfect world, but often breaks in real programs,
because of number prevision, inconsistent profile, or bugs in
BFI). This patch uses sum of profile count values to fix
function entry count to make the BFI count close to real profile
counts.

Differential Revision: https://reviews.llvm.org/D61540
2020-12-16 13:37:43 -08:00
Rong Xu
54e03d03a7 [PGO] Verify BFI counts after loading profile data
This patch adds the functionality to compare BFI counts with real
profile
counts right after reading the profile. It will print remarks under
-Rpass-analysis=pgo, or the internal option -pass-remarks-analysis=pgo.

Differential Revision: https://reviews.llvm.org/D91813
2020-12-14 15:56:10 -08:00
Roman Lebedev
6861d938e5
Revert "clang-misexpect: Profile Guided Validation of Performance Annotations in LLVM"
See discussion in https://bugs.llvm.org/show_bug.cgi?id=45073 / https://reviews.llvm.org/D66324#2334485
the implementation is known-broken for certain inputs,
the bugreport was up for a significant amount of timer,
and there has been no activity to address it.
Therefore, just completely rip out all of misexpect handling.

I suspect, fixing it requires redesigning the internals of MD_misexpect.
Should anyone commit to fixing the implementation problem,
starting from clean slate may be better anyways.

This reverts commit 7bdad08429411e7d0ecd58cd696b1efe3cff309e,
and some of it's follow-ups, that don't stand on their own.
2020-11-14 13:12:38 +03:00
Hiroshi Yamauchi
3d6f53018f [PGO] Include the mem ops into the function hash.
To avoid hash collisions when the only difference is in mem ops.
2020-07-30 09:26:20 -07:00
Hiroshi Yamauchi
ae7589e1f1 Revert "[PGO] Include the mem ops into the function hash."
This reverts commit 120e66b3418b37b95fc1dbbb23e296a602a24fa8.

Due to a buildbot failure.
2020-07-29 15:04:57 -07:00
Hiroshi Yamauchi
120e66b341 [PGO] Include the mem ops into the function hash.
To avoid hash collisions when the only difference is in mem ops.

Differential Revision: https://reviews.llvm.org/D84782
2020-07-29 13:59:40 -07:00
Wei Mi
a23f62343c Supplement instr profile with sample profile.
PGO profile is usually more precise than sample profile. However, PGO profile
needs to be collected from loadtest and loadtest may not be representative
enough to the production workload. Sample profile collected from production
can be used as a supplement -- for functions cold in loadtest but warm/hot
in production, we can scale up the related function in PGO profile if the
function is warm or hot in sample profile.

The implementation contains changes in compiler side and llvm-profdata side.
Given an instr profile and a sample profile, for a function cold in PGO
profile but warm/hot in sample profile, llvm-profdata will either mark
all the counters in the profile to be -1 or scale up the max count in the
function to be above hot threshold, depending on the zero counter ratio in
the profile. The assumption is if there are too many counters being zero
in the function profile, the profile is more likely to cause harm than good,
then llvm-profdata will mark all the counters to be -1 indicating the
function is hot but the profile is unaccountable. In compiler side, if a
function profile with all -1 counters is seen, the function entry count will
be set to be above hot threshold but its internal profile will be dropped.

In the long run, it may be useful to let compiler support using PGO profile
and sample profile at the same time, but that requires more careful design
and more substantial changes to make two profiles work seamlessly. The patch
here serves as a simple intermediate solution.

Differential Revision: https://reviews.llvm.org/D81981
2020-07-27 20:17:40 -07:00
Rong Xu
1dd39b1133 [PGO] Fix incorrect function entry count
Function entry count might be zero after the profile counts reset and
before reentry to the function.

Zero profile entry count is very bad as the profile count from BFI will
be wrong.

A simple fix is to set the profile entry count to 1 if there are
non-zero profile counts in this function.

Differential Revision: https://reviews.llvm.org/D84378
2020-07-24 17:39:55 -07:00
Rong Xu
dcf1bca0de Revert "[PGO][InstrProf] Do not promote count if the exit blocks contains ret instruction"
This reverts commit 867ef4472d8e57384c929e4f06b74d1ac8883a99.
2020-07-24 17:33:49 -07:00
Rong Xu
867ef4472d [PGO][InstrProf] Do not promote count if the exit blocks contains ret instruction
Forgot including the tests in the commit 6fdc6f6c7d34af60c4.
2020-07-24 17:23:33 -07:00