18 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
Teresa Johnson
1768898680 [MemProf] Control availability of hot/cold operator new from LTO link
Adds an LTO option to indicate that whether we are linking with an
allocator that supports hot/cold operator new interfaces. If not,
at the start of the LTO backends any existing memprof hot/cold
attributes are removed from the IR, and we also remove memprof metadata
so that post-LTO inlining doesn't add any new attributes.

This is done via setting a new flag in the module summary index. It is
important to communicate via the index to the LTO backends so that
distributed ThinLTO handles this correctly, as they are invoked by
separate clang processes and the combined index is how we communicate
information from the LTO link. Specifically, for distributed ThinLTO the
LTO related processes look like:
```
   # Thin link:
   $ lld --thinlto-index-only obj1.o ... objN.o -llib ...
   # ThinLTO backends:
   $ clang -x ir obj1.o -fthinlto-index=obj1.o.thinlto.bc -c -O2
   ...
   $ clang -x ir objN.o -fthinlto-index=objN.o.thinlto.bc -c -O2
```

It is during the thin link (lld --thinlto-index-only) that we have
visibility into linker dependences and want to be able to pass the new
option via -Wl,-supports-hot-cold-new. This will be recorded in the
summary indexes created for the distributed backend processes
(*.thinlto.bc) and queried from there, so that we don't need to know
during those individual clang backends what allocation library was
linked. Since in-process ThinLTO and regular LTO also use a combined
index, for consistency we query the flag out of the index in all LTO
backends.

Additionally, when the LTO option is disabled, exit early from the
MemProfContextDisambiguation handling performed during LTO, as this is
unnecessary.

Depends on D149117 and D149192.

Differential Revision: https://reviews.llvm.org/D149215
2023-05-08 08:02:21 -07:00
Teresa Johnson
cfad2d3a3d [MemProf] Context disambiguation cloning pass [patch 4/4]
Applies ThinLTO cloning decisions made during the thin link and
recorded in the summary index to the IR during the ThinLTO backend.

Depends on D141077.

Differential Revision: https://reviews.llvm.org/D149117
2023-05-05 16:26:32 -07:00
Teresa Johnson
04f3c5a71e Restore again "[MemProf] Context disambiguation cloning pass [patch 3/4]"
This reverts commit f09807ca9dda2f588298d8733e89a81105c88120, restoring
bfe7205975a63a605ff3faacd97fe4c1bf4c19b3 and follow on fix
e3e6bc699574550f2ed1de07f4e5bcdddaa65557, now that the nondeterminism
has been addressed by D149924.

Differential Revision: https://reviews.llvm.org/D141077
2023-05-05 13:27:33 -07:00
Teresa Johnson
f09807ca9d Revert "Restore "[MemProf] Context disambiguation cloning pass [patch 3/4]""
This reverts commit bfe7205975a63a605ff3faacd97fe4c1bf4c19b3, and follow
on fix e3e6bc699574550f2ed1de07f4e5bcdddaa65557, due to some remaining
instability exposed by the bot enabling expensive checks:
https://lab.llvm.org/buildbot/#/builders/42/builds/9842
2023-05-04 09:41:48 -07:00
Teresa Johnson
e3e6bc6995 [MemProf] Need to require asserts for tests that use -stats
Follow up to bfe7205975a63a605ff3faacd97fe4c1bf4c19b3 to require asserts
which is needed for the use of -stats. This showed up in the following
bot failure: https://lab.llvm.org/buildbot/#/builders/91/builds/16760
2023-05-04 07:34:16 -07:00
Teresa Johnson
bfe7205975 Restore "[MemProf] Context disambiguation cloning pass [patch 3/4]"
This reverts commit 6fbf022908c104a380fd1854fb96eafc64509366, restoring
commit bf6ff4fd4b735afffc65f92a4a79f6610e7174c3 with a fix for a bot
failure due to a previously unstable iteration order.

Differential Revision: https://reviews.llvm.org/D141077
2023-05-04 06:31:44 -07:00
Teresa Johnson
6fbf022908 Revert "[MemProf] Context disambiguation cloning pass [patch 3/4]"
This reverts commit bf6ff4fd4b735afffc65f92a4a79f6610e7174c3.

There is a bot failure where we are getting the correct remarks output
but in a different order. I'll need to investigate to see where we are
having nondeterministic behavior.
2023-05-03 14:08:54 -07:00
Teresa Johnson
bf6ff4fd4b [MemProf] Context disambiguation cloning pass [patch 3/4]
Applies cloning decisions to the IR, cloning functions and updating
calls. For Regular LTO, the IR is updated directly during function
assignment, whereas for ThinLTO it is recorded in the summary index
(a subsequent patch will apply to the IR via the index during the
ThinLTO backend.

The function assignment and cloning proceeds greedily, and we create new
clones as needed when we find an incompatible assignment of function
clones to callsite clones (i.e. when different callers need to invoke
different combinations of callsite clones).

Depends on D140949.

Differential Revision: https://reviews.llvm.org/D141077
2023-05-03 13:34:00 -07:00
Teresa Johnson
a4bdb27538 [MemProf] Use profiled lifetime access density directly
Now that the runtime tracks the lifetime access density directly, we can
use that directly in the threshold checks instead of less accurately
computing from other statistics.

Differential Revision: https://reviews.llvm.org/D149684
2023-05-02 15:19:34 -07:00
Teresa Johnson
a104e27030 Restore "[MemProf] Context disambiguation cloning pass [patch 2/3]"
This restores d0649a6ad8be778abf7569f502148d577f8bc6f1 (reverted in
commit 03bf59d275a16815dc5a2e3f279815554f7cd0ca), with fixes for bot
failures. Confirmed that gcc, which reproduced both failures, now
builds it fine.

Differential Revision: https://reviews.llvm.org/D140949
2023-04-21 19:38:46 -07:00
Teresa Johnson
03bf59d275 Revert "[MemProf] Context disambiguation cloning pass [patch 2/3]"
This reverts commit d0649a6ad8be778abf7569f502148d577f8bc6f1.

Reverting due to a number of bot failures that need investigation.
2023-04-21 14:37:42 -07:00
Teresa Johnson
d0649a6ad8 [MemProf] Context disambiguation cloning pass [patch 2/3]
Performs cloning on the CallsiteContextGraph (not on the IR or summary
index), in order to uniquely identify the allocation behavior of an
allocation call given its context. In order to do this, the graph is
recursively traversed starting from the allocation nodes, until we
identify a point where the allocation behavior is unambiguous (the edges
have a single allocation type). Nodes are then cloned as we unwind the
recursion. We try to perform the minimal amount of cloning required to
disambiguate the contexts.

The follow-on patch will contain the support for applying the cloning to
the IR.

Depends on D140908 and D145836.

Differential Revision: https://reviews.llvm.org/D140949
2023-04-21 14:31:44 -07:00
Teresa Johnson
fe27495be2 [MemProf] Context disambiguation cloning pass [patch 1b/3]
Adds support for building the graph in ThinLTO from MemProf summaries.

Follow-on patches will contain the support for cloning on the graph and
in the IR.

Depends on D140908.

Differential Revision: https://reviews.llvm.org/D145836
2023-03-22 14:57:53 -07:00