22 Commits

Author SHA1 Message Date
Jan Voung
fa4fbaefde
Reapply: Use an abbrev to reduce size of VALUE_GUID records in ThinLTO summaries (#106165)
This retries #90692 which was reverted previously due to issues with
lld-available being set, even if the copy of lld is not built from
source.

This does not change any code compared to #90692 to address the
lld-available issue.
The main change w.r.t, lld-available is xfailing tests in PR #99056
(until a longer term fix is available).
2024-08-27 13:53:25 -04:00
Jan Voung
d71771dd27
Revert "Reapply "Use an abbrev to reduce size of VALUE_GUID records in ThinLTO summaries" (#90610)" (#91194)
Reverts llvm/llvm-project#90692

Breaking PPC buildbots. The bots are not meant to test LLD, but are
running a test that is using an old version of LLD without the change
(so is incompatible). Revert until a fix is found.
2024-05-06 21:37:07 +08:00
Jan Voung
28869a704e
Reapply "Use an abbrev to reduce size of VALUE_GUID records in ThinLTO summaries" (#90610) (#90692)
This reverts commit 2aabfc811670beb843074c765c056fff4a7b443b.

Add fixes to LLD and Gold tests missed in original change.

Co-authored-by: Jan Voung <jvoung@google.com>
2024-05-01 10:58:05 -07:00
Jan Voung
2aabfc8116
Revert "Use an abbrev to reduce size of VALUE_GUID records in ThinLTO summaries" (#90610)
Reverts llvm/llvm-project#90497
Broke some LLD tests.
2024-04-30 07:09:22 -07:00
Jan Voung
adabdc12f9
Use an abbrev to reduce size of VALUE_GUID records in ThinLTO summaries (#90497)
GUID often have content in the higher bits of a 64-bit entry so using
the unabbrev encoding is inefficient (lots of VBR control bits).
Instead, use an abbrev with two 32-bit fixed width chunks.
The abbrev also helps encode the "count" in one place instead of
in every record.

Reduces size of distributed backend summary files by 8.7% in one
example app.

Co-authored-by: Jan Voung <jvoung@google.com>
2024-04-30 06:26:09 -07:00
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
88fbc4d3df
[ThinLTO] Add tail call flag to call edges in summary (#74043)
This adds support for a HasTailCall flag on function call edges in the
ThinLTO summary. It is intended for use in aiding discovery of missing
frames from tail calls in profiled call stacks for MemProf of profiled
binaries that did not disable tail call elimination. A follow on change
will add the use of this new flag during MemProf context disambiguation.

The new flag is encoded in the bitcode along with either the hotness
flag from the profile, or the relative block frequency under the
-write-relbf-to-summary flag when there is no profile data.
Because we now will always have some additional call edge information, I
have removed the non-profile function summary record format, and we
simply encode the tail call flag along with a hotness type of none when
there is no profile information or relative block frequency. The change
of record format and name caused most of the test case changes.

I have added explicit testing of generation of the new tail call flag
into the bitcode and IR assembly format as part of the changes to
llvm/test/Bitcode/thinlto-function-summary-refgraph.ll. I have also
added round trip testing through assembly and bitcode to
llvm/test/Assembler/thinlto-summary.ll.
2023-12-06 08:41:44 -08:00
Teresa Johnson
3adc6e0308 [ThinLTO] Remove BlockCount for non partial sample profile builds
As pointed out in
https://discourse.llvm.org/t/undeterministic-thin-index-file/69985, the
block count added to distributed ThinLTO index files breaks incremental
builds on ThinLTO - if any linked file has a different number of BBs,
then the accumulated sum placed in the index files will change, causing
all ThinLTO backend compiles to be redone.

The block count is only used for scaling of partial sample profiles, and
was added in D80403 for D79831.

This patch simply removes this field from the index files of non partial
sample profile compiles, which is NFC on the output of the compiler.

We subsequently need to see if this can be removed for partial sample
profiles without signficant performance loss, or redesigned in a way
that does not destroy caching.

Differential Revision: https://reviews.llvm.org/D148746
2023-04-20 11:45:15 -07:00
Hiroshi Yamauchi
a7fa35a629 [ThinLTO] Compute the basic block count across modules.
Summary:
Count the per-module number of basic blocks when the module summary is computed
and sum them up during Thin LTO indexing.

This is used to estimate the working set size under the partial sample PGO.

This is split off of D79831.

Reviewers: davidxl, espindola

Subscribers: emaste, inglorion, hiraditya, MaskRay, steven_wu, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80403
2020-05-28 10:33:05 -07:00
Joel E. Denny
4e8b99a5c3 [Bitcode] Update CHECK-DAG usage in tests
This patch adjusts tests not to depend on deprecated FileCheck
behavior that permits overlapping matches within a block of
`CHECK-DAG` directives:

1. `thinlto-function-summary-originalnames.ll`: The directive with the
pattern `<COMBINED` is surely intended to match `<COMBINED ` (note the
trailing space), but it instead matches
`<COMBINED_GLOBALVAR_INIT_REFS`, for which there is a separate
directive.  With the deprecated behavior, both directives match the
latter text and neither match the former text.  I've adjusted the
former directive so it matches only the former text.

2. `thinlto-summary-local-5.0.ll`: Two directives have identical
patterns when they were clearly meant to have different patterns.

3. `upgrade-pointer-address-space.ll`: There are three identical
directives but only two occurrences of the matching text.  With the
deprecated behavior, they always match exactly the same text, so the
behavior can't have been useful.  I removed one of the directives and
converted the other two from `CHECK-DAG` to `CHECK`.

Reviewed By: probinson, aprantl

Differential Revision: https://reviews.llvm.org/D64036

llvm-svn: 365060
2019-07-03 17:31:43 +00:00
Joel E. Denny
9fa9c9368d [FileCheck] Add -allow-deprecated-dag-overlap to failing llvm tests
See https://reviews.llvm.org/D47106 for details.

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D47171

This commit drops that patch's changes to:

  llvm/test/CodeGen/NVPTX/f16x2-instructions.ll
  llvm/test/CodeGen/NVPTX/param-load-store.ll

For some reason, the dos line endings there prevent me from commiting
via the monorepo.  A follow-up commit (not via the monorepo) will
finish the patch.

llvm-svn: 336843
2018-07-11 20:25:49 +00:00
Teresa Johnson
f368101567 [ThinLTO] Serialize WithGlobalValueDeadStripping index flag for distributed backends
Summary:
A recent fix to drop dead symbols (r323633) did not work for ThinLTO
distributed backends because we lose the WithGlobalValueDeadStripping
set on the index during the thin link. This patch adds a new flags
record to the bitcode format for the index, and serializes this flag
for the combined index (it would always be 0 for the per-module index
generated by the compile step, so no need to serialize the new flags
record there until/unless we add another flag that applies to the
per-module indexes).

Generally this flag should always be set for the distributed backends,
which are necessarily performed after the thin link. However, if we were
to simply set this flag on the index applied to the distributed backends
(invoked via clang), we would lose the ability to disable dead stripping
via -compute-dead=false for debugging purposes.

Reviewers: grimar, pcc

Subscribers: mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D42799

llvm-svn: 324444
2018-02-07 04:05:59 +00:00
Peter Collingbourne
a0f371a106 Bitcode: Add a string table to the bitcode format.
Add a top-level STRTAB block containing a string table blob, and start storing
strings for module codes FUNCTION, GLOBALVAR, ALIAS, IFUNC and COMDAT in
the string table.

This change allows us to share names between globals and comdats as well
as between modules, and improves the efficiency of loading bitcode files by
no longer using a bit encoding for symbol names. Once we start writing the
irsymtab to the bitcode file we will also be able to share strings between
it and the module.

On my machine, link time for Chromium for Linux with ThinLTO decreases by
about 7% for no-op incremental builds or about 1% for full builds. Total
bitcode file size decreases by about 3%.

As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2017-April/111732.html

Differential Revision: https://reviews.llvm.org/D31838

llvm-svn: 300464
2017-04-17 17:51:36 +00:00
Teresa Johnson
02e98331c0 [ThinLTO] Use valueid instead of bitcode offsets in combined index file
Summary:
With the removal of support for lazy parsing of combined index summary
records (e.g. r267344), we no longer need to include the summary record
bitcode offset in the VST entries for definitions. Change the combined
index format to be similar to the per-module index format in using value
ids to cross-reference from the summary record to the VST entry (rather
than the summary record bitcode offset to cross-reference in the other
direction).

The visible changes are:
1) Add the value id to the combined summary records
2) Remove the summary offset from the combined VST records, which has
the following effects:
- No longer need the VST_CODE_COMBINED_GVDEFENTRY record, as all
  combined index VST entries now only contain the value id and
  corresponding GUID.
- No longer have duplicate VST entries in the case where there are
  multiple definitions of a symbol (e.g. weak/linkonce), as they all
  have the same value id and GUID.

An implication of #2 above is that in order to hook up an alias to the
correct aliasee based on the value id of the aliasee recorded in the
combined index alias record, we need to scan the entries in the index
for that GUID to find the one from the same module (i.e. the case where
there are multiple entries for the aliasee). But the reader no longer
has to maintain a special map to hook up the alias/aliasee.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19481

llvm-svn: 267712
2016-04-27 13:28:35 +00:00
Mehdi Amini
8fe6936e18 Add a version field in the bitcode for the summary
Differential Revision: http://reviews.llvm.org/D19456

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267318
2016-04-24 03:18:11 +00:00
Mehdi Amini
02fa65209c Relax test using CHECK-DAG instead of CHECK-NEXT
It seems we still have some ordering issue in the combined index
emission, but I can't figure out why right now.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267306
2016-04-24 00:25:15 +00:00
Mehdi Amini
363d83f808 Fix test stability (was sensitive to the path)
This is a fixup for r267304.
The test was sensitive to the path in a subtle way:
the index in memory is sorted by GUID, which are hashes
that include the source filename for local globals.
Teresa recently added a directive at the IR level, so
we can specify it here to make the test independent of
the path.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267305
2016-04-24 00:03:57 +00:00
Mehdi Amini
ae64eafd31 Store and emit original name in combined index
Summary:
As discussed in D18298, some local globals can't
be renamed/promoted (because they have a section, or because
they are referenced from inline assembly).
To be able to detect naming collision, we need to keep around
the "GUID" using their original name without taking the linkage
into account.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19454

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267304
2016-04-23 23:38:17 +00:00