This is an archive of the discontinued LLVM Phabricator instance.

Differential D109389

[MLIR][docs] Clarify language in pass restrictions
ClosedPublic

Authored by GMNGeoffrey on Sep 7 2021, 1:19 PM.

Details

Reviewers
rriddle
mehdi_amini
Commits
rG6da594596b8f: [MLIR][docs] Clarify language in pass restrictions
Summary

Right now all but the last bullet are relying on applied "must not" that
isn't there and the last bullet is a "must".

Diff Detail

Unit TestsFailed

TimeTest
10 msx64 debian > Flang.Evaluate::folding28.f90

Event Timeline

GMNGeoffrey created this revision.Sep 7 2021, 1:19 PM
Herald added subscribers: wrengr, Chia-hungDuan, dcaballe and 16 others. · View Herald TranscriptSep 7 2021, 1:19 PM
GMNGeoffrey requested review of this revision.Sep 7 2021, 1:19 PM
Herald added a project: Restricted Project. · View Herald TranscriptSep 7 2021, 1:19 PM
Herald added subscribers: stephenneuendorffer, nicolasvasilache. · View Herald Transcript
mehdi_amini accepted this revision.Sep 7 2021, 1:36 PM
This revision is now accepted and ready to land.Sep 7 2021, 1:36 PM
This revision was landed with ongoing or failed builds.Sep 7 2021, 1:41 PM
Closed by commit rG6da594596b8f: [MLIR][docs] Clarify language in pass restrictions (authored by GMNGeoffrey). · Explain Why
This revision was automatically updated to reflect the committed changes.
GMNGeoffrey added a commit: rG6da594596b8f: [MLIR][docs] Clarify language in pass restrictions.
Harbormaster completed remote builds in B122932: Diff 371167.Sep 7 2021, 2:18 PM

Revision Contents

PathSize
mlir/
docs/
23 lines

Diff 371167

mlir/docs/PassManagement.md

Show All 17 Lines
In MLIR, the main unit of abstraction and transformation is an In MLIR, the main unit of abstraction and transformation is an
[operation](LangRef.md/#operations). As such, the pass manager is designed to [operation](LangRef.md/#operations). As such, the pass manager is designed to
work on instances of operations at different levels of nesting. The structure of work on instances of operations at different levels of nesting. The structure of
the [pass manager](#pass-manager), and the concept of nesting, is detailed the [pass manager](#pass-manager), and the concept of nesting, is detailed
further below. All passes in MLIR derive from `OperationPass` and adhere to the further below. All passes in MLIR derive from `OperationPass` and adhere to the
following restrictions; any noncompliance will lead to problematic behavior in following restrictions; any noncompliance will lead to problematic behavior in
multithreaded and other advanced scenarios: multithreaded and other advanced scenarios:
* Modify any state referenced or relied upon outside the current being * Must not modify any state referenced or relied upon outside the current
operated on. This includes adding or removing operations from the parent being operated on. This includes adding or removing operations from the
block, changing the attributes(depending on the contract of the current parent block, changing the attributes(depending on the contract of the
operation)/operands/results/successors of the current operation. current operation)/operands/results/successors of the current operation.
* Modify the state of another operation not nested within the current * Must not modify the state of another operation not nested within the current
operation being operated on. operation being operated on.
* Other threads may be operating on these operations simultaneously. * Other threads may be operating on these operations simultaneously.
* Inspect the state of sibling operations. * Must not inspect the state of sibling operations.
* Other threads may be modifying these operations in parallel. * Other threads may be modifying these operations in parallel.
* Inspecting the state of ancestor/parent operations is permitted. * Inspecting the state of ancestor/parent operations is permitted.
* Maintain mutable pass state across invocations of `runOnOperation`. A pass * Must not maintain mutable pass state across invocations of `runOnOperation`.
may be run on many different operations with no guarantee of execution A pass may be run on many different operations with no guarantee of
order. execution order.
* When multithreading, a specific pass instance may not even execute on * When multithreading, a specific pass instance may not even execute on
all operations within the IR. As such, a pass should not rely on running all operations within the IR. As such, a pass should not rely on running
on all operations. on all operations.
* Maintain any global mutable state, e.g. static variables within the source * Must not maintain any global mutable state, e.g. static variables within the
file. All mutable state should be maintained by an instance of the pass. source file. All mutable state should be maintained by an instance of the
pass.
* Must be copy-constructible * Must be copy-constructible
* Multiple instances of the pass may be created by the pass manager to * Multiple instances of the pass may be created by the pass manager to
process operations in parallel. process operations in parallel.
When creating an operation pass, there are two different types to choose from When creating an operation pass, there are two different types to choose from
depending on the usage scenario: depending on the usage scenario:
### OperationPass : Op-Specific ### OperationPass : Op-Specific
▲ Show 20 Lines • Show All 1,187 Lines • Show Last 20 Lines