This is an archive of the discontinued LLVM Phabricator instance.

Differential D78446

[MLIR] NFC Fix/clarify line in const usage rationale doc
ClosedPublic

Authored by bondhugula on Apr 18 2020, 10:44 PM.

Details

Reviewers
rriddle
mehdi_amini
Commits
rG9412e4c9c67a: [MLIR] NFC Fix/clarify line in const usage rationale doc
Summary

Update misleading line in conclusions. Although the application to IR
objects is stated earlier, the concluding section contradicts it in
isolation.

Diff Detail

Event Timeline

bondhugula created this revision.Apr 18 2020, 10:44 PM
Herald added a project: Restricted Project. · View Herald TranscriptApr 18 2020, 10:45 PM
Herald added subscribers: llvm-commits, frgossen, grosul1 and 11 others. · View Herald Transcript
rriddle accepted this revision.Apr 18 2020, 10:49 PM
This revision is now accepted and ready to land.Apr 18 2020, 10:49 PM
Harbormaster failed remote builds in B53884: Diff 258579!Apr 18 2020, 11:09 PM
Closed by commit rG9412e4c9c67a: [MLIR] NFC Fix/clarify line in const usage rationale doc (authored by bondhugula). · Explain WhyApr 18 2020, 11:58 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
mlir/
docs/
Rationale/
4 lines

Diff 258579

mlir/docs/Rationale/UsageOfConst.md

Show First 20 Lines • Show All 251 Lines • ▼ Show 20 Lines
pointer to their underlying operation. pointer to their underlying operation.
## Proposal: Remove `const` from IR objects ## Proposal: Remove `const` from IR objects
As we can see above, there is very little benefit to our const design and As we can see above, there is very little benefit to our const design and
significant cost, and given that the primary purpose of an IR is to represent significant cost, and given that the primary purpose of an IR is to represent
transformations of code, const is providing very little benefit. transformations of code, const is providing very little benefit.
As such, we propose eliminating support for const references in MLIR. This As such, we propose eliminating support for const references to IR objects in
implies the following changes to the codebase: MLIR. This implies the following changes to the codebase:
1. All of the const-duplicated accessors would be eliminated, e.g. 1. All of the const-duplicated accessors would be eliminated, e.g.
`Operation::getParent() const` would be removed. This is expected to remove `Operation::getParent() const` would be removed. This is expected to remove
approximately ~130 lines of code from just Operation.h alone. approximately ~130 lines of code from just Operation.h alone.
1. Const-only predicates would be changed to be non-const, e.g. 1. Const-only predicates would be changed to be non-const, e.g.
`Operation::isTerminator() const` would have the const removed. `Operation::isTerminator() const` would have the const removed.
1. Iterators and other types and functions that are templated to support 1. Iterators and other types and functions that are templated to support
`const` can have those template arguments removed. `const` can have those template arguments removed.
1. Types like `OpPointer` and `ConstOpPointer` that exist solely to propagate 1. Types like `OpPointer` and `ConstOpPointer` that exist solely to propagate
const can be entirely removed from the codebase. const can be entirely removed from the codebase.
1. We can close bugs complaining about const incorrectness in the IR. 1. We can close bugs complaining about const incorrectness in the IR.