[all-commits] [llvm/llvm-project] 0c29f4: [MLIR] Fix dialect conversion cancelRootUpdate

[Uday Bondhugula via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0c29f45ac9e8e67a6481c0810e2e335a12bf3877
      https://github.com/llvm/llvm-project/commit/0c29f45ac9e8e67a6481c0810e2e335a12bf3877
  Author: Uday Bondhugula <uday at polymagelabs.com>
  Date:   2021-07-06 (Tue, 06 Jul 2021)

  Changed paths:
    M mlir/lib/Transforms/Utils/DialectConversion.cpp

  Log Message:
  -----------
  [MLIR] Fix dialect conversion cancelRootUpdate

Fix dialect conversion ConversionPatternRewriter::cancelRootUpdate: the
erasure of operations here from the list of root update was off by one.
Should have been:
```
rootUpdates.erase(rootUpdates.begin() + (rootUpdates.rend() - it - 1));
```
instead of
```
rootUpdates.erase(rootUpdates.begin() + (rootUpdates.rend() - it));
```

or more directly:
```
rootUpdates.erase(it.base() - 1)
```

While on this, add an assertion to improve dev experience when a cancel is
called on an op on which a root update hasn't been started.

Differential Revision: https://reviews.llvm.org/D105397