[MLIR] `getRegisteredOperationsByDialect` comparator lambdas return int instead of bool, causing incorrect operation filtering

[rpavlovicTT]

The implementation of MLIRContext::getRegisteredOperationsByDialect uses std::lower_bound and std::upper_bound with comparator lambdas that return the result of StringRef::compare() directly (an int), instead of a boolean. Since these standard algorithms require comparators returning bool representing a strict weak ordering, returning an int causes undefined behavior and leads to incorrect or empty results when filtering operations by dialect.

Proposed fix:

// lower_bound comparator
[](const RegisteredOperationName &lhs, StringRef dialectName) {
  return lhs.getDialect().getNamespace() < dialectName;
}

// upper_bound comparator
[](StringRef dialectName, const RegisteredOperationName &rhs) {
  return dialectName < rhs.getDialect().getNamespace();
}

[llvmbot]

@llvm/issue-subscribers-mlir

Author: Radenko Pavlovic (rpavlovicTT)

The implementation of `MLIRContext::getRegisteredOperationsByDialect` uses std::lower_bound and std::upper_bound with comparator lambdas that return the result of StringRef::compare() directly (an int), instead of a boolean. Since these standard algorithms require comparators returning bool representing a strict weak ordering, returning an int causes undefined behavior and leads to incorrect or empty results when filtering operations by dialect.

Proposed fix:

// lower_bound comparator
[](const RegisteredOperationName &lhs, StringRef dialectName) {
  return lhs.getDialect().getNamespace() < dialectName;
}

// upper_bound comparator
[](StringRef dialectName, const RegisteredOperationName &rhs) {
  return dialectName < rhs.getDialect().getNamespace();
}

[whytolearn]

Hi, I'd like to work on this issue.