This explicit tag is useful is several ways:
*) This simplifies how to mark sub sections of a dialect as explicitly unsupported, e.g. my target supports all operations in the foo dialect except for these select few. This is useful for partial lowerings between dialects.
*) Partial conversions will now verify that operations that were explicitly marked as illegal must be converted. This provides some guarantee that the operations that need to be lowered by a specific pass will be.
PiperOrigin-RevId: 258582879
Users generally want several different modes of conversion. This cl refactors DialectConversion to provide two:
* Partial (applyPartialConversion)
- This mode allows for illegal operations to exist in the IR, and does not fail if an operation fails to be legalized.
* Full (applyFullConversion)
- This mode fails if any operation is not properly legalized to the conversion target. This allows for ensuring that the IR after a conversion only contains operations legal for the target.
PiperOrigin-RevId: 258412243
During conversion, if a type conversion has dangling uses a type conversion must persist after conversion has finished to maintain valid IR. In these cases, we now query the TypeConverter to materialize a conversion for us. This allows for the default case of a full conversion to continue working as expected, but also handle the degenerate cases more robustly.
PiperOrigin-RevId: 255637171
