stdir is a new general-purpose dialect for MLIR that introduces a modern type system and reusable operations for building compilers and domain-specific languages (DSLs).

Note: This is not the deprecated Standard dialect. stdir is built from scratch using modern MLIR design principles. It is extensible, type-rich, and designed to lower cleanly to existing MLIR dialects.

• Provide a standardized, modern type system for MLIR
• Define a core set of reusable operations: control flow, arithmetic, tensors, memory, etc.
• Support lowering to existing dialects like SCF, Arith, LLVM, and others
• Enable Python integration for machine learning workflows and compiler tooling

The stdir dialect includes a wide range of types:

• Scalars: iN, fN, bool
• Tensors: shaped and shape-polymorphic
• Vectors: parametric width and element types
• Structs: named, nested fields
• Tuples: positional types
• Optionals: null-safe values
• Generic Containers: arrays, maps, sets
• Parametric & Opaque Types: for abstraction and generality

Basic reusable operations provided by the dialect include:

• Control Flow: stdir.if, stdir.for, stdir.while

• Arithmetic: stdir.add, stdir.sub, stdir.mul, stdir.div

• Memory Management: stdir.alloc, stdir.load, stdir.store

• Asynchronous Execution: stdir.async_execute, stdir.await

• Utilities: stdir.print, stdir.assert, stdir.cast

stdir is designed to lower to a wide range of existing MLIR dialects:

• SCF, CF – structured and conventional control flow
• Arith, Math – scalar and numeric operations
• Tensor, MemRef – data structure manipulation
• Linalg, Vector – loop nests, matrix ops, and vectorization
• Async – asynchronous and concurrent execution
• LLVM – low-level backend lowering
• PDL, PDLInterp – pattern-driven transformations