llvm/mlir
River Riddle 3fb3927bd3 [mlir] Add a new "Pattern Descriptor Language" (PDL) dialect.
PDL presents a high level abstraction for the rewrite pattern infrastructure available in MLIR. This abstraction allows for representing patterns transforming MLIR, as MLIR. This allows for applying all of the benefits that the general MLIR infrastructure provides, to the infrastructure itself. This means that pattern matching can be more easily verified for correctness, targeted by frontends, and optimized.

PDL abstracts over various different aspects of patterns and core MLIR data structures. Patterns are specified via a `pdl.pattern` operation. These operations contain a region body for the "matcher" code, and terminate with a `pdl.rewrite` that either dispatches to an external rewriter or contains a region for the rewrite specified via `pdl`. The types of values in `pdl` are handle types to MLIR C++ types, with `!pdl.attribute`, `!pdl.operation`, and `!pdl.type` directly mapping to `mlir::Attribute`, `mlir::Operation*`, and `mlir::Value` respectively.

An example pattern is shown below:

```mlir
// pdl.pattern contains metadata similarly to a `RewritePattern`.
pdl.pattern : benefit(1) {
  // External input operand values are specified via `pdl.input` operations.
  // Result types are constrainted via `pdl.type` operations.

  %resultType = pdl.type
  %inputOperand = pdl.input
  %root, %results = pdl.operation "foo.op"(%inputOperand) -> %resultType
  pdl.rewrite(%root) {
    pdl.replace %root with (%inputOperand)
  }
}
```

This is a culmination of the work originally discussed here: https://groups.google.com/a/tensorflow.org/g/mlir/c/j_bn74ByxlQ

Differential Revision: https://reviews.llvm.org/D84578
2020-08-19 13:13:06 -07:00
..
cmake/modules [mlir] Make mlir_check_link_libraries() work with interface libraries 2020-08-14 11:39:04 -07:00
docs [mlir] expose standard attributes to C API 2020-08-19 18:50:19 +02:00
examples Separate the Registration from Loading dialects in the Context 2020-08-19 01:19:03 +00:00
include [mlir] Add a new "Pattern Descriptor Language" (PDL) dialect. 2020-08-19 13:13:06 -07:00
integration_test [mlir] [VectorOps] Add masked load/store operations to Vector dialect 2020-08-05 16:45:24 -07:00
lib [mlir] Add a new "Pattern Descriptor Language" (PDL) dialect. 2020-08-19 13:13:06 -07:00
test [mlir] Add a new "Pattern Descriptor Language" (PDL) dialect. 2020-08-19 13:13:06 -07:00
tools [mlir] Add a new "Pattern Descriptor Language" (PDL) dialect. 2020-08-19 13:13:06 -07:00
unittests Separate the Registration from Loading dialects in the Context 2020-08-19 01:19:03 +00:00
utils [mlir][NFC] Remove usernames and google bug numbers from TODO comments. 2020-07-07 01:40:52 -07:00
.clang-format
.clang-tidy
CMakeLists.txt [mlir] Initial version of C APIs 2020-08-05 15:04:08 +02:00
LICENSE.TXT
README.md

Multi-Level Intermediate Representation

See https://mlir.llvm.org/ for more information.