Refactor DRR helpers into a Utils.td file

include/DRR/BUILD

@@ -0,0 +1,16 @@
+# Tablegen helpers for declarative rewrite (DRR) patterns
+load("@llvm-project//mlir:tblgen.bzl", "td_library")
+
+package(
+    default_applicable_licenses = ["@heir//:license"],
+    default_visibility = ["//visibility:public"],
+)
+
+td_library(
+    name = "DRR",
+    srcs = [
+        "Utils.td",
+    ],
+    # include from the heir-root to enable fully-qualified include-paths
+    includes = ["../../.."],
+)

include/DRR/Utils.td

@@ -0,0 +1,27 @@
+
+include "mlir/Dialect/Arith/IR/ArithOps.td"
+include "mlir/IR/EnumAttr.td"
+include "mlir/IR/PatternBase.td"
+
+// When using DRR to define new artih ops, one must include an attribute
+// describing the overflow semantics. When the new arith op is built from an
+// existing op, one should match the overflow attribute and propagate it, but
+// when the op is built from scratch, one needs to pass an overflow choice, and
+// if there is no reason to pick a particular overflow type, use this helper as
+// a default.
+defvar DefOverflow = ConstantEnumCase<Arith_IntegerOverflowAttr, "none">;
+
+// When constructing a new variadic op, and you want to pass it a single argument
+// as its variadic input, use this helper. To understand why this is needed, see
+// https://discourse.llvm.org/t/compilation-failure-with-drr-generated-pattern/77385
+def MakeSingleResultVariadic: NativeCodeCall<"{ $0 }">;
+
+// Determine if an input integer attr is zero
+def IsZeroIntAttr :
+    Constraint<
+      CPred<"llvm::cast<mlir::IntegerAttr>($0).getValue().isZero()">>;
+
+// Construct an index.cast op, which is necessary here because the default
+// builder is not compatible with DRR as of 2024-03-11.
+def CreateIndexCastOp : NativeCodeCall<
+      "$_builder.create<arith::IndexCastOp>($0.getLoc(), $1.getType(), $0)">;

include/Dialect/TensorExt/IR/BUILD

@@ -25,6 +25,7 @@ td_library(
     # include from the heir-root to enable fully-qualified include-paths
     includes = ["../../../.."],
     deps = [
+        "@heir//include/DRR",
         "@llvm-project//mlir:BuiltinDialectTdFiles",
         "@llvm-project//mlir:InferTypeOpInterfaceTdFiles",
         "@llvm-project//mlir:OpBaseTdFiles",

include/Dialect/TensorExt/IR/TensorExtCanonicalization.td

@@ -2,22 +2,11 @@
 #define INCLUDE_DIALECT_TENSOREXT_IR_TENSOREXTCANONICALIZATION_TD_
 
 include "TensorExtOps.td"
+include "include/DRR/Utils.td"
 include "mlir/Dialect/Arith/IR/ArithOps.td"
 include "mlir/Dialect/Tensor/IR/TensorOps.td"
 include "mlir/IR/PatternBase.td"
 
-// TODO(#515): refactor these helpers to a common file with InsertRotate.td
-defvar DefOverflow = ConstantEnumCase<Arith_IntegerOverflowAttr, "none">;
-
-def MakeSingleResultVariadic: NativeCodeCall<"{ $0 }">;
-
-def CreateIndexCastOp : NativeCodeCall<
-      "$_builder.create<arith::IndexCastOp>($0.getLoc(), $1.getType(), $0)">;
-
-def IsZero :
-    Constraint<
-      CPred<"llvm::cast<mlir::IntegerAttr>($0).getValue().isZero()">>;
-
 def OutOfBoundsOfTensorDim :
   Constraint<
     CPred<
@@ -31,7 +20,7 @@ def OutOfBoundsOfTensorDim :
 def DropZeroRotation : Pat<
   (TensorExt_RotateOp $tensor, (ConstantLikeMatcher APIntAttr:$c0)),
   (replaceWithValue $tensor),
-  [(IsZero $c0)]
+  [(IsZeroIntAttr $c0)]
 >;
 
 // rotate %t, x -> rotate %t, x mod size

include/Dialect/TensorExt/Transforms/BUILD

@@ -41,6 +41,7 @@ gentbl_cc_library(
     tblgen = "@llvm-project//mlir:mlir-tblgen",
     td_file = "InsertRotate.td",
     deps = [
+        "@heir//include/DRR",
         "@heir//include/Dialect/TensorExt/IR:ops_inc_gen",
         "@heir//include/Dialect/TensorExt/IR:td_files",
         "@llvm-project//mlir:ArithOpsTdFiles",

include/Dialect/TensorExt/Transforms/InsertRotate.td

@@ -1,6 +1,7 @@
 #ifndef INCLUDE_DIALECT_TENSOREXT_IR_TENSOREXTPATTERNS_TD_
 #define INCLUDE_DIALECT_TENSOREXT_IR_TENSOREXTPATTERNS_TD_
 
+include "include/DRR/Utils.td"
 include "include/Dialect/TensorExt/IR/TensorExtOps.td"
 include "mlir/Dialect/Arith/IR/ArithOps.td"
 include "mlir/Dialect/Tensor/IR/TensorOps.td"
@@ -13,12 +14,6 @@ include "mlir/IR/PatternBase.td"
 // https://arxiv.org/abs/2202.01649 and the hir2hir passes in
 // https://github.com/MarbleHE/HECO/blob/main/src/Passes/hir2hir/
 
-defvar DefOverflow = ConstantEnumCase<Arith_IntegerOverflowAttr, "none">;
-
-// To understand why this is needed, see
-// https://discourse.llvm.org/t/compilation-failure-with-drr-generated-pattern/77385
-def MakeSingleResultVariadic: NativeCodeCall<"{ $0 }">;
-
 // Match an arith op that extracts scalar values from two tensors, and replace
 // it with rotations to align slots and apply the same op in SIMD. Other
 // patterns in this file will find better alignment of adjacent rotations, and