[Mlir-commits] [mlir] [mlir][PDL] Add support for native constraints with results (PR #82760)

[Martin Paul Lücke]

================
@@ -79,6 +79,57 @@ module @constraints {
 
 // -----
 
+// CHECK-LABEL: module @constraint_with_result
+module @constraint_with_result {
+  // CHECK: func @matcher(%[[ROOT:.*]]: !pdl.operation)
+  // CHECK: %[[ATTR:.*]] = pdl_interp.apply_constraint "check_op_and_get_attr_constr"(%[[ROOT]]
+  // CHECK: pdl_interp.record_match @rewriters::@pdl_generated_rewriter(%[[ROOT]], %[[ATTR]] : !pdl.operation, !pdl.attribute)
+  pdl.pattern : benefit(1) {
+    %root = operation
+    %attr = pdl.apply_native_constraint "check_op_and_get_attr_constr"(%root : !pdl.operation) : !pdl.attribute
+    rewrite %root with "rewriter"(%attr : !pdl.attribute)
+  }
+}
+
+// -----
+
+// CHECK-LABEL: module @constraint_with_unused_result
+module @constraint_with_unused_result {
+  // CHECK: func @matcher(%[[ROOT:.*]]: !pdl.operation)
+  // CHECK: %[[ATTR:.*]] = pdl_interp.apply_constraint "check_op_and_get_attr_constr"(%[[ROOT]]
+  // CHECK: pdl_interp.record_match @rewriters::@pdl_generated_rewriter(%[[ROOT]] : !pdl.operation)
+  pdl.pattern : benefit(1) {
+    %root = operation
+    %attr = pdl.apply_native_constraint "check_op_and_get_attr_constr"(%root : !pdl.operation) : !pdl.attribute
+    rewrite %root with "rewriter"
+  }
+}
+
+// -----
+
+// CHECK-LABEL: module @constraint_with_result_multiple
+module @constraint_with_result_multiple {
+  // check that native constraints work as expected even when multiple identical constraints are fused
+
+  // CHECK: func @matcher(%[[ROOT:.*]]: !pdl.operation)
+  // CHECK: %[[ATTR:.*]] = pdl_interp.apply_constraint "check_op_and_get_attr_constr"(%[[ROOT]]
+  // CHECK-NOT: pdl_interp.apply_constraint "check_op_and_get_attr_constr"
+  // CHECK: pdl_interp.record_match @rewriters::@pdl_generated_rewriter_0(%[[ROOT]], %[[ATTR]]  : !pdl.operation, !pdl.attribute)
+  // CHECK: pdl_interp.record_match @rewriters::@pdl_generated_rewriter(%[[ROOT]], %[[ATTR]] : !pdl.operation, !pdl.attribute)
+  pdl.pattern : benefit(1) {
+    %root = operation
+    %attr = pdl.apply_native_constraint "check_op_and_get_attr_constr"(%root : !pdl.operation) : !pdl.attribute
+    rewrite %root with "rewriter"(%attr : !pdl.attribute)
+  }
+  pdl.pattern : benefit(1) {
+    %root = operation
+    %attr = pdl.apply_native_constraint "check_op_and_get_attr_constr"(%root : !pdl.operation) : !pdl.attribute
+    rewrite %root with "rewriter"(%attr : !pdl.attribute)
+  }
+}
+
+// -----
+
----------------
martin-luecke wrote:

As @Mogball suggested on the initial patch: Please add a test that uses the result of `pdl.apply_native_constraint` on the matching side of the pattern.

Something along the lines of:
```
  pdl.pattern : benefit(1) {
    %inputOp = operation
    %result = result 0 of %inputOp
    %attr = pdl.apply_native_constraint "check_op_and_get_attr_constr"(%inputOp : !pdl.operation) : !pdl.attribute
    %root = operation(%result : !pdl.value) {"attr" = %attr}
    rewrite %root with "rewriter"(%attr : !pdl.attribute)
  }
```

https://github.com/llvm/llvm-project/pull/82760