interpreter: (pdl) add test for result matching

tests/interpreters/test_pdl_interpreter.py

@@ -12,7 +12,7 @@
 )
 from xdsl.interpreter import Interpreter
 from xdsl.interpreters.pdl import PDLMatcher, PDLRewriteFunctions, PDLRewritePattern
-from xdsl.ir import Attribute
+from xdsl.ir import Attribute, Block
 from xdsl.pattern_rewriter import PatternRewriteWalker
 from xdsl.utils.test_value import TestSSAValue
 
@@ -148,6 +148,89 @@ def test_match_operand():
     assert matcher.matching_context == {ssa_value: xdsl_value}
 
 
+def test_match_result():
+    matcher = PDLMatcher()
+
+    type_op = pdl.TypeOp(IntegerType(32))
+    operation_op = pdl.OperationOp(op_name=None, type_values=(type_op.result,))
+    result_op = pdl.ResultOp(0, operation_op.op)
+    xdsl_op = test.TestOp(result_types=(i32,))
+    xdsl_value = xdsl_op.res[0]
+
+    # New result
+    # If the result of an operation has the expected type we should match
+    assert matcher.match_result(result_op.val, result_op, xdsl_value)
+    assert matcher.matching_context == {
+        result_op.val: xdsl_value,
+        operation_op.op: xdsl_op,
+        type_op.result: i32,
+    }
+
+    # Same result
+    # We should accept the same value given the same constraint
+    assert matcher.match_result(result_op.val, result_op, xdsl_value)
+    assert matcher.matching_context == {
+        result_op.val: xdsl_value,
+        operation_op.op: xdsl_op,
+        type_op.result: i32,
+    }
+
+    # Other result
+    # We should not match again with a different value, even if it has the correct type
+    other_xdsl_op = test.TestOp(result_types=(i32,))
+    other_xdsl_value = other_xdsl_op.res[0]
+
+    assert not matcher.match_result(result_op.val, result_op, other_xdsl_value)
+    assert matcher.matching_context == {
+        result_op.val: xdsl_value,
+        operation_op.op: xdsl_op,
+        type_op.result: i32,
+    }
+
+    # Wrong type
+    # Matching should fail if the result's type differs from the expected type
+    wrong_type_op = pdl.TypeOp(i64)
+    wrong_type_operation_op = pdl.OperationOp(
+        op_name=None, type_values=(wrong_type_op.result,)
+    )
+    wrong_type_result_op = pdl.ResultOp(0, wrong_type_operation_op.op)
+
+    assert not matcher.match_result(
+        wrong_type_result_op.val, wrong_type_result_op, xdsl_value
+    )
+    assert matcher.matching_context == {
+        result_op.val: xdsl_value,
+        operation_op.op: xdsl_op,
+        type_op.result: i32,
+    }
+
+    # Index out of range
+    # If the operation has only one result, we should not match results at different
+    # indices
+    out_of_range_result_op = pdl.ResultOp(1, operation_op.op)
+    assert not matcher.match_result(
+        out_of_range_result_op.val, out_of_range_result_op, xdsl_value
+    )
+    assert matcher.matching_context == {
+        result_op.val: xdsl_value,
+        operation_op.op: xdsl_op,
+        type_op.result: i32,
+    }
+
+    # Block argument
+    # Result patterns should not match on block arguments
+    block = Block(arg_types=(i32,))
+    block_arg_result_op = pdl.ResultOp(1, operation_op.op)
+    assert not matcher.match_result(
+        block_arg_result_op.val, block_arg_result_op, block.args[0]
+    )
+    assert matcher.matching_context == {
+        result_op.val: xdsl_value,
+        operation_op.op: xdsl_op,
+        type_op.result: i32,
+    }
+
+
 def test_native_constraint_constant_parameter():
     """
     Check that `pdl.apply_native_constraint` can take constant attribute parameters