perf[cartesian]: avoid x + 0 and 0 + x expression in index bounds

src/gt4py/cartesian/gtc/dace/oir_to_treeir.py

@@ -238,8 +238,16 @@ def visit_While(self, node: oir.While, ctx: tir.Context) -> None:
 
     def visit_AxisBound(self, node: common.AxisBound, axis_start: str, axis_end: str) -> str:
         if node.level == common.LevelMarker.START:
+            if axis_start == "0":
+                return f"({node.offset})"
+            if node.offset == 0:
+                return f"({axis_start})"
             return f"({axis_start}) + ({node.offset})"
 
+        if axis_end == "0":
+            return f"({node.offset})"
+        if node.offset == 0:
+            return f"({axis_end})"
         return f"({axis_end}) + ({node.offset})"
 
     def visit_RuntimeAxisBound(self, node: common.RuntimeAxisBound, **kwargs: Any) -> None:

tests/cartesian_tests/unit_tests/test_gtc/dace/test_oir_to_treeir.py

@@ -0,0 +1,45 @@
+# GT4Py - GridTools Framework
+#
+# Copyright (c) 2014-2024, ETH Zurich
+# All rights reserved.
+#
+# Please, refer to the LICENSE file in the root directory.
+# SPDX-License-Identifier: BSD-3-Clause
+
+import pytest
+
+from gt4py.cartesian.gtc.dace import oir_to_treeir
+from gt4py.cartesian.gtc import common
+from gt4py.cartesian.stencil_builder import StencilBuilder
+from gt4py.cartesian.gtscript import PARALLEL, Field, computation, interval
+
+# Because "dace tests" filter by `requires_dace`, we still need to add the marker.
+# This global variable adds the marker to all test functions in this module.
+pytestmark = pytest.mark.requires_dace
+
+
+def ignore_me(field: Field[float]):  # type: ignore
+    with computation(PARALLEL), interval(...):
+        field += 1
+
+
+@pytest.mark.parametrize(
+    "node,axis_start,axis_end,expected",
+    [
+        (common.AxisBound.from_start(1), "2", "n/a", "(2) + (1)"),
+        (common.AxisBound.from_start(0), "2", "n/a", "(2)"),
+        (common.AxisBound.from_start(1), "0", "n/a", "(1)"),
+        (common.AxisBound.from_start(0), "0", "n/a", "(0)"),
+        (common.AxisBound.from_end(1), "n/a", "2", "(2) + (1)"),
+        (common.AxisBound.from_end(0), "n/a", "2", "(2)"),
+        (common.AxisBound.from_end(1), "n/a", "0", "(1)"),
+        (common.AxisBound.from_end(0), "n/a", "0", "(0)"),
+    ],
+)
+def test_visit_AxisBound(
+    node: common.AxisBound, axis_start: str, axis_end: str, expected: str
+) -> None:
+    builder = StencilBuilder(ignore_me)
+    visitor = oir_to_treeir.OIRToTreeIR(builder)
+
+    assert visitor.visit_AxisBound(node, axis_start, axis_end) == expected