Propagate NPU2=1 into lit subprocesses on Strix (#3128)

Co-authored-by: Claude Opus 4 (1M context) <noreply@anthropic.com>

Author: hunhoffe

programming_examples/lit.cfg.py

@@ -62,6 +62,7 @@
     config.xrt_include_dir,
     config.xrt_bin_dir,
     config.aie_src_root,
+    llvm_config,
     config.vitis_components,
 )
 

programming_guide/lit.cfg.py

@@ -44,6 +44,7 @@
     config.xrt_include_dir,
     config.xrt_bin_dir,
     config.aie_src_root,
+    llvm_config,
     config.vitis_components,
 )
 

python/aie_lit_utils/lit_config_helpers.py

@@ -256,6 +256,7 @@ def detect_xrt(
         xrt_include_dir: str,
         xrt_bin_dir: str,
         aie_src_root: str,
+        llvm_config,
         vitis_components: Optional[List[str]] = None,
     ) -> HardwareConfig:
         """
@@ -409,6 +410,7 @@ def detect_xrt(
                         )
                         config.features.extend(["ryzen_ai", "ryzen_ai_npu2"])
                         config.substitutions["%run_on_npu2%"] = run_on_npu2
+                        llvm_config.with_environment("NPU2", "1")
                         logger.info(
                             "Running tests on NPU2 with command line: %s", run_on_npu2
                         )

test/lit.cfg.py

@@ -70,6 +70,7 @@
     config.xrt_include_dir,
     config.xrt_bin_dir,
     config.aie_src_root,
+    llvm_config,
     config.vitis_components,
 )
 

test/npu-xrt/verify_npu2_env/run.lit

@@ -0,0 +1,11 @@
+// (c) Copyright 2026 Advanced Micro Devices, Inc.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// Regression: NPU2=1 must propagate from lit into test subprocesses on Strix
+// so Makefile-driven examples whose devicename defaults to
+// `$(if $(filter 1,$(NPU2)),npu2,npu)` pick the AIE2P target.
+//
+// REQUIRES: ryzen_ai_npu2
+//
+// RUN: %python -c "import os; print('NPU2=' + os.environ.get('NPU2','<unset>'))" | FileCheck %s
+// CHECK: NPU2=1