feat(ascend): add deterministic collective Ascend C kernel

csrc/ascend/batch_invariant_logp_ascend.asc

@@ -307,10 +307,3 @@ std::vector<torch::Tensor> batch_invariant_logp_ascend_forward(torch::Tensor log
     }
     return {logp, lse};
 }
-
-PYBIND11_MODULE(TORCH_EXTENSION_NAME, m)
-{
-    m.def("batch_invariant_logp_ascend",
-          &batch_invariant_logp_ascend_forward,
-          "Batch-invariant selected-token log-probability (Ascend C forward)");
-}

csrc/ascend/ops_npu.asc

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (c) 2026 RL-Kernel Contributors
+
+// Single Python module entry point for the unified Ascend C extension.
+// Keep PYBIND11_MODULE in one translation unit as new .asc kernels are added.
+
+#include <vector>
+
+#include <torch/extension.h>
+
+std::vector<torch::Tensor> batch_invariant_logp_ascend_forward(
+    torch::Tensor logits, torch::Tensor target, int64_t ignore_index);
+
+int64_t deterministic_collective_create(
+    torch::Tensor staging, int64_t world_size, int64_t rank);
+void deterministic_collective_destroy(int64_t handle);
+void deterministic_collective_stage(int64_t handle, torch::Tensor input);
+void deterministic_collective_reduce(
+    int64_t handle, torch::Tensor gathered, torch::Tensor output, int64_t slice_offset);
+
+PYBIND11_MODULE(TORCH_EXTENSION_NAME, m)
+{
+    m.def("batch_invariant_logp_ascend",
+          &batch_invariant_logp_ascend_forward,
+          "Batch-invariant selected-token log-probability (Ascend C forward)");
+    m.def("deterministic_collective_create",
+          &deterministic_collective_create,
+          "Deterministic TP-invariant collective state (Ascend)");
+    m.def("deterministic_collective_destroy",
+          &deterministic_collective_destroy,
+          "Release a deterministic collective state (Ascend)");
+    m.def("deterministic_collective_stage",
+          &deterministic_collective_stage,
+          "Stage a tensor into the collective staging buffer (Ascend)");
+    m.def("deterministic_collective_reduce",
+          &deterministic_collective_reduce,
+          "Fixed-tree ordered reduction over gathered rank tensors (Ascend)");
+}

rl_engine/_C_npu.pyi

@@ -8,3 +8,16 @@ def batch_invariant_logp_ascend(
     target: torch.Tensor,
     ignore_index: int,
 ) -> list[torch.Tensor]: ...
+def deterministic_collective_create(
+    staging: torch.Tensor,
+    world_size: int,
+    rank: int,
+) -> int: ...
+def deterministic_collective_destroy(handle: int) -> None: ...
+def deterministic_collective_stage(handle: int, input: torch.Tensor) -> None: ...
+def deterministic_collective_reduce(
+    handle: int,
+    gathered: torch.Tensor,
+    output: torch.Tensor,
+    slice_offset: int,
+) -> None: ...