fix: port moe routing to new triton_kernels API

The `triton_kernels.routing` module was deprecated and removed in triton
commit 30ede52aa (triton-lang/triton#8375).

Replaced deprecated `routing()` call with new primitives in
`compute_routing()`.

---

Upgrade to `triton>=3.5`. `triton_kernels` HEAD uses on
`tl.target_info()` that is not available in 3.4.

Author: tom-pollak

gpt_oss/triton/moe.py

@@ -5,10 +5,10 @@
 import triton_kernels.swiglu
 from triton_kernels.numerics_details.mxfp import downcast_to_mxfp
 from triton_kernels.matmul_ogs import PrecisionConfig, FlexCtx, FnSpecs, FusedActivation
-from triton_kernels.matmul_ogs import matmul_ogs
+from triton_kernels.matmul_ogs import matmul_ogs, RoutingData, GatherIndx, ScatterIndx
 from triton_kernels.numerics import InFlexData
-from triton_kernels.routing import routing
-from triton_kernels.tensor import convert_layout
+from triton_kernels.topk import topk
+from triton_kernels.tensor import convert_layout, make_ragged_tensor_metadata
 from triton_kernels.tensor_details.layout import StridedLayout, HopperMXScaleLayout, HopperMXValueLayout
 from triton_kernels.tensor import wrap_torch_tensor, FP4
 
@@ -31,6 +31,32 @@ def swiglu(x, alpha: float = 1.702, limit: float = 7.0, interleaved: bool = True
     return out_glu * (x_linear + 1)
 
 
+def compute_routing(logits, n_expts_act, n_expts_tot):
+    sparse_logits = topk(logits, n_expts_act, apply_softmax=True)
+
+    dispatch_indx = sparse_logits.mask_metadata.col_sorted_indx
+    combine_indx = sparse_logits.mask_metadata.row_sorted_indx
+
+    ragged_batch_metadata = make_ragged_tensor_metadata(
+        sparse_logits.mask_metadata.col_sum,
+        dispatch_indx.shape[0]
+    )
+
+    gate_scal = sparse_logits.vals.flatten()[combine_indx]
+
+    rdata = RoutingData(
+        gate_scal,
+        ragged_batch_metadata.batch_sizes,
+        n_expts_tot,
+        n_expts_act,
+        ragged_batch_metadata
+    )
+    gather_indx = GatherIndx(combine_indx, dispatch_indx)
+    scatter_indx = ScatterIndx(dispatch_indx, combine_indx)
+
+    return rdata, gather_indx, scatter_indx
+
+
 def moe(x, wg, w1, w1_mx, w2, w2_mx, bg, b1, b2, experts_per_token=4, num_experts=128, swiglu_limit=7.0, fused_act=True, interleaved=True):
     if x.numel() == 0:
         return x
@@ -41,8 +67,9 @@ def moe(x, wg, w1, w1_mx, w2, w2_mx, bg, b1, b2, experts_per_token=4, num_expert
 
     with record_function("wg"):
         logits = matmul_ogs(x, wg, bg, precision_config=pcg)
+
     with record_function("routing"):
-        rdata, gather_indx, scatter_indx = routing(logits, experts_per_token, simulated_ep=1)
+        rdata, gather_indx, scatter_indx = compute_routing(logits, experts_per_token, num_experts)
 
     if fused_act:
         assert interleaved, "Fused activation requires interleaved weights"

pyproject.toml

@@ -24,7 +24,7 @@ requires-python = ">=3.12"
 version = "0.0.8"
 
 [project.optional-dependencies]
-triton = ["triton>=3.4", "safetensors>=0.5.3", "torch>=2.7.0"]
+triton = ["triton>=3.5", "safetensors>=0.5.3", "torch>=2.7.0"]
 torch = ["safetensors>=0.5.3", "torch>=2.7.0"]
 metal = ["numpy", "tqdm", "safetensors", "torch"]
 test = ["pytest>=8.4.1", "httpx>=0.28.1"]