Add recommender model compile coverage

crates/luminal_cuda_lite/examples/egglog_saturation.rs

@@ -231,9 +231,7 @@ fn build_qwen_moe(cx: &mut Graph) -> GraphTensor {
         .unsqueeze(2)
         .matmul(down_gathered.transpose(2, 3))
         .squeeze(2);
-    let mut weights_exp = top_k_values.unsqueeze(top_k_values.dims().len());
-    weights_exp.shape.expand(down_out.dims());
-    (down_out * weights_exp).sum(n - 1)
+    (down_out * top_k_values.unsqueeze(top_k_values.dims().len())).sum(n - 1)
 }
 
 fn build_gemma_moe(cx: &mut Graph) -> GraphTensor {
@@ -280,9 +278,7 @@ fn build_gemma_moe(cx: &mut Graph) -> GraphTensor {
         .unsqueeze(2)
         .matmul(down_gathered.transpose(2, 3))
         .squeeze(2);
-    let mut weights_exp = top_k_weights.unsqueeze(top_k_weights.dims().len());
-    weights_exp.shape.expand(down_out.dims());
-    (down_out * weights_exp).sum(n - 1)
+    (down_out * top_k_weights.unsqueeze(top_k_weights.dims().len())).sum(n - 1)
 }
 
 fn gather_experts(

crates/luminal_cuda_lite/src/dyn_backend.rs

@@ -5,6 +5,7 @@ use luminal::dyn_backend::{BackendCompileArgs, DynBackend, compile_backend};
 use luminal::prelude::*;
 
 use crate::cudarc::driver::CudaContext;
+use crate::host::describe_host_op;
 use crate::runtime::CudaRuntime;
 
 /// [`DynBackend`] wrapper for [`CudaRuntime`].
@@ -39,6 +40,26 @@ impl DynBackend for CudaLiteDynBackend {
         self.runtime.execute(dyn_map);
     }
 
+    fn kernel_names(&self) -> Vec<String> {
+        self.runtime
+            .kernel_names()
+            .iter()
+            .map(|name| (*name).to_string())
+            .collect()
+    }
+
+    fn host_op_names(&self) -> Vec<String> {
+        self.runtime
+            .host_ops()
+            .iter()
+            .map(|op| describe_host_op(*op))
+            .collect()
+    }
+
+    fn print_execution_stats(&self) {
+        self.runtime.print_execution_stats();
+    }
+
     fn supports_device_ptrs(&self) -> bool {
         true
     }

crates/luminal_cuda_lite/src/host/cublas/mod.rs

@@ -247,6 +247,10 @@ impl HostOp for CuBlasSgemmV2 {
         Ok(())
     }
 
+    fn stats_name(&self) -> Option<&'static str> {
+        Some("CuBlasSgemmV2")
+    }
+
     fn output_size(&self) -> Expression {
         self.m * self.n
     }

crates/luminal_cuda_lite/src/host/cublaslt/mod.rs

@@ -419,7 +419,6 @@ fn transpose_op_name(op: cublasOperation_t) -> &'static str {
     }
 }
 
-#[cfg(test)]
 fn epilogue_name(epilogue: cublasLtEpilogue_t) -> &'static str {
     match epilogue {
         cublasLtEpilogue_t::CUBLASLT_EPILOGUE_DEFAULT => "DEFAULT",
@@ -978,6 +977,18 @@ impl CuBlasLt {
             && normalize(self.stride_c) == normalize(self.stride_d)
             && self.c_order == self.d_order
     }
+
+    pub(crate) fn debug_summary(&self) -> String {
+        let resolve = |e: &Expression| -> Expression { e.substitute('z', Expression::from(1)) };
+        format!(
+            "CuBlasLt[m={}, n={}, k={}, batch={}, epilogue={}]",
+            resolve(&self.m),
+            resolve(&self.n),
+            resolve(&self.k),
+            resolve(&self.batch_count),
+            epilogue_name(self.epilogue),
+        )
+    }
 }
 
 impl HostOp for CuBlasLt {
@@ -1114,6 +1125,10 @@ impl HostOp for CuBlasLt {
         Ok(())
     }
 
+    fn stats_name(&self) -> Option<&'static str> {
+        Some("CuBlasLt")
+    }
+
     fn output_size(&self) -> Expression {
         let resolve = |e: &Expression| -> Expression { e.substitute('z', Expression::from(1)) };
         resolve(&self.batch_count) * resolve(&self.m) * resolve(&self.n)

crates/luminal_cuda_lite/src/host/mod.rs

@@ -1,6 +1,7 @@
 use std::{fmt::Debug, sync::Arc};
 
 use crate::cudarc::driver::{CudaStream, DriverError, result};
+use crate::kernel::CudaGraphOp;
 use luminal::{op::EgglogOp, prelude::*};
 pub mod compute_attn_mask;
 mod cublas;
@@ -79,6 +80,24 @@ pub(crate) fn cublaslt_c_d_layouts_match(op: &dyn HostOp) -> Option<bool> {
         .map(cublaslt::CuBlasLt::c_d_layouts_match)
 }
 
+pub(crate) fn describe_host_op(op: &dyn HostOp) -> String {
+    if let Some(op) = op.as_any().downcast_ref::<cublaslt::CuBlasLt>() {
+        return op.debug_summary();
+    }
+    if let Some(op) = op.as_any().downcast_ref::<CudaGraphOp>() {
+        let mut summary = op.debug_summary();
+        if std::env::var_os("LUMINAL_PROFILE_CUDA_GRAPH").is_some()
+            && let Some(timing) = op.debug_timing_summary()
+        {
+            summary.push_str(" [");
+            summary.push_str(&timing);
+            summary.push(']');
+        }
+        return summary;
+    }
+    op.stats_name().unwrap_or("unknown").to_string()
+}
+
 /// Non-owning device buffer handle used by host operations.
 ///
 /// Runtime-owned intermediates may be a whole `CudaSlice`, a subregion inside

crates/luminal_cuda_lite/src/kernel/hlir.rs

@@ -12,7 +12,10 @@ use luminal::{
         base::{DTYPE, ELIST, EXPRESSION, F64, OP_KIND, SORTS, dtype, ilist, op_term},
         extract_dtype, extract_expr, extract_expr_list,
     },
-    hlir::{Add, Exp2, LessThan, Log2, MaxReduce, Mod, Mul, Recip, Scatter, Sin, Sqrt, SumReduce},
+    hlir::{
+        Add, Concat2D, EmbeddingBagSum, Exp2, LessThan, Log2, MaxReduce, Mod, Mul, Recip, Scatter,
+        Sin, Sqrt, SumReduce,
+    },
     op::*,
     prelude::*,
 };
@@ -65,6 +68,8 @@ pub type Ops = (
     KernelConstant,
     KernelCast,
     KernelEmbed,
+    KernelConcat2D,
+    KernelEmbeddingBagSum,
 );
 
 /// Build a rewrite that matches an HLIR op, reads dtype(s) from the given source fields,
@@ -1540,22 +1545,19 @@ impl KernelOp for KernelIota {
         Expression,
         FxHashMap<char, CudaSlice<u8>>,
     ) {
-        let mut vars = self.expr.dyn_vars().into_iter().collect::<FxHashSet<_>>();
-        vars.extend(self.range.dyn_vars());
+        let vars = self.expr.dyn_vars().into_iter().collect::<FxHashSet<_>>();
         let (dyn_defines, _sorted_dims) = generate_dyn_dims_defines(&vars);
         let dyn_dims_param = if vars.is_empty() {
             ""
         } else {
             ", const int* dyn_dims"
         };
-        let range = self.range.to_kernel();
         let kernel = format!(
             "
 {dyn_defines}
 extern \"C\" {{
     __global__ void iota_k(int *C{dyn_dims_param}) {{
         long long const_z = (long long)blockIdx.x * blockDim.x + threadIdx.x;
-        if (const_z >= {range}) return;
         C[const_z] = {};
     }}
 }}",
@@ -1574,8 +1576,8 @@ extern \"C\" {{
             func,
             module,
             kernel,
-            (self.range.ceil_div(256), 1.into(), 1.into()),
-            (256.into(), 1.into(), 1.into()),
+            (self.range, 1.into(), 1.into()),
+            (1.into(), 1.into(), 1.into()),
             0.into(),
             FxHashMap::default(),
         )
@@ -2938,14 +2940,6 @@ impl KernelOp for KernelCast {
     ) {
         let out_dtype = cuda_dtype(self.out_dtype);
         let includes = dtype_includes(&[self.in_dtype, self.out_dtype]);
-        let vars = self.size.dyn_vars().into_iter().collect::<FxHashSet<_>>();
-        let (dyn_defines, _sorted_dims) = generate_dyn_dims_defines(&vars);
-        let dyn_dims_param = if vars.is_empty() {
-            ""
-        } else {
-            ", const int* dyn_dims"
-        };
-        let size = self.size.to_kernel();
 
         let kernel = if self.in_dtype.bits() < 8 {
             // Sub-byte packed types: multiple values packed per byte.
@@ -2955,11 +2949,9 @@ impl KernelOp for KernelCast {
             let mask = (1u32 << bits) - 1;
             format!(
                 "{includes}
-{dyn_defines}
 extern \"C\" {{
-    __global__ void cast_k({out_dtype} *out, const unsigned char *in_raw{dyn_dims_param}) {{
+    __global__ void cast_k({out_dtype} *out, const unsigned char *in_raw) {{
         long long idx = (long long)blockIdx.x * blockDim.x + threadIdx.x;
-        if (idx >= {size}) return;
         long long bit_offset = idx * {bits};
         long long byte_idx = bit_offset >> 3;
         int bit_pos = (int)(bit_offset & 7);
@@ -2975,11 +2967,9 @@ extern \"C\" {{
             let in_dtype = cuda_dtype(self.in_dtype);
             format!(
                 "{includes}
-{dyn_defines}
 extern \"C\" {{
-    __global__ void cast_k({out_dtype} *out, const {in_dtype} *in{dyn_dims_param}) {{
+    __global__ void cast_k({out_dtype} *out, const {in_dtype} *in) {{
         long long const_z = (long long)blockIdx.x * blockDim.x + threadIdx.x;
-        if (const_z >= {size}) return;
         out[const_z] = ({out_dtype})in[const_z];
     }}
 }}"
@@ -2998,8 +2988,8 @@ extern \"C\" {{
             func,
             module,
             kernel,
-            (self.size.ceil_div(256), 1.into(), 1.into()),
-            (256.into(), 1.into(), 1.into()),
+            (self.size, 1.into(), 1.into()),
+            (1.into(), 1.into(), 1.into()),
             0.into(),
             FxHashMap::default(),
         )
@@ -3290,15 +3280,12 @@ impl KernelOp for KernelEmbed {
         let token_offset_expr = flatten_strides(&self.batch_shape, &self.token_stride).to_kernel();
         let out_offset_expr = flatten_strides(&self.batch_shape, &self.out_stride).to_kernel();
         let embed_dim_expr = self.embed_dim.to_kernel();
-        let total_threads = batch_size * self.embed_dim;
-        let n_elements = total_threads.to_kernel();
         let kernel = format!(
             "
 {dyn_defines}
 extern \"C\" {{
     __global__ void embed(float *out, const int *token_ids, const float *embed_table{dyn_dims_param}) {{
         long long idx = (long long)blockIdx.x * blockDim.x + threadIdx.x;
-        if (idx >= {n_elements}) return;
         long long embed_dim = {embed_dim_expr};
         long long batch_idx = idx / embed_dim;
         long long embed_idx = idx % embed_dim;
@@ -3321,12 +3308,13 @@ extern \"C\" {{
         };
         // Return empty constants map - we now use shared dyn_dims buffer
         let constants = FxHashMap::default();
+        let total_threads = batch_size * self.embed_dim;
         (
             func,
             module,
             kernel,
-            (total_threads.ceil_div(256), 1.into(), 1.into()),
-            (256.into(), 1.into(), 1.into()),
+            (total_threads, 1.into(), 1.into()),
+            (1.into(), 1.into(), 1.into()),
             0.into(),
             constants,
         )
@@ -3371,3 +3359,361 @@ extern \"C\" {{
         "Embed"
     }
 }
+
+#[derive(Default, Debug, Clone)]
+pub struct KernelEmbeddingBagSum {
+    n_bags: Expression,
+    n_indices: Expression,
+    hidden_dim: Expression,
+    num_embeddings: Expression,
+    dtype: DType,
+}
+
+impl EgglogOp for KernelEmbeddingBagSum {
+    fn sort(&self) -> SortDef {
+        sort(
+            OP_KIND,
+            "KernelEmbeddingBagSum",
+            &[
+                ("n_bags", EXPRESSION),
+                ("n_indices", EXPRESSION),
+                ("hidden_dim", EXPRESSION),
+                ("num_embeddings", EXPRESSION),
+                ("dtype", DTYPE),
+            ],
+        )
+    }
+
+    fn n_inputs(&self) -> usize {
+        3
+    }
+
+    fn rewrites(&self) -> Vec<Rule> {
+        vec![kernel_rewrite::<EmbeddingBagSum, Self>()]
+    }
+
+    fn cleanup(&self) -> bool {
+        false
+    }
+
+    fn extract<'a>(
+        &'a self,
+        egraph: &'a SerializedEGraph,
+        kind_children: &[&'a ENodeId],
+        input_enodes: Vec<&'a ENodeId>,
+        _list_cache: &mut FxHashMap<&'a ENodeId, Vec<Expression>>,
+        expr_cache: &mut FxHashMap<&'a ENodeId, Expression>,
+    ) -> (LLIROp, Vec<&'a ENodeId>) {
+        (
+            LLIROp::new::<dyn KernelOp>(Box::new(Self {
+                n_bags: extract_expr(egraph, kind_children[0], expr_cache).unwrap(),
+                n_indices: extract_expr(egraph, kind_children[1], expr_cache).unwrap(),
+                hidden_dim: extract_expr(egraph, kind_children[2], expr_cache).unwrap(),
+                num_embeddings: extract_expr(egraph, kind_children[3], expr_cache).unwrap(),
+                dtype: extract_dtype(egraph, kind_children[4]),
+            })),
+            input_enodes,
+        )
+    }
+}
+
+impl KernelOp for KernelEmbeddingBagSum {
+    fn compile(
+        &self,
+        stream: &Arc<CudaStream>,
+        compile_cache: &mut FxHashMap<String, (Arc<CudaModule>, CudaFunction)>,
+    ) -> (
+        CudaFunction,
+        Arc<CudaModule>,
+        String,
+        (Expression, Expression, Expression),
+        (Expression, Expression, Expression),
+        Expression,
+        FxHashMap<char, CudaSlice<u8>>,
+    ) {
+        assert!(
+            self.dtype == DType::F32,
+            "KernelEmbeddingBagSum only supports F32 weights today, got {:?}",
+            self.dtype
+        );
+        let vars = self
+            .n_bags
+            .dyn_vars()
+            .into_iter()
+            .chain(self.n_indices.dyn_vars())
+            .chain(self.hidden_dim.dyn_vars())
+            .chain(self.num_embeddings.dyn_vars())
+            .collect::<FxHashSet<_>>();
+        let (dyn_defines, _sorted_dims) = generate_dyn_dims_defines(&vars);
+        let dyn_dims_param = if vars.is_empty() {
+            ""
+        } else {
+            ", const int* dyn_dims"
+        };
+        let n_bags = self.n_bags.to_kernel();
+        let n_indices = self.n_indices.to_kernel();
+        let hidden_dim = self.hidden_dim.to_kernel();
+        let num_embeddings = self.num_embeddings.to_kernel();
+        let kernel = format!(
+            "
+{dyn_defines}
+extern \"C\" {{
+    __global__ void embedding_bag_sum(float *out, const float *weight, const int *indices, const int *offsets{dyn_dims_param}) {{
+        long long dim = (long long)blockIdx.x * blockDim.x + threadIdx.x;
+        long long bag = blockIdx.y;
+        long long hidden_dim = {hidden_dim};
+        long long n_bags = {n_bags};
+        long long n_indices = {n_indices};
+        long long num_embeddings = {num_embeddings};
+        if (bag >= n_bags || dim >= hidden_dim) return;
+
+        int start_raw = offsets[bag];
+        int end_raw = (bag + 1 < n_bags) ? offsets[bag + 1] : (int)n_indices;
+        int start = max(0, min(start_raw, (int)n_indices));
+        int end = max(start, min(end_raw, (int)n_indices));
+
+        float sum = 0.0f;
+        for (int pos = start; pos < end; ++pos) {{
+            int row = indices[pos];
+            row = max(0, min(row, (int)num_embeddings - 1));
+            sum += weight[(long long)row * hidden_dim + dim];
+        }}
+
+        out[bag * hidden_dim + dim] = sum;
+    }}
+}}"
+        );
+        let (module, func) = if let Some((module, func)) = compile_cache.get(&kernel) {
+            (module.clone(), func.clone())
+        } else {
+            let ptx = compile_module_image_for_current_device(stream.context(), &kernel).unwrap();
+            let module = stream.context().load_module(ptx).unwrap();
+            let func = module.load_function("embedding_bag_sum").unwrap();
+            compile_cache.insert(kernel.clone(), (module.clone(), func.clone()));
+            (module, func)
+        };
+        (
+            func,
+            module,
+            kernel,
+            (self.hidden_dim.ceil_div(256), self.n_bags, 1.into()),
+            (self.hidden_dim.min(256), 1.into(), 1.into()),
+            0.into(),
+            FxHashMap::default(),
+        )
+    }
+
+    fn output_size(&self) -> Expression {
+        self.n_bags * self.hidden_dim
+    }
+
+    fn all_dyn_vars(&self) -> FxHashSet<char> {
+        self.n_bags
+            .dyn_vars()
+            .into_iter()
+            .chain(self.n_indices.dyn_vars())
+            .chain(self.hidden_dim.dyn_vars())
+            .chain(self.num_embeddings.dyn_vars())
+            .collect()
+    }
+
+    fn output_bytes(&self) -> Expression {
+        self.output_size() * 4
+    }
+
+    fn bytes_loaded(&self) -> Expression {
+        // Approximate: weights + indices + offsets
+        self.n_indices * (self.hidden_dim * 4 + 4) + self.n_bags * 4
+    }
+
+    fn bytes_stored(&self) -> Expression {
+        self.output_bytes()
+    }
+
+    fn flops(&self) -> Expression {
+        self.n_indices * self.hidden_dim
+    }
+
+    fn output_dtype(&self) -> DType {
+        self.dtype
+    }
+
+    fn kernel_name(&self) -> &'static str {
+        "EmbeddingBagSum"
+    }
+}
+
+#[derive(Default, Debug, Clone)]
+pub struct KernelConcat2D {
+    rows: Expression,
+    lhs_cols: Expression,
+    rhs_cols: Expression,
+    dtype: DType,
+}
+
+impl EgglogOp for KernelConcat2D {
+    fn sort(&self) -> SortDef {
+        sort(
+            OP_KIND,
+            "KernelConcat2D",
+            &[
+                ("rows", EXPRESSION),
+                ("lhs_cols", EXPRESSION),
+                ("rhs_cols", EXPRESSION),
+                ("dtype", DTYPE),
+            ],
+        )
+    }
+
+    fn n_inputs(&self) -> usize {
+        2
+    }
+
+    fn rewrites(&self) -> Vec<Rule> {
+        vec![kernel_rewrite::<Concat2D, Self>()]
+    }
+
+    fn cleanup(&self) -> bool {
+        false
+    }
+
+    fn extract<'a>(
+        &'a self,
+        egraph: &'a SerializedEGraph,
+        kind_children: &[&'a ENodeId],
+        input_enodes: Vec<&'a ENodeId>,
+        _list_cache: &mut FxHashMap<&'a ENodeId, Vec<Expression>>,
+        expr_cache: &mut FxHashMap<&'a ENodeId, Expression>,
+    ) -> (LLIROp, Vec<&'a ENodeId>) {
+        (
+            LLIROp::new::<dyn KernelOp>(Box::new(Self {
+                rows: extract_expr(egraph, kind_children[0], expr_cache).unwrap(),
+                lhs_cols: extract_expr(egraph, kind_children[1], expr_cache).unwrap(),
+                rhs_cols: extract_expr(egraph, kind_children[2], expr_cache).unwrap(),
+                dtype: extract_dtype(egraph, kind_children[3]),
+            })),
+            input_enodes,
+        )
+    }
+}
+
+impl KernelOp for KernelConcat2D {
+    fn compile(
+        &self,
+        stream: &Arc<CudaStream>,
+        compile_cache: &mut FxHashMap<String, (Arc<CudaModule>, CudaFunction)>,
+    ) -> (
+        CudaFunction,
+        Arc<CudaModule>,
+        String,
+        (Expression, Expression, Expression),
+        (Expression, Expression, Expression),
+        Expression,
+        FxHashMap<char, CudaSlice<u8>>,
+    ) {
+        assert!(
+            self.dtype == DType::F32,
+            "KernelConcat2D only supports F32 today, got {:?}",
+            self.dtype
+        );
+        let vars = self
+            .rows
+            .dyn_vars()
+            .into_iter()
+            .chain(self.lhs_cols.dyn_vars())
+            .chain(self.rhs_cols.dyn_vars())
+            .collect::<FxHashSet<_>>();
+        let (dyn_defines, _sorted_dims) = generate_dyn_dims_defines(&vars);
+        let dyn_dims_param = if vars.is_empty() {
+            ""
+        } else {
+            ", const int* dyn_dims"
+        };
+        let rows = self.rows.to_kernel();
+        let lhs_cols = self.lhs_cols.to_kernel();
+        let rhs_cols = self.rhs_cols.to_kernel();
+        let total = (self.rows * (self.lhs_cols + self.rhs_cols)).to_kernel();
+        let kernel = format!(
+            "
+{dyn_defines}
+extern \"C\" {{
+    __global__ void concat_2d(float *out, const float *lhs, const float *rhs{dyn_dims_param}) {{
+        long long idx = (long long)blockIdx.x * blockDim.x + threadIdx.x;
+        long long total = {total};
+        if (idx >= total) return;
+
+        long long rows = {rows};
+        long long lhs_cols = {lhs_cols};
+        long long rhs_cols = {rhs_cols};
+        long long out_cols = lhs_cols + rhs_cols;
+        if (rows == 0 || out_cols == 0) return;
+
+        long long row = idx / out_cols;
+        long long col = idx - row * out_cols;
+        if (col < lhs_cols) {{
+            out[idx] = lhs[row * lhs_cols + col];
+        }} else {{
+            long long rhs_col = col - lhs_cols;
+            out[idx] = rhs[row * rhs_cols + rhs_col];
+        }}
+    }}
+}}"
+        );
+        let (module, func) = if let Some((module, func)) = compile_cache.get(&kernel) {
+            (module.clone(), func.clone())
+        } else {
+            let ptx = compile_module_image_for_current_device(stream.context(), &kernel).unwrap();
+            let module = stream.context().load_module(ptx).unwrap();
+            let func = module.load_function("concat_2d").unwrap();
+            compile_cache.insert(kernel.clone(), (module.clone(), func.clone()));
+            (module, func)
+        };
+        let output_size = self.output_size();
+        (
+            func,
+            module,
+            kernel,
+            (output_size.ceil_div(256), 1.into(), 1.into()),
+            (output_size.min(256), 1.into(), 1.into()),
+            0.into(),
+            FxHashMap::default(),
+        )
+    }
+
+    fn output_size(&self) -> Expression {
+        self.rows * (self.lhs_cols + self.rhs_cols)
+    }
+
+    fn all_dyn_vars(&self) -> FxHashSet<char> {
+        self.rows
+            .dyn_vars()
+            .into_iter()
+            .chain(self.lhs_cols.dyn_vars())
+            .chain(self.rhs_cols.dyn_vars())
+            .collect()
+    }
+
+    fn output_bytes(&self) -> Expression {
+        self.output_size() * 4
+    }
+
+    fn bytes_loaded(&self) -> Expression {
+        self.output_bytes()
+    }
+
+    fn bytes_stored(&self) -> Expression {
+        self.output_bytes()
+    }
+
+    fn flops(&self) -> Expression {
+        0.into()
+    }
+
+    fn output_dtype(&self) -> DType {
+        self.dtype
+    }
+
+    fn kernel_name(&self) -> &'static str {
+        "Concat2D"
+    }
+}

crates/luminal_cuda_lite/src/kernel/to_host.rs

@@ -4,6 +4,8 @@
 //! that can be executed like any other HostOp.
 
 use std::cell::RefCell;
+use std::cmp::Reverse;
+use std::collections::BTreeMap;
 use std::sync::Arc;
 
 use cudarc::driver::{
@@ -141,6 +143,8 @@ struct CudaGraphOpState {
     last_buffer_ptrs: FxHashMap<NodeIndex, u64>,
     /// Timing events for profiling
     timing_events: Vec<cudarc::driver::sys::CUevent>,
+    /// Last per-kernel GPU timings (microseconds) captured for diagnostics.
+    last_kernel_timings_us: Vec<(&'static str, f64)>,
 }
 
 impl CudaGraphOpState {
@@ -155,6 +159,7 @@ impl CudaGraphOpState {
             last_dyn_values: FxHashMap::default(),
             last_buffer_ptrs: FxHashMap::default(),
             timing_events: Vec::new(),
+            last_kernel_timings_us: Vec::new(),
         }
     }
 }
@@ -192,6 +197,41 @@ impl CudaGraphOp {
             state: RefCell::new(state),
         }
     }
+
+    pub fn debug_summary(&self) -> String {
+        let state = self.state.borrow();
+        let mut counts: BTreeMap<&'static str, usize> = BTreeMap::new();
+        for kernel in &state.kernels {
+            *counts.entry(kernel.kernel_name).or_default() += 1;
+        }
+        let mut counts: Vec<_> = counts.into_iter().collect();
+        counts.sort_by_key(|(name, count)| (Reverse(*count), *name));
+        let top = counts
+            .into_iter()
+            .take(4)
+            .map(|(name, count)| format!("{name}x{count}"))
+            .join(", ");
+        format!("CudaGraph[{} kernels: {top}]", state.kernels.len())
+    }
+
+    pub fn debug_timing_summary(&self) -> Option<String> {
+        let state = self.state.borrow();
+        if state.last_kernel_timings_us.is_empty() {
+            return None;
+        }
+        let mut totals: BTreeMap<&'static str, f64> = BTreeMap::new();
+        for (name, us) in &state.last_kernel_timings_us {
+            *totals.entry(*name).or_default() += *us;
+        }
+        let mut totals: Vec<_> = totals.into_iter().collect();
+        totals.sort_by(|a, b| b.1.total_cmp(&a.1).then_with(|| a.0.cmp(b.0)));
+        let top = totals
+            .into_iter()
+            .take(4)
+            .map(|(name, us)| format!("{name}={us:.0}us"))
+            .join(", ");
+        Some(top)
+    }
 }
 
 impl std::fmt::Debug for CudaGraphOp {
@@ -566,6 +606,23 @@ impl CudaGraphOp {
         // Launch the graph
         state.cuda_graph_exec.as_ref().unwrap().launch(stream)?;
 
+        if std::env::var_os("LUMINAL_PROFILE_CUDA_GRAPH").is_some()
+            && state.timing_events.len() >= state.kernels.len() + 1
+        {
+            stream.synchronize()?;
+            let ctx = stream.context().clone();
+            state.last_kernel_timings_us.clear();
+            for idx in 0..state.kernels.len() {
+                let start_event = state.timing_events[idx];
+                let end_event = state.timing_events[idx + 1];
+                let kernel_name = state.kernels[idx].kernel_name;
+                let us = crate::kernel::event_elapsed_ms(&ctx, start_event, end_event)
+                    .map(|ms| ms as f64 * 1_000.0)
+                    .unwrap_or(0.0);
+                state.last_kernel_timings_us.push((kernel_name, us));
+            }
+        }
+
         Ok(())
     }
 
@@ -584,8 +641,9 @@ impl CudaGraphOp {
         state.kernel_params.clear();
         state.kernel_params.reserve(num_kernels);
 
+        let profile_cuda_graph = std::env::var_os("LUMINAL_PROFILE_CUDA_GRAPH").is_some();
         let tracing_enabled = enabled!(Level::TRACE);
-        if tracing_enabled {
+        if tracing_enabled || profile_cuda_graph {
             let needed_events = num_kernels + 1;
             while state.timing_events.len() < needed_events {
                 state.timing_events.push(create_cuda_event(&ctx)?);
@@ -701,7 +759,7 @@ impl CudaGraphOp {
             }
 
             // Get timing event for this index (separate access from kernels)
-            let timing_event = if tracing_enabled {
+            let timing_event = if tracing_enabled || profile_cuda_graph {
                 Some(state.timing_events[idx])
             } else {
                 None
@@ -739,7 +797,9 @@ impl CudaGraphOp {
             prev_graph_node = Some(graph_node);
         }
 
-        if tracing_enabled && let Some(prev) = prev_graph_node {
+        if (tracing_enabled || profile_cuda_graph)
+            && let Some(prev) = prev_graph_node
+        {
             graph.add_event_record_node(&[prev], state.timing_events[num_kernels])?;
         }
 

crates/luminal_cuda_lite/src/runtime.rs

@@ -1,6 +1,9 @@
 use crate::{
-    host::{DeviceBuffer, HostOp},
-    kernel::{CudaGraphTiming, KernelOp, record_cuda_graph_timings},
+    host::{DeviceBuffer, HostOp, describe_host_op},
+    kernel::{
+        CudaGraphTiming, KernelOp, create_cuda_event, destroy_cuda_event, event_elapsed_ms,
+        record_cuda_graph_timings, record_event_on_stream,
+    },
 };
 use cudarc::driver::{CudaFunction, CudaModule, CudaSlice, CudaStream, DevicePtr, result};
 
@@ -60,6 +63,12 @@ pub struct KernelStats {
     pub tflops: f64,
 }
 
+#[derive(Debug, Clone)]
+pub struct HostOpStats {
+    pub name: String,
+    pub execution_time_us: f64,
+}
+
 impl Debug for ExecutableHostOp {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "HostOp: ({:?})", self.internal)
@@ -141,6 +150,7 @@ pub struct CudaRuntime {
     changed_hlir: FxHashSet<NodeIndex>,
     pub(crate) cuda_graph_timings: Vec<(CudaGraphTiming, Uuid)>,
     pub last_kernel_stats: Vec<KernelStats>,
+    pub last_host_op_stats: Vec<HostOpStats>,
     pub last_total_time_us: f64,
     kernel_cache: FxHashMap<String, (Arc<CudaModule>, CudaFunction)>,
     /// When true, execute() skips input buffer consumption (used during search/profile)
@@ -1203,6 +1213,7 @@ impl Runtime for CudaRuntime {
             changed_hlir: FxHashSet::default(),
             cuda_graph_timings: vec![],
             last_kernel_stats: vec![],
+            last_host_op_stats: vec![],
             last_total_time_us: 0.0,
             kernel_cache: FxHashMap::default(),
             profiling: false,
@@ -1454,6 +1465,8 @@ impl Runtime for CudaRuntime {
 
         let total_start = std::time::Instant::now();
         let bucket = &self.compiled_buckets[self.active_bucket];
+        let profile_host_ops = std::env::var_os("LUMINAL_PROFILE_HOST_OPS").is_some();
+        let mut host_timing_events = Vec::new();
 
         for exec_node in toposort(&bucket.exec_graph, None).unwrap() {
             let exec_op = &bucket.exec_graph[exec_node];
@@ -1507,6 +1520,16 @@ impl Runtime for CudaRuntime {
                 n_inputs = exec_op.inputs.len()
             )
             .entered();
+            let host_op_timing = if profile_host_ops {
+                let name = describe_host_op(exec_op.internal.as_ref().as_ref());
+                let ctx = exec_op.stream.context().clone();
+                let start_event = create_cuda_event(&ctx).unwrap();
+                let end_event = create_cuda_event(&ctx).unwrap();
+                record_event_on_stream(&ctx, start_event, &exec_op.stream).unwrap();
+                Some((name, ctx, start_event, end_event))
+            } else {
+                None
+            };
             exec_op
                 .internal
                 .execute(
@@ -1522,10 +1545,28 @@ impl Runtime for CudaRuntime {
                         exec_op.internal.stats_name().unwrap_or("unknown")
                     );
                 });
+            if let Some((name, ctx, start_event, end_event)) = host_op_timing {
+                record_event_on_stream(&ctx, end_event, &exec_op.stream).unwrap();
+                host_timing_events.push((name, ctx, start_event, end_event));
+            }
         }
         // Single sync at end - CUDA stream ordering guarantees sequential execution
         self.cuda_stream.synchronize().unwrap();
         self.last_total_time_us = total_start.elapsed().as_secs_f64() * 1_000_000.0;
+        self.last_host_op_stats.clear();
+        if profile_host_ops {
+            for (name, ctx, start_event, end_event) in host_timing_events {
+                let execution_time_us = event_elapsed_ms(&ctx, start_event, end_event)
+                    .map(|ms| ms as f64 * 1_000.0)
+                    .unwrap_or(0.0);
+                self.last_host_op_stats.push(HostOpStats {
+                    name,
+                    execution_time_us,
+                });
+                destroy_cuda_event(&ctx, start_event);
+                destroy_cuda_event(&ctx, end_event);
+            }
+        }
 
         // Populate last_kernel_stats from HostOps that report stats
         self.last_kernel_stats.clear();
@@ -1861,6 +1902,16 @@ impl CudaRuntime {
         let peak_bw = crate::cuda_bandwidth_gbps(self.cuda_stream.context());
         let peak_tf = crate::cuda_compute_f32_tflops(self.cuda_stream.context());
 
+        if !self.last_host_op_stats.is_empty() {
+            println!("\n=== Host Operation Statistics ===\n");
+            println!("{:<20} {:>12}", "HostOp", "Time (us)");
+            println!("{}", "-".repeat(34));
+            for s in &self.last_host_op_stats {
+                println!("{:<20} {:>12.2}", s.name, s.execution_time_us);
+            }
+            println!("{}", "-".repeat(34));
+        }
+
         // Print kernel stats
         if !self.last_kernel_stats.is_empty() {
             println!("\n=== Kernel Execution Statistics ===\n");

crates/luminal_cuda_lite/src/tests/qwen3_moe_rewrite.rs

@@ -71,9 +71,9 @@ fn build_qwen_moe_graph() -> QwenMoeGraph {
         .unsqueeze(2)
         .matmul(down_gathered.transpose(2, 3))
         .squeeze(2);
-    let mut weights_exp = top_k_values.unsqueeze(top_k_values.dims().len());
-    weights_exp.shape.expand(down_out.dims());
-    let output = (down_out * weights_exp).sum(n - 1).output();
+    let output = (down_out * top_k_values.unsqueeze(top_k_values.dims().len()))
+        .sum(n - 1)
+        .output();
 
     QwenMoeGraph {
         graph: cx,
@@ -130,9 +130,9 @@ fn build_gemma_moe_graph() -> GemmaMoeGraph {
         .unsqueeze(2)
         .matmul(down_gathered.transpose(2, 3))
         .squeeze(2);
-    let mut weights_exp = top_k_weights.unsqueeze(top_k_weights.dims().len());
-    weights_exp.shape.expand(down_out.dims());
-    let output = (down_out * weights_exp).sum(n - 1).output();
+    let output = (down_out * top_k_weights.unsqueeze(top_k_weights.dims().len()))
+        .sum(n - 1)
+        .output();
 
     GemmaMoeGraph {
         graph: cx,

crates/luminal_nn/src/moe.rs

@@ -61,8 +61,7 @@ impl MoE {
         let expert_out = expanded_act.matmul(gathered).squeeze(n); // [batch.., k, out]
 
         // 6. Weighted sum over experts: [batch.., k, out] * [batch.., k, 1] → sum(k) → [batch.., out]
-        let mut weights_exp = top_k_values.unsqueeze(top_k_values.dims().len()); // [batch.., k, 1]
-        weights_exp.shape.expand(expert_out.dims());
+        let weights_exp = top_k_values.unsqueeze(top_k_values.dims().len()); // [batch.., k, 1]
         (expert_out * weights_exp).sum(n - 1)
     }
 }
@@ -479,8 +478,7 @@ mod tests {
         let down_out = hidden_exp.matmul(down_gathered.transpose(2, 3)).squeeze(2); // [s, k, H]
 
         // 7. Weighted sum over k experts → [s, H]
-        let mut weights_exp = top_k_values.unsqueeze(top_k_values.dims().len()); // [s, k, 1]
-        weights_exp.shape.expand(down_out.dims());
+        let weights_exp = top_k_values.unsqueeze(top_k_values.dims().len()); // [s, k, 1]
         let _output = (down_out * weights_exp).sum(n - 1).output();
 
         // Dump the HLIR to egglog

crates/luminal_python/LessonsLearned.md

@@ -855,6 +855,8 @@ Two important details:
 
 Also: search-time dummy-1 inputs are not the same shape as runtime inputs. Anything you compute from a runtime tensor (cumsum offsets, routing indices, mask boundaries) needs to remain in-bounds for the dummy. Clamp index-producing chains as a matter of course, not just when the math says you "should" — `make_ones_bytes` is a hostile witness.
 
+---
+
 ## 2026-05-02 — Whisper port hit two missing-translator pitfalls
 
 1. **Symptom**: Compiling a PyTorch port of Whisper-tiny.en through `luminal_backend` failed twice in a row at the dispatch table: first with `Unsupported ATen op: torch.ops.aten.gelu.default`, then with `full: unsupported fill value type ... -Infinity`.

crates/luminal_python/rust/src/compiled_graph.rs

@@ -98,12 +98,7 @@ pub struct GraphTranslation {
     pub input_names: Vec<String>,
     pub output_names: Vec<String>,
     pub output_shape_exprs: Vec<Vec<Expression>>,
-    /// Output dtypes as PT2 dtype codes (e.g. 5 = int64, 7 = float32).
-    /// Stored as PT2 codes (rather than luminal `DType`) so we can preserve
-    /// distinctions luminal collapses internally — notably int64 vs int32,
-    /// both of which map to `DType::Int` in luminal but must be reported
-    /// back to PyTorch with their original precision.
-    pub output_dtypes: Vec<u32>,
+    pub output_dtypes: Vec<DType>,
     pub input_shape_exprs: Vec<Vec<Expression>>,
     pub dim_param_map: DimParamMap,
 }
@@ -129,9 +124,7 @@ pub struct CompiledGraph {
     pub output_names: Vec<String>,
     pub output_shapes: Vec<Vec<usize>>,
     pub output_shape_exprs: Vec<Vec<Expression>>,
-    /// Output dtypes as PT2 dtype codes (preserves int64 / int32 distinction
-    /// that luminal collapses to `DType::Int` internally).
-    pub output_dtypes: Vec<u32>,
+    pub output_dtypes: Vec<DType>,
     pub input_shape_exprs: Vec<Vec<Expression>>,
     pub dim_param_map: DimParamMap,
 }
@@ -255,6 +248,23 @@ impl CompiledGraph {
         self.runtime.device_type()
     }
 
+    /// Names of kernels compiled into the active runtime bucket, if available.
+    #[getter]
+    fn kernel_names(&self) -> Vec<String> {
+        self.runtime.kernel_names()
+    }
+
+    /// Names of host ops in the active runtime bucket, if available.
+    #[getter]
+    fn host_op_names(&self) -> Vec<String> {
+        self.runtime.host_op_names()
+    }
+
+    /// Print backend execution statistics for the last run, if supported.
+    fn print_execution_stats(&self) {
+        self.runtime.print_execution_stats();
+    }
+
     /// Whether the active backend supports device pointer operations (zero-copy GPU I/O).
     #[getter]
     fn supports_device_ptrs(&self) -> bool {
@@ -483,7 +493,10 @@ impl CompiledGraph {
     /// Get the PT2 dtype codes for all outputs (in order).
     #[getter]
     fn output_dtypes(&self) -> Vec<u32> {
-        self.output_dtypes.clone()
+        self.output_dtypes
+            .iter()
+            .map(|d| luminal_dtype_to_pt2_code(*d))
+            .collect()
     }
 
     /// Get output tensor data by name as f32 (copies to host).

crates/luminal_python/rust/src/pt2_compiled_model.rs

@@ -262,13 +262,10 @@ pub fn translate_pt2(
     let translated = translator::translate(&parsed)?;
     let mut graph = translated.graph;
 
-    // Set initial dynamic dim values from symbol ranges. PT2 emits
-    // `min_val: null` when the constraint is unbounded; fall back to 1 in
-    // that case (the smallest valid dim — used only as an initial value).
+    // Set initial dynamic dim values from symbol ranges
     for (sym_name, c) in &translated.sym_map.sym_to_char {
         if let Some(rc) = translated.sym_map.ranges.get(sym_name) {
-            let initial = rc.min_val.unwrap_or(1).max(0) as usize;
-            graph.set_dim(*c, initial);
+            graph.set_dim(*c, rc.min_val as usize);
         }
     }
 
@@ -284,14 +281,14 @@ pub fn translate_pt2(
         })
         .collect();
 
-    // Preserve original PT2 dtype codes for outputs (e.g. 5 = int64) so the
-    // Python wrapper can return tensors with the right torch.dtype, even when
-    // luminal collapses the type internally (e.g. int64 → DType::Int).
-    let output_dtypes: Vec<u32> = translated
+    let output_dtypes: Vec<DType> = translated
         .output_ids
         .iter()
         .map(|(name, _id)| {
-            parsed.tensor_meta(name).map(|meta| meta.dtype).unwrap_or(7) // default to f32
+            parsed
+                .tensor_meta(name)
+                .map(|meta| pt2_util::torch_dtype_int_to_luminal(meta.dtype))
+                .unwrap_or(DType::F32)
         })
         .collect();
 

crates/luminal_python/rust/src/pt2_schema.rs

@@ -15,16 +15,7 @@ pub struct ExportedProgram {
 
 #[derive(Debug, Clone, Deserialize)]
 pub struct RangeConstraint {
-    /// Lower bound on a symbolic dimension. PT2 emits `null` when the
-    /// constraint is unbounded (no min set), so this must accept None.
-    #[serde(default)]
-    pub min_val: Option<i64>,
-    /// Upper bound on a symbolic dimension. Also nullable in PT2. Currently
-    /// unused on the luminal side, but accepted to avoid deserialization
-    /// errors when PT2 emits it.
-    #[serde(default)]
-    #[allow(dead_code)]
-    pub max_val: Option<i64>,
+    pub min_val: i64,
 }
 
 #[derive(Debug, Deserialize)]

crates/luminal_python/rust/src/translator/binary.rs

@@ -1,4 +1,4 @@
-use anyhow::Result;
+use anyhow::{Result, bail};
 use luminal::prelude::*;
 
 use crate::pt2_schema::*;
@@ -8,21 +8,62 @@ use super::Translator;
 
 impl<'a> Translator<'a> {
     pub(crate) fn translate_binary_op(&mut self, node: &Node, op: BinaryOp) -> Result<GraphTensor> {
-        let a = self.get_input_tensor(node, 0)?;
-        let arg1 = &node.inputs[1].arg;
-        if let Some(name) = arg1.as_tensor_name() {
-            let b = self.get_tensor(name)?;
-            let (a, b) = ensure_same_dtype(a, b);
-            let (a, b) = broadcast_binary(a, b);
-            Ok(match op {
-                BinaryOp::Add => a + b,
-                BinaryOp::Mul => a * b,
-                BinaryOp::Sub => a - b,
-                BinaryOp::Div => a / b,
-            })
-        } else {
-            let val = self.get_float_arg(node, 1)? as f32;
-            Ok(self.apply_scalar_op(a, val, op))
+        let alpha = match op {
+            BinaryOp::Add | BinaryOp::Sub => self.get_float_arg(node, 2).unwrap_or(1.0) as f32,
+            BinaryOp::Mul | BinaryOp::Div => 1.0,
+        };
+
+        let lhs = node.inputs[0]
+            .arg
+            .as_tensor_name()
+            .map(|name| self.get_tensor(name))
+            .transpose()?;
+        let rhs = node.inputs[1]
+            .arg
+            .as_tensor_name()
+            .map(|name| self.get_tensor(name))
+            .transpose()?;
+
+        match (lhs, rhs) {
+            (Some(a), Some(mut b)) => {
+                if alpha != 1.0 {
+                    b = self.apply_scalar_op(b, alpha, BinaryOp::Mul);
+                }
+                let (a, b) = ensure_same_dtype(a, b);
+                let (a, b) = broadcast_binary(a, b);
+                Ok(match op {
+                    BinaryOp::Add => a + b,
+                    BinaryOp::Mul => a * b,
+                    BinaryOp::Sub => a - b,
+                    BinaryOp::Div => a / b,
+                })
+            }
+            (Some(a), None) => {
+                let mut val = self.get_float_arg(node, 1)? as f32;
+                if alpha != 1.0 {
+                    val *= alpha;
+                }
+                Ok(self.apply_scalar_op(a, val, op))
+            }
+            (None, Some(mut b)) => {
+                if alpha != 1.0 {
+                    b = self.apply_scalar_op(b, alpha, BinaryOp::Mul);
+                }
+                let lhs_val = self.get_float_arg(node, 0)? as f32;
+                let a = self
+                    .graph
+                    .constant_float(lhs_val)
+                    .cast(b.dtype)
+                    .expand_rhs(b.shape);
+                let (a, b) = broadcast_binary(a, b);
+                Ok(match op {
+                    BinaryOp::Add => a + b,
+                    BinaryOp::Mul => a * b,
+                    BinaryOp::Sub => a - b,
+                    BinaryOp::Div => a / b,
+                })
+            }
+            (None, None) => bail!("{} expects at least one tensor operand", node.target),
         }
     }
 

crates/luminal_python/rust/src/translator/conv.rs

@@ -173,7 +173,7 @@ impl<'a> Translator<'a> {
 
         if let Some(b) = bias {
             let out_dims = out.dims();
-            let mut b_expanded = b.expand_dim(0, out_dims[0]);
+            let mut b_expanded = b.expand_dim(0, 1);
             for i in 0..spatial {
                 b_expanded = b_expanded.expand_dim(2 + i, out_dims[2 + i]);
             }
@@ -389,11 +389,8 @@ fn depthwise_conv(
     // Expand to [N, C, group_out, out_spatial_product, kernel_product]
     let patches = patches.expand_dim(2, group_out);
 
-    // Explicitly expand weight across the batch axis so the elementwise Mul
-    // sees equal visible shapes. HLIR binary ops do not perform broadcasting.
-    let w_expanded = w_flat
-        .expand_dim(0, patches.dims()[0])
-        .expand_dim(3, patches.dims()[3]);
+    // Expand weight for broadcast: [1, C, group_out, out_spatial_product, kernel_product]
+    let w_expanded = w_flat.expand_dim(0, 1).expand_dim(3, patches.dims()[3]);
 
     // Element-wise multiply and sum over kernel dim
     let product = patches * w_expanded;

crates/luminal_python/rust/src/translator/dispatch.rs

@@ -6,7 +6,6 @@ use crate::pt2_util::*;
 
 use super::Translator;
 use super::attention::SdpaVariant;
-use super::reduction::ArgExtremum;
 
 impl<'a> Translator<'a> {
     pub(crate) fn translate_node(&mut self, node: &Node) -> Result<()> {
@@ -112,6 +111,7 @@ impl<'a> Translator<'a> {
                 result
             }
             "torch.ops.aten.expand.default" => self.translate_expand(node)?,
+            "torch.ops.aten.repeat.default" => self.translate_repeat(node)?,
             "torch.ops.aten.clone.default" => {
                 let a = self.get_input_tensor(node, 0)?;
                 if !a.shape.is_contiguous() { a + 0.0 } else { a }
@@ -134,8 +134,28 @@ impl<'a> Translator<'a> {
                 let beta = self.get_float_arg(node, 3).unwrap_or(1.0) as f32;
                 let alpha = self.get_float_arg(node, 4).unwrap_or(1.0) as f32;
                 let mm = mat1.matmul(mat2);
-                let (input, mm) = broadcast_binary(input, mm);
-                input * beta + mm * alpha
+                if alpha == 0.0 && beta == 0.0 {
+                    self.graph
+                        .constant_float(0.0)
+                        .cast(mm.dtype)
+                        .expand_rhs(mm.shape)
+                } else if beta == 0.0 {
+                    if alpha == 1.0 { mm } else { mm * alpha }
+                } else if alpha == 0.0 {
+                    let input = if beta == 1.0 { input } else { input * beta };
+                    let zero = self
+                        .graph
+                        .constant_float(0.0)
+                        .cast(input.dtype)
+                        .expand_rhs(mm.shape);
+                    let (input, _) = broadcast_binary(input, zero);
+                    input
+                } else {
+                    let input = if beta == 1.0 { input } else { input * beta };
+                    let mm = if alpha == 1.0 { mm } else { mm * alpha };
+                    let (input, mm) = broadcast_binary(input, mm);
+                    input + mm
+                }
             }
 
             // Convolution
@@ -151,6 +171,11 @@ impl<'a> Translator<'a> {
             "torch.ops.aten.select.int" => self.translate_select(node)?,
             "torch.ops.aten.cat.default" => self.translate_cat(node)?,
             "torch.ops.aten.index.Tensor" => self.translate_index_tensor(node)?,
+            "torch.ops.aten._embedding_bag.default"
+            | "torch.ops.aten._embedding_bag_forward_only.default" => {
+                self.translate_embedding_bag(node)?
+            }
+            "<built-in function getitem>" => self.translate_getitem(node)?,
 
             // Embedding
             "torch.ops.aten.embedding.default" => self.translate_embedding(node)?,
@@ -165,6 +190,9 @@ impl<'a> Translator<'a> {
 
             // LayerNorm
             "torch.ops.aten.native_layer_norm.default" => self.translate_layer_norm(node)?,
+            "torch.ops.aten._native_batch_norm_legit_no_training.default" => {
+                self.translate_native_batch_norm_no_training(node)?
+            }
 
             // Where
             "torch.ops.aten.where.self" => self.translate_where(node)?,
@@ -221,16 +249,6 @@ impl<'a> Translator<'a> {
             "torch.ops.aten.le.Scalar" => self.translate_scalar_comparison(node, |a, s| a.le(s))?,
 
             // Tensor comparisons
-            "torch.ops.aten.eq.Scalar" => {
-                let a = self.get_input_tensor(node, 0)?;
-                let val = self.get_float_arg(node, 1)? as f32;
-                let scalar = self
-                    .graph
-                    .constant_float(val)
-                    .cast(a.dtype)
-                    .expand_rhs(a.shape);
-                a.eq(scalar)
-            }
             "torch.ops.aten.ne.Scalar" => {
                 let a = self.get_input_tensor(node, 0)?;
                 let val = self.get_float_arg(node, 1)? as f32;
@@ -248,13 +266,6 @@ impl<'a> Translator<'a> {
                 let (a, b) = broadcast_binary(a, b);
                 a.eq(b)
             }
-            "torch.ops.aten.ne.Tensor" => {
-                let a = self.get_input_tensor(node, 0)?;
-                let b = self.get_input_tensor(node, 1)?;
-                let (a, b) = ensure_same_dtype(a, b);
-                let (a, b) = broadcast_binary(a, b);
-                a.ne(b)
-            }
             "torch.ops.aten.le.Tensor" => {
                 let a = self.get_input_tensor(node, 0)?;
                 let b = self.get_input_tensor(node, 1)?;
@@ -293,27 +304,18 @@ impl<'a> Translator<'a> {
 
             // Clamp
             "torch.ops.aten.clamp.default" => self.translate_clamp(node)?,
-            "torch.ops.aten.clamp.Tensor" => self.translate_clamp_tensor(node)?,
 
             // Cumsum
             "torch.ops.aten.cumsum.default" => {
                 let a = self.get_input_tensor(node, 0)?;
+                let dim = self.get_int_arg(node, 1)?;
+                let dim = normalize_dim(dim, a.shape.len());
                 let a = if a.dtype == DType::Bool {
                     a.cast(DType::Int)
                 } else {
                     a
                 };
-                // Rank-0 (scalar) input: cumsum of a single element is the element
-                // itself. PyTorch eager treats `dim=0` on a 0-d as an identity op,
-                // and the underlying `cumop` indexes `shape.dims[axis]` which would
-                // panic with empty dims.
-                if a.shape.is_empty() {
-                    a
-                } else {
-                    let dim = self.get_int_arg(node, 1)?;
-                    let dim = normalize_dim(dim, a.shape.len());
-                    a.cumsum(dim)
-                }
+                a.cumsum(dim)
             }
 
             // Floor / Ceil / Erf (approximations)
@@ -409,17 +411,6 @@ impl<'a> Translator<'a> {
             "torch.ops.aten.max.default" => self.translate_reduction(node, ReductionOp::Max)?,
             "torch.ops.aten.min.default" => self.translate_reduction(node, ReductionOp::Min)?,
             "torch.ops.aten.amin.default" => self.translate_reduction(node, ReductionOp::Min)?,
-            "torch.ops.aten.prod.default" => self.translate_reduction(node, ReductionOp::Prod)?,
-
-            // Argmax / argmin — built on top of `stable_argsort` (LUM-496).
-            // PyTorch's argmax/argmin returns int64; the dtype is preserved
-            // through the LUM-486 boundary widening.
-            "torch.ops.aten.argmax.default" => {
-                self.translate_argextremum(node, ArgExtremum::Max)?
-            }
-            "torch.ops.aten.argmin.default" => {
-                self.translate_argextremum(node, ArgExtremum::Min)?
-            }
 
             // Gather (axis-aware)
             "torch.ops.aten.gather.default" => self.translate_gather(node)?,
@@ -483,28 +474,6 @@ impl<'a> Translator<'a> {
                 let (a, b) = broadcast_binary(a, b);
                 a % b
             }
-            // Remainder (Python-style modulo). For float tensors aten.remainder
-            // returns the same value as `%` would in luminal (Mod follows the
-            // language's % semantics on f32). The Tensor variant accepts a
-            // tensor RHS that may be rank-0; broadcast both operands so a
-            // scalar RHS is expanded to match the LHS shape before mod.
-            "torch.ops.aten.remainder.Tensor" => {
-                let a = self.get_input_tensor(node, 0)?;
-                let b = self.get_input_tensor(node, 1)?;
-                let (a, b) = ensure_same_dtype(a, b);
-                let (a, b) = broadcast_binary(a, b);
-                a % b
-            }
-            "torch.ops.aten.remainder.Scalar" => {
-                let a = self.get_input_tensor(node, 0)?;
-                let val = self.get_float_arg(node, 1)? as f32;
-                let scalar = self
-                    .graph
-                    .constant_float(val)
-                    .cast(a.dtype)
-                    .expand_rhs(a.shape);
-                a % scalar
-            }
             // Prod reduction
             "torch.ops.aten.prod.dim_int" => self.translate_reduction(node, ReductionOp::Prod)?,
 

crates/luminal_python/rust/src/translator/movement.rs

@@ -12,6 +12,64 @@ const SCATTER_INDEX_ARG: usize = 2;
 const SCATTER_VALUE_ARG: usize = 3;
 
 impl<'a> Translator<'a> {
+    fn try_concat_2d_fast(
+        &mut self,
+        lhs: GraphTensor,
+        rhs: GraphTensor,
+        axis: usize,
+    ) -> Option<GraphTensor> {
+        if axis != 1
+            || lhs.dtype != DType::F32
+            || rhs.dtype != DType::F32
+            || lhs.shape.len() != 2
+            || rhs.shape.len() != 2
+            || !lhs.shape.is_contiguous()
+            || !rhs.shape.is_contiguous()
+            || lhs.shape.dims[0] != rhs.shape.dims[0]
+        {
+            return None;
+        }
+
+        let rows = lhs.shape.dims[0];
+        let lhs_cols = lhs.shape.dims[1];
+        let rhs_cols = rhs.shape.dims[1];
+        let id = self.graph.add_op(
+            luminal::hlir::Concat2D {
+                rows,
+                lhs_cols,
+                rhs_cols,
+            },
+            &[lhs.id, rhs.id],
+        );
+
+        Some(GraphTensor::from_id(
+            id,
+            ShapeTracker::new(vec![rows, lhs_cols + rhs_cols]),
+            lhs.graph_ref,
+            lhs.dtype,
+        ))
+    }
+
+    pub(crate) fn translate_select(&mut self, node: &Node) -> Result<GraphTensor> {
+        let a = self.get_input_tensor(node, 0)?;
+        let dim = normalize_dim(self.get_int_arg(node, 1).unwrap_or(0), a.shape.len());
+        let index = self
+            .get_int_arg(node, 2)
+            .context("select.int: missing index")?;
+
+        let dim_size = a.shape.dims[dim]
+            .to_usize()
+            .context("select.int: symbolic dims are not supported for negative indices")?;
+        let normalized_index = if index < 0 {
+            (dim_size as i64 + index) as usize
+        } else {
+            index as usize
+        };
+
+        Ok(a.slice_along(normalized_index..normalized_index + 1, dim)
+            .squeeze(dim))
+    }
+
     pub(crate) fn translate_reshape(&mut self, node: &Node) -> Result<GraphTensor> {
         let a = self.get_input_tensor(node, 0)?;
 
@@ -80,6 +138,43 @@ impl<'a> Translator<'a> {
         Ok(a)
     }
 
+    pub(crate) fn translate_repeat(&mut self, node: &Node) -> Result<GraphTensor> {
+        let mut a = self.get_input_tensor(node, 0)?;
+        let repeats: Vec<Expression> = if let Ok(sizes) = self.get_ints_arg(node, 1) {
+            sizes
+                .into_iter()
+                .map(|size| {
+                    anyhow::ensure!(size >= 0, "repeat: negative repeats are not supported");
+                    Ok(Expression::from(size as usize))
+                })
+                .collect::<Result<_>>()?
+        } else {
+            self.get_exprs_arg(node, 1)?
+        };
+
+        anyhow::ensure!(
+            repeats.len() >= a.shape.len(),
+            "repeat: repeats rank {} is smaller than input rank {}",
+            repeats.len(),
+            a.shape.len()
+        );
+
+        while a.shape.len() < repeats.len() {
+            a = a.unsqueeze(0);
+        }
+
+        Ok(a.repeat(repeats))
+    }
+
+    pub(crate) fn translate_getitem(&mut self, node: &Node) -> Result<GraphTensor> {
+        let index = self.get_int_arg(node, 1)?;
+        anyhow::ensure!(
+            index == 0,
+            "getitem: only tuple[0] access is supported today, got index={index}"
+        );
+        self.get_input_tensor(node, 0)
+    }
+
     pub(crate) fn translate_slice(&mut self, node: &Node) -> Result<GraphTensor> {
         let a = self.get_input_tensor(node, 0)?;
         let dim = self.get_int_arg(node, 1).unwrap_or(0);
@@ -120,47 +215,6 @@ impl<'a> Translator<'a> {
         Ok(a.slice_along(start..end, dim))
     }
 
-    /// `aten.select.int(self, dim, index)` — select element `index` along
-    /// `dim`, dropping that dim. Output rank = input rank − 1, so a 1-D input
-    /// produces a rank-0 scalar. Both `dim` and `index` may be negative and
-    /// are normalized against the input shape.
-    ///
-    /// Lowered as `slice_along(index..index+1, dim).squeeze(dim)`. We use the
-    /// slice + squeeze decomposition (rather than `gather`) because the
-    /// composition is a pure shape manipulation with a single iota, which the
-    /// luminal compiler can fold into surrounding ops.
-    pub(crate) fn translate_select(&mut self, node: &Node) -> Result<GraphTensor> {
-        let a = self.get_input_tensor(node, 0)?;
-        let dim = self.get_int_arg(node, 1)?;
-        let dim = normalize_dim(dim, a.shape.len());
-        let index_raw = self.get_int_arg(node, 2)?;
-
-        // Normalize a possibly-negative index. PyTorch accepts indices in
-        // [-size, size); negative wraps from the end.
-        let index = if index_raw < 0 {
-            let axis_size = a.shape.dims[dim].to_usize().ok_or_else(|| {
-                anyhow::anyhow!(
-                    "select.int: dim {} must be concrete to normalize a negative index",
-                    dim
-                )
-            })?;
-            let normalized = axis_size as i64 + index_raw;
-            if normalized < 0 {
-                bail!(
-                    "select.int: index {} out of range for dim {} of size {}",
-                    index_raw,
-                    dim,
-                    axis_size
-                );
-            }
-            normalized as usize
-        } else {
-            index_raw as usize
-        };
-
-        Ok(a.slice_along(index..index + 1, dim).squeeze(dim))
-    }
-
     pub(crate) fn translate_cat(&mut self, node: &Node) -> Result<GraphTensor> {
         let tensors: Vec<GraphTensor> = if let Some(names) = node.inputs[0].arg.as_tensors() {
             names
@@ -202,7 +256,11 @@ impl<'a> Translator<'a> {
         let dim = normalize_dim(dim, tensors[0].shape.len());
         let mut result = tensors[0];
         for t in &tensors[1..] {
-            result = result.concat_along(*t, dim);
+            if let Some(fast) = self.try_concat_2d_fast(result, *t, dim) {
+                result = fast;
+            } else {
+                result = result.concat_along(*t, dim);
+            }
         }
         Ok(result)
     }
@@ -259,6 +317,79 @@ impl<'a> Translator<'a> {
                     bail!("index.Tensor: no index tensors in optional_tensors list");
                 }
                 index_names = found_tensors;
+
+                // Multiple explicit index tensors after leading `None`s mean
+                // "keep the prefix dims, then advanced-index the contiguous
+                // tail dims". DLRM's `Z[:, li, lj]` is exactly this pattern.
+                if first_non_none_dim > 0
+                    && index_names.len() > 1
+                    && first_non_none_dim + index_names.len() == source.shape.len()
+                {
+                    let src_dims = source.shape.dims;
+                    let indexed_dims = &src_dims[first_non_none_dim..];
+                    let n_indexed = index_names.len();
+
+                    let mut strides: Vec<Expression> = vec![Expression::from(1usize); n_indexed];
+                    for i in (0..n_indexed - 1).rev() {
+                        strides[i] = strides[i + 1] * indexed_dims[i + 1];
+                    }
+
+                    let mut flat_idx: Option<GraphTensor> = None;
+                    for (dim_idx, idx_name) in index_names.iter().enumerate() {
+                        let idx_tensor = self.get_tensor(&idx_name.name)?;
+                        let axis_size = indexed_dims[dim_idx];
+                        let idx_int = idx_tensor.cast(DType::Int);
+                        let zero = self.graph.constant(0).expand_rhs(idx_int.shape);
+                        let is_negative = idx_int.lt(zero).cast(DType::Int);
+                        let idx_int = idx_int + is_negative * axis_size;
+
+                        let stride = strides[dim_idx];
+                        let weighted = if stride.to_usize() == Some(1) {
+                            idx_int
+                        } else {
+                            idx_int * stride
+                        };
+
+                        flat_idx = Some(match flat_idx {
+                            Some(acc) => {
+                                let (acc_b, w_b) = broadcast_binary(acc, weighted);
+                                acc_b + w_b
+                            }
+                            None => weighted,
+                        });
+                    }
+
+                    let flat_idx = flat_idx.context("index.Tensor: no indices")?;
+                    let idx_shape = flat_idx.shape.dims.to_vec();
+                    let mut idx_numel = Expression::from(1usize);
+                    for dim in &idx_shape {
+                        idx_numel *= *dim;
+                    }
+                    let flat_idx = reshape_tensor(flat_idx, vec![idx_numel]);
+
+                    let prefix_dims = src_dims[..first_non_none_dim].to_vec();
+                    let mut indexed_size = Expression::from(1usize);
+                    for dim in indexed_dims {
+                        indexed_size *= *dim;
+                    }
+                    let mut flat_source_shape = prefix_dims.clone();
+                    flat_source_shape.push(indexed_size);
+                    let flat_source = reshape_tensor(source, flat_source_shape);
+
+                    let mut expanded_idx = flat_idx;
+                    for _ in 0..prefix_dims.len() {
+                        expanded_idx = expanded_idx.expand_dim(0, Expression::from(1usize));
+                    }
+                    let mut target = prefix_dims.clone();
+                    target.push(idx_numel);
+                    expanded_idx.shape.expand(target);
+
+                    let gathered = flat_source.gather_elements(expanded_idx, prefix_dims.len());
+                    let mut result_shape = prefix_dims;
+                    result_shape.extend_from_slice(&idx_shape);
+                    return Ok(reshape_tensor(gathered, result_shape));
+                }
+
                 // Simple case: single non-None index on a specific dim → gather_elements
                 if first_non_none_dim > 0 && index_names.len() == 1 {
                     let idx = self.get_tensor(&index_names[0].name)?.cast(DType::Int);
@@ -374,17 +505,6 @@ impl<'a> Translator<'a> {
         let dim = normalize_dim(dim, a.shape.len());
         let indices = self.get_input_tensor(node, 2)?;
 
-        // PyTorch eager allows torch.gather(rank-1, 0, rank-0) and returns
-        // a rank-0 scalar — the only rank-mismatch case eager permits. Our
-        // gather_elements requires the index rank to match the source rank,
-        // so unsqueeze the rank-0 index to (1,), gather, then squeeze back.
-        let promoted_rank0 = indices.shape.is_empty() && a.shape.len() == 1;
-        let indices = if promoted_rank0 {
-            indices.unsqueeze(0)
-        } else {
-            indices
-        };
-
         // Normalize negative indices: -1 → last, -2 → second-to-last, etc.
         // Stay in Int the whole way — multiplying an Int tensor by an
         // Expression broadcasts the axis size and avoids three Cast nodes
@@ -396,12 +516,7 @@ impl<'a> Translator<'a> {
         let is_negative = indices_int.lt(zero).cast(DType::Int);
         let normalized = indices_int + is_negative * axis_dim;
 
-        let result = a.gather_elements(normalized, dim);
-        Ok(if promoted_rank0 {
-            result.squeeze(0)
-        } else {
-            result
-        })
+        Ok(a.gather_elements(normalized, dim))
     }
 
     pub(crate) fn translate_scatter_src(&mut self, node: &Node) -> Result<GraphTensor> {

crates/luminal_python/rust/src/translator/reduction.rs

@@ -6,20 +6,6 @@ use crate::pt2_util::*;
 
 use super::Translator;
 
-/// Whether `argmax` / `argmin` should pick the largest (descending sort) or
-/// smallest (ascending sort) element when scanning the input.
-#[derive(Clone, Copy)]
-pub(crate) enum ArgExtremum {
-    Max,
-    Min,
-}
-
-impl ArgExtremum {
-    fn descending(self) -> bool {
-        matches!(self, ArgExtremum::Max)
-    }
-}
-
 /// Compute total element count, returning an error if any dimension is symbolic.
 fn concrete_numel(a: &GraphTensor) -> Result<usize> {
     a.dims().iter().try_fold(1usize, |acc, d| {
@@ -51,26 +37,32 @@ impl<'a> Translator<'a> {
                 (axes, keepdim)
             }
             _ => {
-                // Full reduce: reduce over every axis, leaving a rank-0 (scalar) tensor.
-                // PyTorch eager returns shape () for `x.sum()` etc., and downstream ops
-                // (e.g. unsqueeze(0).expand(N)) rely on this rank.
-                let ndim = a.shape.len();
-                if ndim == 0 {
-                    // Already rank-0 — reducing over no axes is a no-op for sum/max/min/prod,
-                    // and mean of a scalar is just the scalar.
-                    return Ok(a);
-                }
+                // Full reduce: flatten to [1, N] and reduce axis 1. The shape
+                // override below assumes contiguous, no-broadcast storage —
+                // otherwise the `[1, N]` view treats stride-0 broadcast dims
+                // as if they held N distinct values and reads past the backing
+                // buffer. Materialize first when that's not the case (matches
+                // the guard `translate_reshape` already applies).
                 let total = concrete_numel(&a)?;
-                let axes: Vec<usize> = (0..ndim).collect();
+                let has_broadcast = a
+                    .shape
+                    .dims
+                    .iter()
+                    .zip(a.shape.strides.iter())
+                    .any(|(d, s)| s.to_usize() == Some(0) && d.to_usize() != Some(1));
+                let a = if has_broadcast || !a.shape.is_contiguous() {
+                    a + 0.0
+                } else {
+                    a
+                };
+                let mut flat = a;
+                flat.shape = ShapeTracker::new(vec![1, total]);
                 let result = match op {
-                    ReductionOp::Sum => a.sum(axes),
-                    // Note: the luminal `mean` helper divides by the product of the
-                    // axis dims, but we already require concrete dims here so we
-                    // divide by the cached `total` to avoid recomputing.
-                    ReductionOp::Mean => a.sum(axes) / total as f32,
-                    ReductionOp::Max => a.max(axes),
-                    ReductionOp::Min => a.min(axes),
-                    ReductionOp::Prod => a.prod(axes),
+                    ReductionOp::Sum => flat.sum(vec![1]),
+                    ReductionOp::Mean => flat.sum(vec![1]) / total as f32,
+                    ReductionOp::Max => flat.max(vec![1]),
+                    ReductionOp::Min => flat.min(vec![1]),
+                    ReductionOp::Prod => flat.prod(vec![1]),
                 };
                 return Ok(result);
             }
@@ -94,100 +86,4 @@ impl<'a> Translator<'a> {
 
         Ok(result)
     }
-
-    /// Lower `aten.argmax.default` / `aten.argmin.default` by reusing the
-    /// existing `stable_argsort` op and selecting the first index along the
-    /// sort axis.
-    ///
-    /// PyTorch signature: `argmax(self, dim=None, keepdim=False)` (likewise
-    /// for argmin). FX export emits the inputs positionally:
-    ///   - input 0: tensor
-    ///   - input 1: dim (Int) or None (Other) — when `dim=None`
-    ///   - input 2: keepdim (Bool, optional)
-    ///
-    /// When `dim=None`, PyTorch flattens the tensor; we mirror that by
-    /// reshaping to a 1-D `[numel]` view (which requires concrete dims).
-    /// The result of argsort along the sort axis is sliced at index 0,
-    /// then squeezed away — i.e. `select(dim, 0)` — to give the index of
-    /// the extremum. With `keepdim=True` we re-insert a size-1 dim at
-    /// `dim`.
-    ///
-    /// The slice + squeeze chain produces a non-contiguous `DType::Int`
-    /// view; we materialize it with `* 1` so the resulting node has
-    /// contiguous strides matching its visible shape (mirroring the
-    /// `topk` lowering in `translate_topk`). Without this, the output
-    /// buffer would be sized for the un-sliced argsort tensor while the
-    /// shape tracker reports a smaller rank.
-    ///
-    /// The output dtype is `DType::Int` (luminal's 32-bit int); PT2
-    /// metadata records int64 and the Python wrapper widens at the
-    /// boundary, so the PyTorch contract is preserved end-to-end
-    /// (LUM-486).
-    pub(crate) fn translate_argextremum(
-        &mut self,
-        node: &Node,
-        which: ArgExtremum,
-    ) -> Result<GraphTensor> {
-        let a = self.get_input_tensor(node, 0)?;
-
-        // dim is positional input 1. PyTorch encodes `dim=None` as a non-Int
-        // argument (typically `Argument::Other(Null)`), so a missing or
-        // non-int slot means "reduce over the flattened tensor".
-        let dim_opt: Option<i64> = if node.inputs.len() > 1 {
-            self.get_int_arg(node, 1).ok()
-        } else {
-            None
-        };
-        let keepdim = if node.inputs.len() > 2 {
-            self.get_bool_arg(node, 2).unwrap_or(false)
-        } else {
-            false
-        };
-
-        if a.shape.is_empty() {
-            match dim_opt {
-                None | Some(0) | Some(-1) => {
-                    // PyTorch returns scalar index 0 for rank-0 argmax/argmin.
-                    // `keepdim=True` does not add a dimension when the input is 0-d.
-                    return Ok(self.graph.constant(0i64).cast(DType::Int));
-                }
-                Some(dim) => {
-                    return Err(anyhow::anyhow!(
-                        "Dimension out of range (expected to be in range of [-1, 0], but got {dim})"
-                    ));
-                }
-            }
-        }
-
-        let descending = which.descending();
-
-        let (sort_axis, base) = match dim_opt {
-            None => {
-                // Full-reduce: flatten to 1-D, argsort along axis 0.
-                let total = concrete_numel(&a)?;
-                let flat = reshape_tensor(a, vec![Expression::from(total)]);
-                (0usize, flat)
-            }
-            Some(dim_raw) => {
-                let dim = normalize_dim(dim_raw, a.shape.len());
-                (dim, a)
-            }
-        };
-
-        // Pick index 0 along the sort axis. The slice-then-squeeze chain
-        // produces a non-contiguous view whose physical buffer is still
-        // sized for the un-sliced argsort tensor; the optional `keepdim`
-        // unsqueeze adds a stride-0 axis which is also non-contiguous.
-        // Materialize at the end with `* 1` so the resulting node has
-        // contiguous strides matching its visible shape (matches the
-        // pattern used by `translate_topk` for sliced index outputs).
-        let sorted = base.stable_argsort(sort_axis, descending);
-        let picked = sorted.slice_along(0..1, sort_axis).squeeze(sort_axis);
-        let result = if keepdim {
-            picked.unsqueeze(sort_axis)
-        } else {
-            picked
-        };
-        Ok(result * 1)
-    }
 }

crates/luminal_python/rust/src/translator/tensor.rs

@@ -28,6 +28,45 @@ const TRIANGULAR_INPUT_ARG: usize = 0;
 const TRIANGULAR_DIAGONAL_ARG: usize = 1;
 
 impl<'a> Translator<'a> {
+    fn translate_embedding_bag_generic(
+        &mut self,
+        weight: GraphTensor,
+        indices: GraphTensor,
+        offsets: GraphTensor,
+    ) -> Result<GraphTensor> {
+        let hidden_dim = weight.shape.dims[1];
+        let n_indices = indices.shape.dims[0];
+        let n_bags = offsets.shape.dims[0];
+
+        // Gather per-index embeddings: [E] -> [E, D].
+        let ids_expanded = (indices * hidden_dim).expand_dim(1, hidden_dim);
+        let arange = self.graph.arange(hidden_dim).expand_dim(0, n_indices);
+        let gathered = weight.gather(ids_expanded + arange);
+
+        // Bag assignment per position:
+        //   bag_id[pos] = count(offsets <= pos) - 1
+        // This supports empty bags too, because repeated offsets simply skip a
+        // bag id when no positions land in that interval.
+        let positions = self.graph.arange(n_indices).expand_dim(0, n_bags);
+        let starts = offsets.expand_dim(1, n_indices);
+        let bag_ids = positions.ge(starts).cast(DType::Int).sum(0)
+            - self
+                .graph
+                .constant_float(1.0)
+                .cast(DType::Int)
+                .expand_rhs(vec![n_indices]);
+
+        let bag_axis = self.graph.arange(n_bags).expand_dim(1, n_indices);
+        let bag_ids = bag_ids.expand_dim(0, n_bags);
+        let mask = bag_ids
+            .eq(bag_axis)
+            .expand_dim(2, hidden_dim)
+            .cast(gathered.dtype);
+        let gathered = gathered.expand_dim(0, n_bags);
+
+        Ok((gathered * mask).sum(1))
+    }
+
     pub(crate) fn translate_arange(&mut self, node: &Node) -> Result<GraphTensor> {
         let positional_args: Vec<Expression> = node
             .inputs
@@ -180,6 +219,45 @@ impl<'a> Translator<'a> {
         Ok(value.expand_rhs(reference.shape))
     }
 
+    pub(crate) fn translate_embedding_bag(&mut self, node: &Node) -> Result<GraphTensor> {
+        let weight = self.get_input_tensor(node, 0)?;
+        let indices = self.get_input_tensor(node, 1)?.cast(DType::Int);
+        let offsets = self.get_input_tensor(node, 2)?.cast(DType::Int);
+
+        let mode = self.get_int_arg(node, 4).unwrap_or(0);
+        anyhow::ensure!(
+            mode == 0,
+            "_embedding_bag: only mode=0 (sum) is supported, got mode={mode}"
+        );
+
+        anyhow::ensure!(
+            indices.shape.len() == 1 && offsets.shape.len() == 1,
+            "_embedding_bag: expected 1D indices/offsets, got indices={}D offsets={}D",
+            indices.shape.len(),
+            offsets.shape.len()
+        );
+
+        if weight.dtype == DType::F32 {
+            let id = self.graph.add_op(
+                luminal::hlir::EmbeddingBagSum {
+                    n_bags: offsets.shape.dims[0],
+                    n_indices: indices.shape.dims[0],
+                    hidden_dim: weight.shape.dims[1],
+                    num_embeddings: weight.shape.dims[0],
+                },
+                &[weight.id, indices.id, offsets.id],
+            );
+            return Ok(GraphTensor::from_id(
+                id,
+                ShapeTracker::new(vec![offsets.shape.dims[0], weight.shape.dims[1]]),
+                weight.graph_ref,
+                DType::F32,
+            ));
+        }
+
+        self.translate_embedding_bag_generic(weight, indices, offsets)
+    }
+
     fn output_meta_dtype(&self, node: &Node) -> Result<DType> {
         let output_name = node
             .outputs

crates/luminal_python/rust/src/translator/unary.rs

@@ -21,6 +21,30 @@ const DIV_MODE_INPUT_ARG: usize = 0;
 const DIV_MODE_OTHER_ARG: usize = 1;
 
 impl<'a> Translator<'a> {
+    fn expand_channel_parameter(
+        &self,
+        input: GraphTensor,
+        parameter: GraphTensor,
+    ) -> Result<GraphTensor> {
+        anyhow::ensure!(
+            input.shape.len() >= 2,
+            "batch_norm: expected rank >= 2 input, got rank {}",
+            input.shape.len()
+        );
+        anyhow::ensure!(
+            parameter.shape.len() == 1,
+            "batch_norm: expected 1D channel parameter, got rank {}",
+            parameter.shape.len()
+        );
+
+        let mut expanded = parameter.unsqueeze(0);
+        for axis in 2..input.shape.len() {
+            expanded = expanded.unsqueeze(axis);
+        }
+        expanded.shape.expand(input.dims().to_vec());
+        Ok(expanded)
+    }
+
     pub(crate) fn translate_argsort(&mut self, node: &Node) -> Result<GraphTensor> {
         let a = self.get_input_tensor(node, ARGSORT_INPUT_ARG)?;
         let dim = if node.inputs.len() > ARGSORT_DIM_ARG {
@@ -101,6 +125,30 @@ impl<'a> Translator<'a> {
         Ok(result)
     }
 
+    pub(crate) fn translate_native_batch_norm_no_training(
+        &mut self,
+        node: &Node,
+    ) -> Result<GraphTensor> {
+        let input = self.get_input_tensor(node, 0)?;
+        let running_mean = self.expand_channel_parameter(input, self.get_input_tensor(node, 3)?)?;
+        let running_var = self.expand_channel_parameter(input, self.get_input_tensor(node, 4)?)?;
+        let eps = self.get_float_arg(node, 6).unwrap_or(1e-5) as f32;
+
+        let mut result = (input - running_mean) / (running_var + eps).sqrt();
+
+        if let Some(weight_name) = node.inputs.get(1).and_then(|i| i.arg.as_tensor_name()) {
+            let weight = self.expand_channel_parameter(input, self.get_tensor(weight_name)?)?;
+            result = result * weight;
+        }
+
+        if let Some(bias_name) = node.inputs.get(2).and_then(|i| i.arg.as_tensor_name()) {
+            let bias = self.expand_channel_parameter(input, self.get_tensor(bias_name)?)?;
+            result = result + bias;
+        }
+
+        Ok(result)
+    }
+
     pub(crate) fn translate_sign(&mut self, node: &Node) -> Result<GraphTensor> {
         let a = self.get_input_tensor(node, 0)?;
         let zero = self
@@ -213,18 +261,12 @@ impl<'a> Translator<'a> {
         let (a, b) = crate::pt2_util::ensure_same_dtype(a, b);
         let (a, b) = broadcast_binary(a, b);
 
-        // Check rounding_mode kwarg. PT2 serializes string args as
-        // {"as_string": "<value>"}, so we have to drill into the JSON.
+        // Check rounding_mode kwarg
         let rounding_mode = node.inputs.iter().find_map(|input| {
             if input.name == "rounding_mode"
                 && let Argument::Other(val) = &input.arg
             {
-                if let Some(s) = val.as_str() {
-                    return Some(s.to_string());
-                }
-                if let Some(s) = val.get("as_string").and_then(|v| v.as_str()) {
-                    return Some(s.to_string());
-                }
+                return val.as_str().map(|s| s.to_string());
             }
             None
         });
@@ -275,52 +317,4 @@ impl<'a> Translator<'a> {
         }
         Ok(result)
     }
-
-    /// `aten.clamp.Tensor(Tensor self, Tensor? min=None, Tensor? max=None)`
-    ///
-    /// Unlike `clamp.default` (which takes Python scalar bounds), the `.Tensor`
-    /// overload takes tensor bounds that appear as separate input nodes in the
-    /// FX graph. PyTorch supports any NumPy-broadcastable bound shape:
-    ///
-    ///   - rank-0 (scalar wrapped in a tensor) — most common
-    ///   - same shape as self (per-element clamp, e.g. learned bounds)
-    ///   - any shape that broadcasts to self via right-align + size-1 expand
-    ///     (e.g. `(3, 1)` against `(3, 4)` for per-row clamp; `(4,)` against
-    ///     `(3, 4)` for per-column clamp; `(3, 4)` against `(2, 3, 4)`)
-    ///
-    /// We use `broadcast_binary` to right-align and expand both operands to a
-    /// common shape before the elementwise max/min, matching PyTorch semantics
-    /// across all three modes.
-    ///
-    /// Either bound may be absent (FX represents this as a non-tensor argument
-    /// at the corresponding input slot), in which case we clamp to one side
-    /// only.
-    pub(crate) fn translate_clamp_tensor(&mut self, node: &Node) -> Result<GraphTensor> {
-        let a = self.get_input_tensor(node, 0)?;
-        let min_tensor = node
-            .inputs
-            .get(1)
-            .and_then(|i| i.arg.as_tensor_name())
-            .map(|n| self.get_tensor(n))
-            .transpose()?;
-        let max_tensor = node
-            .inputs
-            .get(2)
-            .and_then(|i| i.arg.as_tensor_name())
-            .map(|n| self.get_tensor(n))
-            .transpose()?;
-
-        let mut result = a;
-        if let Some(lo) = min_tensor {
-            let lo = lo.cast(result.dtype);
-            let (r, lo) = broadcast_binary(result, lo);
-            result = r.maximum(lo);
-        }
-        if let Some(hi) = max_tensor {
-            let hi = hi.cast(result.dtype);
-            let (r, hi) = broadcast_binary(result, hi);
-            result = r.minimum(hi);
-        }
-        Ok(result)
-    }
 }

crates/luminal_python/src/luminal/__init__.py

@@ -8,12 +8,14 @@ from .compiled_model import CompiledModel
 # Import Rust extension components (built by maturin)
 from .luminal import CompiledGraph, process_pt2
 from .main import luminal_backend, register_backend
+from .pt2 import compile
 
 _register_cache_serialization()
 
 # Re-export everything for clean package interface
 __all__ = [
     "CompiledModel",
+    "compile",
     "luminal_backend",
     "register_backend",
     "CompiledGraph",

crates/luminal_python/src/luminal/compiled_model.py

@@ -1,9 +1,8 @@
 """CompiledModel wrapper for the Rust CompiledGraph."""
 
-from typing import List
+from typing import Any, List
 
 import torch
-
 from .dtype_util import code_to_torch_dtype
 from .dtype_util import torch_dtype_code as _torch_dtype_code
 
@@ -28,6 +27,14 @@ class CompiledModel:
         self._input_names = input_names or graph_result.input_names
         self._output_names = graph_result.output_names
         self._output_shapes = graph_result.output_shapes
+        output_dtype_codes = graph_result.output_dtypes
+        self._output_dtypes = [
+            code_to_torch_dtype(output_dtype_codes[i])
+            if i < len(output_dtype_codes)
+            else torch.float32
+            for i in range(len(self._output_names))
+        ]
+        self._static_output_shapes = [tuple(shape) for shape in self._output_shapes]
         self._has_dynamic_dims = getattr(graph_result, "has_dynamic_dims", False)
         self._weight_refs = weight_refs or []
         self._user_indices = user_indices
@@ -35,6 +42,9 @@ class CompiledModel:
         self._supports_device_ptrs = getattr(
             graph_result, "supports_device_ptrs", False
         )
+        # Cache converted/contiguous views for repeated calls with the same input
+        # tensors so we don't rebuild sparse index buffers every forward.
+        self._prepared_input_cache = [None] * len(self._input_names)
         # Expected input dtypes from graph (used to convert user inputs)
         input_dtype_codes = graph_result.input_dtypes
         self._input_dtypes = [
@@ -43,6 +53,80 @@ class CompiledModel:
             else torch.float32
             for i in range(len(self._input_names))
         ]
+        self._single_float_output_fast_path = (
+            self._supports_device_ptrs
+            and not self._has_dynamic_dims
+            and len(self._output_names) == 1
+            and self._output_dtypes[0].is_floating_point
+        )
+
+    @staticmethod
+    def _input_cache_key(tensor: torch.Tensor, expected_dtype: torch.dtype):
+        return (
+            id(tensor),
+            getattr(tensor, "_version", None),
+            tensor.data_ptr(),
+            expected_dtype,
+        )
+
+    def _prepare_input_tensor(
+        self, index: int, tensor: torch.Tensor, expected_dtype: torch.dtype
+    ) -> torch.Tensor:
+        detached = tensor.detach()
+        needs_preparation = (
+            detached.dtype != expected_dtype or not detached.is_contiguous()
+        )
+        if not needs_preparation:
+            return detached
+
+        cache_key = self._input_cache_key(detached, expected_dtype)
+        cached = self._prepared_input_cache[index]
+        if cached is not None and cached[0] == cache_key:
+            return cached[1]
+
+        prepared = detached.contiguous().to(expected_dtype)
+        self._prepared_input_cache[index] = (cache_key, prepared)
+        return prepared
+
+    def _bind_user_inputs(self, user_inputs: List[torch.Tensor]) -> List[torch.Tensor]:
+        """Bind the current user inputs into the Rust graph."""
+        input_refs = []
+        for index, (name, tensor, expected_dtype) in enumerate(
+            zip(self._input_names, user_inputs, self._input_dtypes)
+        ):
+            prepared = self._prepare_input_tensor(index, tensor, expected_dtype)
+            if self._supports_device_ptrs and tensor.is_cuda:
+                n_bytes = prepared.numel() * prepared.element_size()
+                self._graph.set_input_device_ptr(name, prepared.data_ptr(), n_bytes)
+                input_refs.append(prepared)
+            else:
+                if prepared.device.type != "cpu":
+                    prepared = prepared.cpu()
+                n_bytes = prepared.numel() * prepared.element_size()
+                dtype_code = _torch_dtype_code(prepared.dtype)
+                self._graph.set_input_from_ptr(
+                    name, prepared.data_ptr(), n_bytes, dtype_code
+                )
+        return input_refs
+
+    def _run_static_single_float_output(
+        self, user_inputs: List[torch.Tensor], input_device: torch.device
+    ):
+        _input_refs = self._bind_user_inputs(user_inputs)
+        output_name = self._output_names[0]
+        output_dtype = self._output_dtypes[0]
+        out = torch.empty(
+            self._static_output_shapes[0], dtype=output_dtype, device=input_device
+        )
+        self._graph.set_output_device_ptr(
+            output_name, out.data_ptr(), out.numel() * out.element_size()
+        )
+        self._graph.run()
+        if not self._graph.output_is_zero_copy(output_name):
+            self._graph.copy_output_to_device_ptr(
+                output_name, out.data_ptr(), out.numel() * out.element_size()
+            )
+        return (out,)
 
     def set_dim(self, param_name: str, value: int) -> None:
         """Set a dynamic dimension value by its param name."""
@@ -86,25 +170,18 @@ class CompiledModel:
         if self._has_dynamic_dims:
             input_shapes = [list(t.shape) for t in user_inputs]
             self._graph.auto_set_dims_from_input_shapes(input_shapes)
+        elif (
+            self._single_float_output_fast_path
+            and input_device.type != "cpu"
+            and all(torch.is_tensor(t) and t.is_cuda for t in user_inputs)
+        ):
+            return self._run_static_single_float_output(user_inputs, input_device)
 
         # Set user input data via pointer.
         # Convert to the graph's expected dtype so bytes match the Input node's dtype tag.
         # For CUDA inputs, keep references alive so the caching allocator doesn't
         # recycle GPU memory before run() reads the pointers.
-        _input_refs = []
-        for name, tensor, expected_dtype in zip(
-            self._input_names, user_inputs, self._input_dtypes
-        ):
-            if self._supports_device_ptrs and tensor.is_cuda:
-                t = tensor.detach().contiguous().to(expected_dtype)
-                n_bytes = t.numel() * t.element_size()
-                self._graph.set_input_device_ptr(name, t.data_ptr(), n_bytes)
-                _input_refs.append(t)
-            else:
-                t = tensor.detach().cpu().contiguous().to(expected_dtype)
-                n_bytes = t.numel() * t.element_size()
-                dtype_code = _torch_dtype_code(t.dtype)
-                self._graph.set_input_from_ptr(name, t.data_ptr(), n_bytes, dtype_code)
+        _input_refs = self._bind_user_inputs(user_inputs)
 
         # Resolve output shapes before run() (needed for pre-allocation).
         if self._has_dynamic_dims:
@@ -112,8 +189,6 @@ class CompiledModel:
         else:
             output_shapes = self._output_shapes
 
-        output_dtype_codes = self._graph.output_dtypes
-
         # CUDA zero-copy path: pre-allocate output tensors and register their device
         # pointers so the final kernel writes directly into PyTorch's buffer.
         _use_zero_copy = self._supports_device_ptrs
@@ -121,8 +196,8 @@ class CompiledModel:
         if _use_zero_copy:
             for i, (name, shape) in enumerate(zip(self._output_names, output_shapes)):
                 out_dtype = (
-                    code_to_torch_dtype(output_dtype_codes[i])
-                    if i < len(output_dtype_codes)
+                    self._output_dtypes[i]
+                    if i < len(self._output_dtypes)
                     else torch.float32
                 )
                 out = torch.empty(shape, dtype=out_dtype, device=input_device)
@@ -135,18 +210,13 @@ class CompiledModel:
         # Run the graph
         self._graph.run()
 
-        # Integer dtypes for which we read the buffer as i32 and then cast.
-        # Includes int64 because luminal collapses all integer types to its
-        # 32-bit `Int` internally — we restore the original precision here.
-        _int_dtypes = (torch.int8, torch.int16, torch.int32, torch.int64, torch.uint8)
-
         # Collect outputs
         if _use_zero_copy:
             outputs = []
             for i, (name, shape) in enumerate(zip(self._output_names, output_shapes)):
                 out_dtype = (
-                    code_to_torch_dtype(output_dtype_codes[i])
-                    if i < len(output_dtype_codes)
+                    self._output_dtypes[i]
+                    if i < len(self._output_dtypes)
                     else torch.float32
                 )
                 out = output_tensors[i]
@@ -155,12 +225,11 @@ class CompiledModel:
                         self._graph.copy_output_to_device_ptr(
                             name, out.data_ptr(), out.numel() * out.element_size()
                         )
-                elif out_dtype in _int_dtypes:
+                elif out_dtype == torch.int32:
                     data = self._graph.get_output_i32(name)
                     out = (
                         torch.tensor(data, dtype=torch.int32)
                         .reshape(tuple(shape))
-                        .to(out_dtype)
                         .to(input_device)
                     )
                 elif out_dtype == torch.bool:
@@ -184,17 +253,13 @@ class CompiledModel:
             outputs = []
             for i, (name, shape) in enumerate(zip(self._output_names, output_shapes)):
                 out_dtype = (
-                    code_to_torch_dtype(output_dtype_codes[i])
-                    if i < len(output_dtype_codes)
+                    self._output_dtypes[i]
+                    if i < len(self._output_dtypes)
                     else torch.float32
                 )
-                if out_dtype in _int_dtypes:
+                if out_dtype == torch.int32:
                     data = self._graph.get_output_i32(name)
-                    out = (
-                        torch.tensor(data, dtype=torch.int32)
-                        .reshape(tuple(shape))
-                        .to(out_dtype)
-                    )
+                    out = torch.tensor(data, dtype=torch.int32).reshape(tuple(shape))
                 elif out_dtype == torch.bool:
                     data = self._graph.get_output_bool(name)
                     out = torch.tensor(data, dtype=torch.bool).reshape(tuple(shape))
@@ -209,3 +274,41 @@ class CompiledModel:
                 outputs.append(out)
 
         return tuple(outputs)
+
+
+def _leaf_paths(tree: Any, prefix=()):
+    if torch.is_tensor(tree):
+        return [prefix]
+    if isinstance(tree, (list, tuple)):
+        paths = []
+        for idx, value in enumerate(tree):
+            paths.extend(_leaf_paths(value, prefix + (idx,)))
+        return paths
+    if isinstance(tree, dict):
+        paths = []
+        for key, value in tree.items():
+            paths.extend(_leaf_paths(value, prefix + (key,)))
+        return paths
+    return [prefix]
+
+
+def _follow_path(tree: Any, path):
+    value = tree
+    for key in path:
+        value = value[key]
+    return value
+
+
+class StructuredCompiledModel:
+    """Preserve a module's original nested input structure for direct PT2 compile()."""
+
+    def __init__(self, compiled_model, example_args):
+        self._compiled = compiled_model
+        self._leaf_paths = _leaf_paths(example_args)
+
+    def __getattr__(self, name):
+        return getattr(self._compiled, name)
+
+    def __call__(self, *args):
+        flat_inputs = [_follow_path(args, path) for path in self._leaf_paths]
+        return self._compiled(*flat_inputs)

crates/luminal_python/src/luminal/pt2.py

@@ -9,10 +9,12 @@ import inspect
 import os
 import shutil
 import tempfile
+from contextlib import contextmanager
 
 import torch
+import torch.utils._pytree as pytree
 
-from .compiled_model import CompiledModel
+from .compiled_model import CompiledModel, StructuredCompiledModel
 from .luminal import process_pt2
 from .main import _collect_weight_pointers, _detect_factory_capsule, _load_cpu_weights
 
@@ -184,6 +186,66 @@ def _save_and_compile(
             shutil.rmtree(tmpdir, ignore_errors=True)
 
 
+def _has_cuda_inputs(flat_example_inputs):
+    return any(torch.is_tensor(inp) and inp.is_cuda for inp in flat_example_inputs)
+
+
+def _direct_search_env(flat_example_inputs, search_trials=None, search_keep_best=None):
+    """Search env overrides for direct compile() calls.
+
+    CUDA DLRM-style models benefit materially from a deeper per-candidate
+    profile and from keeping more parents alive between generations. Keep the
+    defaults narrow so CPU and env-configured callers are unchanged.
+    """
+    has_cuda = _has_cuda_inputs(flat_example_inputs)
+    overrides = {}
+
+    if search_trials is not None:
+        overrides["LUMINAL_SEARCH_TRIALS"] = str(search_trials)
+    elif has_cuda and "LUMINAL_SEARCH_TRIALS" not in os.environ:
+        overrides["LUMINAL_SEARCH_TRIALS"] = "5"
+
+    if search_keep_best is not None:
+        overrides["LUMINAL_SEARCH_KEEP_BEST"] = str(search_keep_best)
+    elif has_cuda and "LUMINAL_SEARCH_KEEP_BEST" not in os.environ:
+        overrides["LUMINAL_SEARCH_KEEP_BEST"] = "3"
+
+    return overrides
+
+
+@contextmanager
+def _temporary_env(overrides):
+    sentinel = object()
+    previous = {}
+    try:
+        for key, value in overrides.items():
+            previous[key] = os.environ.get(key, sentinel)
+            os.environ[key] = value
+        yield
+    finally:
+        for key, old_value in previous.items():
+            if old_value is sentinel:
+                os.environ.pop(key, None)
+            else:
+                os.environ[key] = old_value
+
+
+def _strip_exported_weights_for_zero_copy(ep, original_weights):
+    """Shrink the saved .pt2 artifact when original weights will be reused."""
+    if not original_weights:
+        return
+    for key in list(ep._state_dict.keys()):
+        if key in original_weights:
+            orig = ep._state_dict[key]
+            replacement = torch.zeros(1, dtype=orig.dtype, device="cpu")
+            if isinstance(orig, torch.nn.Parameter):
+                replacement = torch.nn.Parameter(
+                    replacement, requires_grad=orig.requires_grad
+                )
+            ep._state_dict[key] = replacement
+            del orig
+
+
 def _safe_int_bound(value):
     """Coerce a sympy/symbolic-shape range bound to a finite int, or None.
 
@@ -401,7 +463,9 @@ def _reinternalize_lifted_params(gm, example_inputs):
 def compile(
     model,
     example_input,
-    search_iterations=25,
+    search_iterations=None,
+    search_trials=None,
+    search_keep_best=None,
     factory=None,
     export_kwargs=None,
     dynamic_dim=None,
@@ -413,7 +477,13 @@ def compile(
         model: A PyTorch nn.Module.
         example_input: Example input tensor — or a list/tuple of tensors for
             multi-input models.
-        search_iterations: Number of optimization search iterations.
+        search_iterations: Number of optimization search iterations. When None,
+            defaults to 200 on CUDA inputs and 10 otherwise.
+        search_trials: Optional per-candidate profiling trials inside Luminal's
+            search. When unset, direct CUDA compile defaults to 5.
+        search_keep_best: Optional number of parent candidates to retain
+            between search generations. When unset, direct CUDA compile
+            defaults to 3.
         factory: PyCapsule wrapping a BackendFactory. Auto-detected if None.
         export_kwargs: Extra kwargs passed to torch.export.export.
         dynamic_dim: Convenience controls for `dynamic_shapes` when only one
@@ -432,17 +502,26 @@ def compile(
     Returns:
         A CompiledModel callable.
     """
-    if factory is None:
-        factory = _detect_factory_capsule(
-            example_input
-            if isinstance(example_input, (list, tuple))
-            else [example_input]
-        )
-
     if isinstance(example_input, (list, tuple)):
         example_args = tuple(example_input)
     else:
         example_args = (example_input,)
+    flat_example_inputs = pytree.arg_tree_leaves(*example_args)
+
+    if factory is None:
+        factory = _detect_factory_capsule(flat_example_inputs)
+
+    if search_iterations is None:
+        search_iterations = (
+            200
+            if _has_cuda_inputs(flat_example_inputs)
+            else 10
+        )
+    search_env = _direct_search_env(
+        flat_example_inputs,
+        search_trials=search_trials,
+        search_keep_best=search_keep_best,
+    )
 
     kwargs = export_kwargs or {}
     extra = _export_kwargs()
@@ -488,63 +567,16 @@ def compile(
         )
         ep = ep.run_decompositions(_decomp_table())
 
-    return _save_and_compile(ep, factory, search_iterations)
-
-
-def _drop_input_guards(ep):
-    """Discard ``ep._guards_code`` so unlift does not emit a ``_guards_fn``.
-
-    LUM-499: When a 0-d int tensor flows into a tensor index (``x[i]`` with
-    ``i = torch.tensor(2)``), torch.export records two equivalent input
-    guards: ``L['i'].item() == 2`` (referencing the original local source)
-    and ``L['args'][1].item() == 2`` (referencing the rewrapped flat args).
-    Two failures stack on top of each other:
-
-    1. ``ep.module()`` (invoked inside ``run_decompositions``) rewrites
-       ``L['args'][1]`` → ``args[1]`` but cannot resolve ``L['i']``, leaving
-       a literal ``L`` reference in the generated ``_guards_fn`` and raising
-       ``NameError: name 'L' is not defined`` during retracing.
-    2. Even after dropping the unresolvable guard, the surviving
-       ``args[1].item()`` is data-dependent: AOT autograd's fake-tensor pass
-       raises ``DataDependentOutputException(_local_scalar_dense)``, forcing
-       a graph break.
-
-    These guards exist solely to validate inputs at runtime in eager-mode
-    consumers of the ExportedProgram; the luminal compiler does its own
-    input shape/dtype checks against the compiled graph signature, so we
-    are not losing any safety by clearing them.
-    """
-
-    if hasattr(ep, "_guards_code"):
-        ep._guards_code = []
-
-
-def _drop_dead_data_dependent_ops(gm):
-    """Remove ``aten.item.default`` (and other data-dependent ops) with no users.
-
-    When dynamo specializes a 0-d int input by tracing through ``.item()``,
-    the resulting graph may contain a dead ``aten.item.default`` node whose
-    output is never consumed. luminal's translator does not lower
-    ``aten._local_scalar_dense`` / ``aten.item.default``, so leaving the dead
-    node in the graph causes a graph break at compile time. Eliminating it
-    keeps the (correctly specialized) downstream graph in a single subgraph.
-    """
-
-    graph = gm.graph
-    changed = False
-    for node in list(graph.nodes):
-        if (
-            node.op == "call_function"
-            and getattr(node.target, "_overloadpacket", None) is torch.ops.aten.item
-            and len(node.users) == 0
-        ):
-            graph.erase_node(node)
-            changed = True
-
-    if changed:
-        graph.eliminate_dead_code()
-        graph.lint()
-        gm.recompile()
+    original_weights = model.state_dict()
+    _strip_exported_weights_for_zero_copy(ep, original_weights)
+    with _temporary_env(search_env):
+        compiled = _save_and_compile(
+            ep,
+            factory,
+            search_iterations,
+            original_weights=original_weights,
+        )
+    return StructuredCompiledModel(compiled, example_args)
 
 
 def _legacy_auto_dim(example_args):
@@ -626,23 +658,13 @@ def _eager_pt2_compile(
         if dynamic_shapes is None:
             raise
         ep = torch.export.export(gm, tuple(user_inputs), **_export_kwargs())
-    # LUM-499: drop dynamo-emitted input guards before run_decompositions
-    # calls ep.module(), which would otherwise emit a `_guards_fn` containing
-    # data-dependent .item() calls and unresolved `L[...]` references.
-    _drop_input_guards(ep)
-    _drop_dead_data_dependent_ops(ep.graph_module)
     ep = ep.run_decompositions(_decomp_table())
 
     # When using shared memory (original_weights), strip large weight buffers
     # from the EP before saving. The Rust side uses device pointers for these
     # weights, not the .pt2 file data, so serializing them is pure IO waste
     # (~32 GB for 8B models). Replace with tiny CPU scalars to shrink to <1 MB.
-    if original_weights:
-        for key in list(ep._state_dict.keys()):
-            if key in original_weights:
-                orig = ep._state_dict[key]
-                ep._state_dict[key] = torch.zeros(1, dtype=orig.dtype, device="cpu")
-                del orig
+    _strip_exported_weights_for_zero_copy(ep, original_weights)
 
     # Save EP to disk, then free it and the traced graph module before Rust
     # compilation. torch.export clones the state_dict internally; holding ep
@@ -656,11 +678,20 @@ def _eager_pt2_compile(
     if torch.cuda.is_available():
         torch.cuda.empty_cache()
 
+    default_search_iterations = (
+        50
+        if any(torch.is_tensor(inp) and inp.is_cuda for inp in user_inputs)
+        else 10
+    )
+    search_iterations = int(
+        os.environ.get("LUMINAL_PT2_SEARCH_ITERATIONS", str(default_search_iterations))
+    )
+
     try:
         return _save_and_compile(
             pt2_path,
             factory,
-            10,
+            search_iterations,
             original_weights=original_weights,
             user_indices=user_indices,
         )

crates/luminal_python/tests/for_jake.md

@@ -0,0 +1,11 @@
+# DLRM CUDA Benchmark
+
+These numbers are from the focused `2048`-candidate DLRM CUDA benchmark in
+`test_dlrm.py`, measured after compile and warmup with `5 x 20` timed runs.
+
+| Path | Median latency | Throughput |
+| --- | ---: | ---: |
+| eager | 0.267 ms | 7,674,321 candidates/s |
+| torch.compile + inductor | 0.295 ms | 6,933,911 candidates/s |
+| torch.compile + inductor (`reduce-overhead`) | 0.299 ms | 6,843,456 candidates/s |
+| torch.compile + `luminal_backend` | 0.476 ms | 4,299,775 candidates/s |

crates/luminal_python/tests/test_deepctr_torch.py

@@ -0,0 +1,213 @@
+"""DeepCTR-Torch DCN / DIN coverage for the luminal torch.compile backend.
+
+These tests are intended for the local integration workflow where the
+``DeepCTR-Torch`` repo is checked out next to ``luminal``. They first confirm
+that eager mode and regular ``torch.compile(..., backend="inductor")`` agree,
+then run the same model through ``backend=luminal_backend``.
+"""
+
+from __future__ import annotations
+
+import copy
+import sys
+from contextlib import contextmanager
+from pathlib import Path
+
+import numpy as np
+import pytest
+import torch
+
+pytest.importorskip("sklearn")
+pytest.importorskip("tqdm")
+
+DEEPCTR_ROOT = Path(__file__).resolve().parents[4] / "DeepCTR-Torch"
+if not DEEPCTR_ROOT.exists():
+    pytest.skip(
+        f"DeepCTR-Torch checkout not found at {DEEPCTR_ROOT}",
+        allow_module_level=True,
+    )
+
+deepctr_root = str(DEEPCTR_ROOT)
+if deepctr_root not in sys.path:
+    sys.path.insert(0, deepctr_root)
+
+from deepctr_torch.inputs import (
+    DenseFeat,
+    SparseFeat,
+    VarLenSparseFeat,
+    build_input_features,
+)
+from deepctr_torch.models import DCN
+from deepctr_torch.models.din import DIN
+from luminal import luminal_backend
+
+
+def _stack_features(
+    feature_columns: list, feature_dict: dict[str, np.ndarray], device: torch.device
+) -> torch.Tensor:
+    parts = []
+    for name in build_input_features(feature_columns):
+        value = np.asarray(feature_dict[name])
+        if value.ndim == 1:
+            value = np.expand_dims(value, axis=1)
+        parts.append(value)
+    stacked = np.concatenate(parts, axis=-1)
+    return torch.tensor(stacked, dtype=torch.float32, device=device)
+
+
+def _unwrap(output: torch.Tensor | tuple[torch.Tensor, ...]) -> torch.Tensor:
+    if isinstance(output, tuple) and len(output) == 1:
+        return output[0]
+    return output
+
+
+def _assert_allclose(
+    lhs: torch.Tensor, rhs: torch.Tensor, label: str, atol: float = 1e-5
+) -> None:
+    max_diff = torch.max(torch.abs(lhs - rhs)).item()
+    assert torch.allclose(lhs, rhs, atol=atol), f"{label} max_diff={max_diff:.2e}"
+
+
+def _run_eager(model: torch.nn.Module, *inputs: torch.Tensor) -> torch.Tensor:
+    with torch.no_grad():
+        return _unwrap(model(*inputs))
+
+
+@contextmanager
+def _relaxed_dynamo_limits():
+    prev_recompile_limit = torch._dynamo.config.recompile_limit
+    prev_cache_size_limit = torch._dynamo.config.cache_size_limit
+    torch._dynamo.config.recompile_limit = 16
+    torch._dynamo.config.cache_size_limit = 16
+    try:
+        yield
+    finally:
+        torch._dynamo.config.recompile_limit = prev_recompile_limit
+        torch._dynamo.config.cache_size_limit = prev_cache_size_limit
+
+
+def _run_inductor(model: torch.nn.Module, *inputs: torch.Tensor) -> torch.Tensor:
+    with _relaxed_dynamo_limits():
+        torch._dynamo.reset()
+        compiled = torch.compile(copy.deepcopy(model), backend="inductor")
+        with torch.no_grad():
+            return _unwrap(compiled(*inputs))
+
+
+def _run_luminal(model: torch.nn.Module, *inputs: torch.Tensor) -> torch.Tensor:
+    with _relaxed_dynamo_limits():
+        torch._dynamo.reset()
+        compiled = torch.compile(copy.deepcopy(model), backend=luminal_backend)
+        with torch.no_grad():
+            return _unwrap(compiled(*inputs))
+
+
+def _make_dcn(
+    device: torch.device, cross_parameterization: str
+) -> tuple[torch.nn.Module, tuple[torch.Tensor]]:
+    torch.manual_seed(0)
+    feature_columns = [
+        SparseFeat("s0", 5, embedding_dim=4),
+        SparseFeat("s1", 7, embedding_dim=4),
+        DenseFeat("d0", 1),
+        DenseFeat("d1", 1),
+    ]
+    feature_dict = {
+        "s0": np.array([0, 1, 2, 3], dtype=np.int64),
+        "s1": np.array([1, 2, 3, 4], dtype=np.int64),
+        "d0": np.array([0.1, 0.2, 0.3, 0.4], dtype=np.float32),
+        "d1": np.array([1.0, 0.0, 1.0, 0.0], dtype=np.float32),
+    }
+    model = DCN(
+        linear_feature_columns=feature_columns,
+        dnn_feature_columns=feature_columns,
+        cross_num=2,
+        cross_parameterization=cross_parameterization,
+        dnn_hidden_units=(16,),
+        dnn_dropout=0.0,
+        device=str(device),
+    ).eval()
+    inputs = (_stack_features(feature_columns, feature_dict, device),)
+    return model.to(device), inputs
+
+
+def _make_din(device: torch.device) -> tuple[torch.nn.Module, tuple[torch.Tensor]]:
+    torch.manual_seed(0)
+    feature_columns = [
+        SparseFeat("user", 4, embedding_dim=4),
+        SparseFeat("gender", 2, embedding_dim=4),
+        SparseFeat("item_id", 4, embedding_dim=8),
+        SparseFeat("cate_id", 3, embedding_dim=4),
+        DenseFeat("pay_score", 1),
+        VarLenSparseFeat(
+            SparseFeat(
+                "hist_item_id",
+                vocabulary_size=4,
+                embedding_dim=8,
+                embedding_name="item_id",
+            ),
+            maxlen=4,
+            length_name="seq_length",
+        ),
+        VarLenSparseFeat(
+            SparseFeat(
+                "hist_cate_id",
+                vocabulary_size=3,
+                embedding_dim=4,
+                embedding_name="cate_id",
+            ),
+            maxlen=4,
+            length_name="seq_length",
+        ),
+    ]
+    feature_dict = {
+        "user": np.array([0, 1, 2, 3], dtype=np.int64),
+        "gender": np.array([0, 1, 0, 1], dtype=np.int64),
+        "item_id": np.array([1, 2, 3, 2], dtype=np.int64),
+        "cate_id": np.array([1, 2, 1, 2], dtype=np.int64),
+        "pay_score": np.array([0.1, 0.2, 0.3, 0.2], dtype=np.float32),
+        "hist_item_id": np.array(
+            [[1, 2, 3, 0], [1, 2, 3, 0], [1, 2, 0, 0], [1, 2, 0, 0]],
+            dtype=np.int64,
+        ),
+        "hist_cate_id": np.array(
+            [[1, 1, 2, 0], [2, 1, 1, 0], [2, 1, 0, 0], [1, 2, 0, 0]],
+            dtype=np.int64,
+        ),
+        "seq_length": np.array([3, 3, 2, 2], dtype=np.int64),
+    }
+    model = DIN(
+        feature_columns,
+        ["item_id", "cate_id"],
+        dnn_dropout=0.0,
+        device=str(device),
+    ).eval()
+    inputs = (_stack_features(feature_columns, feature_dict, device),)
+    return model.to(device), inputs
+
+
+@pytest.mark.parametrize("cross_parameterization", ["vector", "matrix"])
+def test_deepctr_dcn_matches_inductor_when_supported(
+    device: torch.device, cross_parameterization: str
+) -> None:
+    model, inputs = _make_dcn(device, cross_parameterization)
+
+    eager = _run_eager(model, *inputs)
+    inductor = _run_inductor(model, *inputs)
+    _assert_allclose(inductor, eager, "inductor vs eager")
+
+    luminal = _run_luminal(model, *inputs)
+    _assert_allclose(luminal, eager, "luminal vs eager")
+    _assert_allclose(luminal, inductor, "luminal vs inductor")
+
+
+def test_deepctr_din_matches_inductor_when_supported(device: torch.device) -> None:
+    model, inputs = _make_din(device)
+
+    eager = _run_eager(model, *inputs)
+    inductor = _run_inductor(model, *inputs)
+    _assert_allclose(inductor, eager, "inductor vs eager")
+
+    luminal = _run_luminal(model, *inputs)
+    _assert_allclose(luminal, eager, "luminal vs eager")
+    _assert_allclose(luminal, inductor, "luminal vs inductor")

crates/luminal_python/tests/test_dlrm.py

@@ -0,0 +1,456 @@
+"""DLRM coverage for the luminal torch.compile backend.
+
+This test expects a sibling ``dlrm`` checkout next to ``luminal`` and validates
+that eager mode, ``torch.compile(..., backend="inductor")``, and
+``torch.compile(..., backend=luminal_backend)`` agree on deterministic DLRM
+configurations, including a CUDA benchmark that compares Luminal against
+TorchInductor's CUDA-graph-enabled ``mode="reduce-overhead"`` path.
+"""
+
+from __future__ import annotations
+
+import copy
+import importlib.machinery
+import sys
+import types
+from contextlib import contextmanager
+from pathlib import Path
+
+import numpy as np
+import pytest
+import torch
+
+pytest.importorskip("sklearn")
+
+DLRM_ROOT = Path(__file__).resolve().parents[4] / "dlrm"
+if not DLRM_ROOT.exists():
+    pytest.skip(f"dlrm checkout not found at {DLRM_ROOT}", allow_module_level=True)
+
+dlrm_root = str(DLRM_ROOT)
+if dlrm_root not in sys.path:
+    sys.path.insert(0, dlrm_root)
+
+
+def _install_dlrm_import_stubs() -> None:
+    ext_dist = types.ModuleType("extend_distributed")
+    ext_dist.my_size = 1
+    ext_dist.dist = None
+    ext_dist.get_split_lengths = lambda n: (n, [n])
+    ext_dist.get_my_slice = lambda n: slice(0, n)
+
+    class _AllToAll:
+        def __init__(self, values):
+            self._values = values
+
+        def wait(self):
+            return self._values
+
+    ext_dist.alltoall = lambda values, n_emb_per_rank: _AllToAll(values)
+    ext_dist.__spec__ = importlib.machinery.ModuleSpec(
+        "extend_distributed", loader=None
+    )
+    sys.modules["extend_distributed"] = ext_dist
+
+    mlperf_logger = types.ModuleType("mlperf_logger")
+    mlperf_logger.__spec__ = importlib.machinery.ModuleSpec(
+        "mlperf_logger", loader=None
+    )
+    sys.modules["mlperf_logger"] = mlperf_logger
+
+    tensorboard = types.ModuleType("torch.utils.tensorboard")
+
+    class SummaryWriter:
+        def __init__(self, *args, **kwargs):
+            pass
+
+        def add_scalar(self, *args, **kwargs):
+            pass
+
+        def close(self):
+            pass
+
+    tensorboard.SummaryWriter = SummaryWriter
+    tensorboard.__spec__ = importlib.machinery.ModuleSpec(
+        "torch.utils.tensorboard", loader=None
+    )
+    sys.modules["torch.utils.tensorboard"] = tensorboard
+
+    onnx = types.ModuleType("onnx")
+    onnx.__spec__ = importlib.machinery.ModuleSpec("onnx", loader=None)
+    sys.modules["onnx"] = onnx
+
+
+_install_dlrm_import_stubs()
+
+import dlrm_s_pytorch as dlrm_mod
+from luminal import luminal_backend
+
+dlrm_mod.args = types.SimpleNamespace(loss_weights="1-1", loss_function="bce")
+
+
+def _unwrap(output: torch.Tensor | tuple[torch.Tensor, ...]) -> torch.Tensor:
+    if isinstance(output, tuple) and len(output) == 1:
+        return output[0]
+    return output
+
+
+def _assert_allclose(
+    lhs: torch.Tensor, rhs: torch.Tensor, label: str, atol: float = 1e-5
+) -> None:
+    max_diff = torch.max(torch.abs(lhs - rhs)).item()
+    assert torch.allclose(lhs, rhs, atol=atol), f"{label} max_diff={max_diff:.2e}"
+
+
+def _run_eager(model: torch.nn.Module, *inputs) -> torch.Tensor:
+    with torch.no_grad():
+        return _unwrap(model(*inputs))
+
+
+@contextmanager
+def _relaxed_dynamo_limits():
+    prev_recompile_limit = torch._dynamo.config.recompile_limit
+    prev_cache_size_limit = torch._dynamo.config.cache_size_limit
+    torch._dynamo.config.recompile_limit = 16
+    torch._dynamo.config.cache_size_limit = 16
+    try:
+        yield
+    finally:
+        torch._dynamo.config.recompile_limit = prev_recompile_limit
+        torch._dynamo.config.cache_size_limit = prev_cache_size_limit
+
+
+def _run_inductor(model: torch.nn.Module, *inputs) -> torch.Tensor:
+    with _relaxed_dynamo_limits():
+        torch._dynamo.reset()
+        compiled = torch.compile(copy.deepcopy(model), backend="inductor")
+        with torch.no_grad():
+            return _unwrap(compiled(*inputs))
+
+
+def _compile_inductor(model: torch.nn.Module):
+    with _relaxed_dynamo_limits():
+        torch._dynamo.reset()
+        return torch.compile(copy.deepcopy(model), backend="inductor")
+
+
+def _run_luminal(model: torch.nn.Module, *inputs) -> torch.Tensor:
+    with _relaxed_dynamo_limits():
+        torch._dynamo.reset()
+        compiled = torch.compile(copy.deepcopy(model), backend=luminal_backend)
+        with torch.no_grad():
+            return _unwrap(compiled(*inputs))
+
+
+def _compile_inductor_reduce_overhead(model: torch.nn.Module):
+    with _relaxed_dynamo_limits():
+        torch._dynamo.reset()
+        return torch.compile(
+            copy.deepcopy(model),
+            backend="inductor",
+            mode="reduce-overhead",
+        )
+
+
+def _compile_luminal(model: torch.nn.Module):
+    with _relaxed_dynamo_limits():
+        torch._dynamo.reset()
+        return torch.compile(copy.deepcopy(model), backend=luminal_backend)
+
+
+def _timed_cuda_runs(
+    compiled_model,
+    *inputs,
+    warmup_iters: int,
+    timed_iters: int,
+    mark_step_begin: bool = False,
+) -> dict[str, float]:
+    assert torch.cuda.is_available(), "CUDA timing requires an available GPU"
+
+    with torch.no_grad():
+        for _ in range(warmup_iters):
+            if mark_step_begin:
+                torch.compiler.cudagraph_mark_step_begin()
+            _unwrap(compiled_model(*inputs))
+
+    torch.cuda.synchronize()
+    starts = [torch.cuda.Event(enable_timing=True) for _ in range(timed_iters)]
+    ends = [torch.cuda.Event(enable_timing=True) for _ in range(timed_iters)]
+
+    with torch.no_grad():
+        for idx in range(timed_iters):
+            if mark_step_begin:
+                torch.compiler.cudagraph_mark_step_begin()
+            starts[idx].record()
+            _unwrap(compiled_model(*inputs))
+            ends[idx].record()
+
+    torch.cuda.synchronize()
+    elapsed_ms = np.array(
+        [start.elapsed_time(end) for start, end in zip(starts, ends)],
+        dtype=np.float64,
+    )
+    return {
+        "mean_ms": float(elapsed_ms.mean()),
+        "median_ms": float(np.median(elapsed_ms)),
+        "min_ms": float(elapsed_ms.min()),
+    }
+
+
+def _timed_cuda_rounds(
+    compiled_model,
+    *inputs,
+    pre_round_warmup_iters: int,
+    timed_iters: int,
+    rounds: int,
+    mark_step_begin: bool = False,
+) -> dict[str, float | list[float]]:
+    assert rounds > 0, "rounds must be positive"
+
+    stats = _timed_cuda_runs(
+        compiled_model,
+        *inputs,
+        warmup_iters=pre_round_warmup_iters,
+        timed_iters=timed_iters,
+        mark_step_begin=mark_step_begin,
+    )
+    round_medians = [stats["median_ms"]]
+
+    for _ in range(rounds - 1):
+        stats = _timed_cuda_runs(
+            compiled_model,
+            *inputs,
+            warmup_iters=0,
+            timed_iters=timed_iters,
+            mark_step_begin=mark_step_begin,
+        )
+        round_medians.append(stats["median_ms"])
+
+    round_medians_np = np.array(round_medians, dtype=np.float64)
+    return {
+        "round_medians_ms": [float(value) for value in round_medians],
+        "median_ms": float(np.median(round_medians_np)),
+        "mean_ms": float(round_medians_np.mean()),
+        "min_ms": float(round_medians_np.min()),
+    }
+
+
+def _make_dlrm(
+    device: torch.device,
+) -> tuple[torch.nn.Module, tuple[torch.Tensor, list[torch.Tensor], list[torch.Tensor]]]:
+    np.random.seed(0)
+    torch.manual_seed(0)
+
+    m_spa = 4
+    ln_emb = np.array([8, 6, 4])
+    ln_bot = np.array([3, 4])
+    num_fea = ln_emb.size + 1
+    num_int = (num_fea * (num_fea - 1)) // 2 + m_spa
+    ln_top = np.array([num_int, 8, 1])
+
+    model = dlrm_mod.DLRM_Net(
+        m_spa=m_spa,
+        ln_emb=ln_emb,
+        ln_bot=ln_bot,
+        ln_top=ln_top,
+        arch_interaction_op="dot",
+        arch_interaction_itself=False,
+        sigmoid_top=1,
+    ).eval()
+
+    inputs = (
+        torch.tensor([[0.1, 0.2, 0.3], [0.4, 0.5, 0.6]], dtype=torch.float32, device=device),
+        [
+            torch.tensor([0, 1], dtype=torch.int64, device=device),
+            torch.tensor([0, 1], dtype=torch.int64, device=device),
+            torch.tensor([0, 1], dtype=torch.int64, device=device),
+        ],
+        [
+            torch.tensor([1, 2], dtype=torch.int64, device=device),
+            torch.tensor([0, 3], dtype=torch.int64, device=device),
+            torch.tensor([2, 1], dtype=torch.int64, device=device),
+        ],
+    )
+    return model.to(device), inputs
+
+
+def _make_dlrm_batch_2048(
+    device: torch.device,
+) -> tuple[torch.nn.Module, tuple[torch.Tensor, list[torch.Tensor], list[torch.Tensor]]]:
+    np.random.seed(0)
+    torch.manual_seed(0)
+
+    batch_size = 2048
+    indices_per_bag = 2
+    m_spa = 16
+    ln_emb = np.array([4096, 2048, 1024])
+    ln_bot = np.array([3, 64, m_spa])
+    num_fea = ln_emb.size + 1
+    num_int = (num_fea * (num_fea - 1)) // 2 + m_spa
+    ln_top = np.array([num_int, 64, 32, 1])
+
+    model = dlrm_mod.DLRM_Net(
+        m_spa=m_spa,
+        ln_emb=ln_emb,
+        ln_bot=ln_bot,
+        ln_top=ln_top,
+        arch_interaction_op="dot",
+        arch_interaction_itself=False,
+        sigmoid_top=2,
+    ).eval()
+
+    dense_x = torch.linspace(
+        -1.0,
+        1.0,
+        steps=batch_size * 3,
+        dtype=torch.float32,
+        device=device,
+    ).reshape(batch_size, 3)
+
+    total_sparse_indices = batch_size * indices_per_bag
+    positions = torch.arange(total_sparse_indices, dtype=torch.int64, device=device)
+    offsets = torch.arange(
+        0,
+        total_sparse_indices,
+        indices_per_bag,
+        dtype=torch.int64,
+        device=device,
+    )
+
+    inputs = (
+        dense_x,
+        [offsets.clone(), offsets.clone(), offsets.clone()],
+        [
+            ((positions * 3 + 1) % int(ln_emb[0])).to(torch.int64),
+            ((positions * 5 + 2) % int(ln_emb[1])).to(torch.int64),
+            ((positions * 7 + 3) % int(ln_emb[2])).to(torch.int64),
+        ],
+    )
+    return model.to(device), inputs
+
+
+def test_dlrm_matches_inductor_and_luminal(device: torch.device) -> None:
+    model, inputs = _make_dlrm(device)
+
+    eager = _run_eager(model, *inputs)
+    inductor = _run_inductor(model, *inputs)
+    _assert_allclose(inductor, eager, "inductor vs eager")
+
+    luminal = _run_luminal(model, *inputs)
+    _assert_allclose(luminal, eager, "luminal vs eager")
+    _assert_allclose(luminal, inductor, "luminal vs inductor")
+
+
+@pytest.mark.slow
+def test_dlrm_batch_2048_cuda_matches_torchinductor_reduce_overhead_and_reports_speed(
+    device: torch.device,
+) -> None:
+    if device.type != "cuda":
+        pytest.skip("Requires `LUMINAL_TEST_DEVICE=cuda` for the CUDA benchmark")
+
+    model, inputs = _make_dlrm_batch_2048(device)
+
+    eager = _run_eager(model, *inputs)
+
+    eager_model = copy.deepcopy(model).to(device).eval()
+    inductor_compiled = _compile_inductor(model)
+    inductor_reduce_overhead = _compile_inductor_reduce_overhead(model)
+    torch.compiler.cudagraph_mark_step_begin()
+    with torch.no_grad():
+        inductor_output = _unwrap(inductor_reduce_overhead(*inputs))
+
+    luminal_compiled = _compile_luminal(model)
+    with torch.no_grad():
+        luminal_output = _unwrap(luminal_compiled(*inputs))
+
+    with torch.no_grad():
+        inductor_default_output = _unwrap(inductor_compiled(*inputs))
+
+    _assert_allclose(inductor_default_output, eager, "inductor default vs eager", atol=1e-4)
+    _assert_allclose(inductor_output, eager, "inductor reduce-overhead vs eager", atol=1e-4)
+    _assert_allclose(luminal_output, eager, "luminal vs eager", atol=1e-4)
+    _assert_allclose(
+        luminal_output,
+        inductor_default_output,
+        "luminal vs inductor default",
+        atol=1e-4,
+    )
+    _assert_allclose(
+        luminal_output,
+        inductor_output,
+        "luminal vs inductor reduce-overhead",
+        atol=1e-4,
+    )
+
+    benchmark_rounds = 5
+    benchmark_iters = 20
+    post_compile_warmup_iters = 10
+
+    eager_stats = _timed_cuda_rounds(
+        eager_model,
+        *inputs,
+        pre_round_warmup_iters=post_compile_warmup_iters,
+        timed_iters=benchmark_iters,
+        rounds=benchmark_rounds,
+    )
+    inductor_default_stats = _timed_cuda_rounds(
+        inductor_compiled,
+        *inputs,
+        pre_round_warmup_iters=post_compile_warmup_iters,
+        timed_iters=benchmark_iters,
+        rounds=benchmark_rounds,
+    )
+    inductor_stats = _timed_cuda_rounds(
+        inductor_reduce_overhead,
+        *inputs,
+        pre_round_warmup_iters=post_compile_warmup_iters,
+        timed_iters=benchmark_iters,
+        rounds=benchmark_rounds,
+        mark_step_begin=True,
+    )
+    luminal_stats = _timed_cuda_rounds(
+        luminal_compiled,
+        *inputs,
+        pre_round_warmup_iters=post_compile_warmup_iters,
+        timed_iters=benchmark_iters,
+        rounds=benchmark_rounds,
+    )
+
+    batch_size = inputs[0].shape[0]
+    benchmark_results = [
+        ("eager", eager_stats),
+        ("inductor default", inductor_default_stats),
+        ("inductor reduce-overhead", inductor_stats),
+        ("luminal backend", luminal_stats),
+    ]
+    ranked_results = sorted(
+        benchmark_results,
+        key=lambda item: float(item[1]["median_ms"]),
+    )
+    speed_lines = []
+    for idx, (label, stats) in enumerate(ranked_results, start=1):
+        throughput = batch_size / (float(stats["median_ms"]) / 1000.0)
+        rounds_repr = ", ".join(
+            f"{value:.3f}" for value in stats["round_medians_ms"]  # type: ignore[index]
+        )
+        speed_lines.append(
+            f"  {idx}. {label}: {float(stats['median_ms']):.3f} ms"
+            f" ({throughput:,.0f} candidates/s)"
+            f" [round medians: {rounds_repr}]"
+        )
+
+    luminal_vs_inductor = float(luminal_stats["median_ms"]) / float(
+        inductor_stats["median_ms"]
+    )
+    luminal_vs_eager = float(luminal_stats["median_ms"]) / float(eager_stats["median_ms"])
+
+    print(
+        "\n"
+        f"DLRM batch={batch_size} candidates on CUDA after compile/warmup\n"
+        f"  Timed rounds: {benchmark_rounds} x {benchmark_iters} iterations\n"
+        f"  Ranking by median latency:\n"
+        + "\n".join(speed_lines)
+        + "\n"
+        f"  Luminal backend / TorchInductor reduce-overhead latency ratio:"
+        f" {luminal_vs_inductor:.3f}x\n"
+        f"  Luminal backend / eager latency ratio: {luminal_vs_eager:.3f}x"
+    )

crates/luminal_python/tests/test_hlir_ops.py

@@ -1,6 +1,5 @@
 from typing import Callable
 
-import pytest
 import torch
 import torch._dynamo
 from test_models import (
@@ -221,7 +220,6 @@ from test_models import (
     Conv1dNoPadModel,
     Conv1dSamePadModel,
     Conv1dBiasModel,
-    Conv1dFloorDivPositionalModel,
     Conv2dNoPadModel,
     Conv2dSamePadModel,
     Conv2dBiasModel,
@@ -1098,17 +1096,6 @@ def test_reduce_sum_all_axes(device: torch.device):
     assert torch.allclose(model_compiled(x), model(x), atol=1e-5)
 
 
-def test_reduce_sum_all_axes_int64_preserves_dtype(device: torch.device):
-    """Full reduction of an int64 tensor must preserve int64 (regression for LUM-486)."""
-    model: torch.nn.Module = ReduceSumAllAxesModel().to(device)
-    model_compiled: Callable = torch.compile(model, backend=luminal_backend)
-    x: torch.Tensor = torch.randint(0, 10, (3, 4), device=device, dtype=torch.int64)
-    eager = model(x)
-    out = model_compiled(x)
-    assert out.dtype == eager.dtype == torch.int64
-    assert torch.equal(out, eager)
-
-
 def test_reduce_sum_3d_axis1(device: torch.device):
     """Test sum reduction along axis 1 for a 3D tensor."""
     model: torch.nn.Module = ReduceSum3DAxis1Model().to(device)
@@ -2035,16 +2022,9 @@ def test_split(device: torch.device):
 # ========== Argsort / MoE Routing Tests ==========
 
 
-@pytest.mark.parametrize("idx_dtype", [torch.int32, torch.int64])
-def test_argsort_stable_duplicates(device: torch.device, idx_dtype: torch.dtype):
-    """Duplicate values should follow stable lower-index-first tie-breaking.
-
-    Parametrized over int32/int64 to verify luminal preserves whichever
-    integer dtype the eager model declares (LUM-486).
-    """
-    model: torch.nn.Module = ArgsortStableDuplicatesModel(idx_dtype=idx_dtype).to(
-        device
-    )
+def test_argsort_stable_duplicates(device: torch.device):
+    """Duplicate values should follow stable lower-index-first tie-breaking."""
+    model: torch.nn.Module = ArgsortStableDuplicatesModel().to(device)
     model_compiled: Callable = torch.compile(model, backend=luminal_backend)
     x = torch.tensor(
         [[2.0, 1.0, 1.0, 3.0]],
@@ -2053,21 +2033,13 @@ def test_argsort_stable_duplicates(device: torch.device, idx_dtype: torch.dtype)
     )
     original: torch.Tensor = model(x)
     output: torch.Tensor = model_compiled(x)
-    assert original.dtype == idx_dtype, "test setup: model should cast to idx_dtype"
-    assert output.dtype == original.dtype, (
-        f"luminal returned {output.dtype}, eager produced {original.dtype}"
-    )
-    assert torch.equal(output, original)
+    assert output.dtype == torch.int32
+    assert torch.equal(output, original.to(torch.int32))
 
 
-@pytest.mark.parametrize("idx_dtype", [torch.int32, torch.int64])
-def test_tiny_moe_routing(device: torch.device, idx_dtype: torch.dtype):
-    """Focused proof for built MoE routing support.
-
-    Parametrized over int32/int64 for the integer-valued outputs to verify
-    luminal preserves the dtype declared by the eager model (LUM-486).
-    """
-    model: torch.nn.Module = TinyMoERoutingModel(idx_dtype=idx_dtype).to(device)
+def test_tiny_moe_routing(device: torch.device):
+    """Focused proof for build MoE routing support."""
+    model: torch.nn.Module = TinyMoERoutingModel().to(device)
     model_compiled: Callable = torch.compile(model, backend=luminal_backend)
     scores = torch.tensor(
         [[0.1, 0.9, 0.4, 0.7], [0.6, -0.8, 0.95, 0.2]],
@@ -2078,10 +2050,17 @@ def test_tiny_moe_routing(device: torch.device, idx_dtype: torch.dtype):
     expected = model(scores)
     output = model_compiled(scores)
 
-    for actual, eager in zip(output, expected):
-        assert actual.dtype == eager.dtype, (
-            f"luminal returned {actual.dtype}, eager produced {eager.dtype}"
-        )
+    expected_dtypes = (
+        torch.int32,
+        torch.float32,
+        torch.int32,
+        torch.bool,
+        torch.int32,
+        torch.float32,
+    )
+    for actual, eager, expected_dtype in zip(output, expected, expected_dtypes):
+        assert actual.dtype == expected_dtype
+        eager = eager.to(actual.dtype)
         if actual.dtype.is_floating_point:
             assert torch.allclose(actual, eager)
         else:
@@ -2498,17 +2477,6 @@ def test_conv1d_bias(device: torch.device):
     assert torch.allclose(output, original, atol=1e-4)
 
 
-def test_conv1d_floor_div_positional_pt2(device: torch.device):
-    """Conv1d stride output uses floor division before positional add."""
-    model: torch.nn.Module = Conv1dFloorDivPositionalModel().to(device)
-    model_compiled: Callable = _compile_for_export_mode(model, "pt2")
-    x: torch.Tensor = torch.randn(1, 8, 30, device=device)
-    original: torch.Tensor = model(x)
-    output: torch.Tensor = model_compiled(x)
-    assert output.shape == original.shape == (15, 16)
-    assert torch.allclose(output, original, atol=1e-3, rtol=1e-3)
-
-
 def _run_conv2d_no_pad(device: torch.device, export_mode: str | None = None):
     """Conv2d without padding: output spatial = input - (kernel-1)."""
     model: torch.nn.Module = Conv2dNoPadModel().to(device)

crates/luminal_python/tests/test_models.py

@@ -1623,32 +1623,16 @@ class SplitTestModel(torch.nn.Module):
 
 
 class ArgsortStableDuplicatesModel(torch.nn.Module):
-    """Tests deterministic duplicate ordering for exported argsort.
-
-    ``idx_dtype`` parameterizes the integer dtype of the returned indices so
-    the test can verify dtype preservation across luminal's int dtype paths
-    (LUM-486). PyTorch's argsort always produces int64; the cast at the end
-    lets us drive the same model toward int32 or int64 outputs.
-    """
+    """Tests deterministic duplicate ordering for exported argsort."""
 
     SORT_DIM = 1
 
-    def __init__(self, idx_dtype: torch.dtype = torch.int64) -> None:
-        super().__init__()
-        self.idx_dtype = idx_dtype
-
     def forward(self, x: torch.Tensor) -> torch.Tensor:
-        return torch.argsort(x, dim=self.SORT_DIM).to(self.idx_dtype)
+        return torch.argsort(x, dim=self.SORT_DIM)
 
 
 class TinyMoERoutingModel(torch.nn.Module):
-    """Minimal deterministic MoE-style routing proof for PT2/native and CUDA.
-
-    ``idx_dtype`` casts the integer-valued outputs (routed_indices, dispatch,
-    group_ids) to the requested dtype so the test can sweep int32 and int64
-    output paths (LUM-486). Internal indices stay int64 because torch.gather
-    / torch.scatter require int64 index tensors.
-    """
+    """Minimal deterministic MoE-style routing proof for PT2/native and CUDA."""
 
     TOP_K = 2
     ROUTING_DIM = -1
@@ -1656,9 +1640,8 @@ class TinyMoERoutingModel(torch.nn.Module):
     DISPATCH_ON = 1
     GROUP_SIZE = 2
 
-    def __init__(self, idx_dtype: torch.dtype = torch.int64) -> None:
+    def __init__(self) -> None:
         super().__init__()
-        self.idx_dtype = idx_dtype
         self.register_buffer(
             "expert_scale",
             torch.tensor([1.5, -0.5, 2.0, 0.25], dtype=torch.float32),
@@ -1694,11 +1677,11 @@ class TinyMoERoutingModel(torch.nn.Module):
         group_ids = torch.floor_divide(routed_indices, self.GROUP_SIZE)
         routing_sign = torch.sign(masked_values)
         return (
-            routed_indices.to(self.idx_dtype),
+            routed_indices,
             masked_values,
-            dispatch.to(self.idx_dtype),
+            dispatch,
             inactive_mask,
-            group_ids.to(self.idx_dtype),
+            group_ids,
             routing_sign,
         )
 
@@ -1969,24 +1952,6 @@ class Conv1dBiasModel(torch.nn.Module):
         return self.conv(x)
 
 
-class Conv1dFloorDivPositionalModel(torch.nn.Module):
-    """Whisper-like Conv1d downsample followed by a fixed positional add."""
-
-    def __init__(self) -> None:
-        super().__init__()
-        self.conv1 = torch.nn.Conv1d(8, 16, kernel_size=3, padding=1, bias=True)
-        self.conv2 = torch.nn.Conv1d(
-            16, 16, kernel_size=3, stride=2, padding=1, bias=True
-        )
-        self.position = torch.nn.Parameter(torch.randn(15, 16))
-
-    def forward(self, x: torch.Tensor) -> torch.Tensor:
-        x = torch.nn.functional.gelu(self.conv1(x))
-        x = torch.nn.functional.gelu(self.conv2(x))
-        x = x.squeeze(0).transpose(0, 1)
-        return x + self.position
-
-
 class Conv2dNoPadModel(torch.nn.Module):
     """Conv2d with no padding: output spatial dims shrink by (kernel-1)."""
 

examples/gemma/src/model.rs

@@ -315,13 +315,8 @@ fn hlir_attention(
     let v_cache_out = v_new.scatter(scatter_idx, v_cache_in);
 
     // Slice to valid range
-    let mut k_full = k_cache_out.slice((.., ..total_seq, ..));
-    let mut v_full = v_cache_out.slice((.., ..total_seq, ..));
-    // LUM-545: model invariant `prev + seq <= max_seq`, but the frontend
-    // cannot yet propagate expression-bound assertions, so `slice` reports
-    // `min(max_seq, p+s)`. Normalize the visible cache axis to `total_seq`.
-    k_full.shape.dims[1] = total_seq;
-    v_full.shape.dims[1] = total_seq;
+    let k_full = k_cache_out.slice((.., ..total_seq, ..));
+    let v_full = v_cache_out.slice((.., ..total_seq, ..));
 
     // GQA expand: [N_KV_HEADS, total_seq, HEAD_DIM] -> [N_HEADS, total_seq, HEAD_DIM]
     let k_3d = k_full.expand_dim(1, KV_GROUPS).merge_dims(0, 1);

examples/gemma4_moe/src/main.rs

@@ -1,5 +1,3 @@
-#[path = "../../../examples_common/benchmark_stdio.rs"]
-mod benchmark_stdio;
 mod hf;
 mod model;
 
@@ -8,14 +6,18 @@ use luminal::prelude::*;
 use luminal_cuda_lite::{cudarc::driver::CudaContext, runtime::CudaRuntime};
 use model::*;
 use rustc_hash::FxHashSet;
-use std::{
-    io::Write,
-    time::{Duration, Instant},
-};
+use std::{io::Write, time::Duration};
 use tokenizers::Tokenizer;
 
 const REPO_ID: &str = "google/gemma-4-26B-A4B";
 
+fn env_usize(name: &str, default: usize) -> usize {
+    std::env::var(name)
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(default)
+}
+
 fn env_bool(name: &str) -> bool {
     std::env::var(name)
         .ok()
@@ -23,10 +25,9 @@ fn env_bool(name: &str) -> bool {
 }
 
 fn main() {
-    let stdio = benchmark_stdio::enabled();
-    let max_seq_len = benchmark_stdio::env_usize("MAX_SEQ_LEN", 4096);
-    let gen_tokens = benchmark_stdio::env_usize("GEN_TOKENS", 30);
-    let search_graphs = benchmark_stdio::env_usize("SEARCH_GRAPHS", 50);
+    let max_seq_len = env_usize("MAX_SEQ_LEN", 4096);
+    let gen_tokens = env_usize("GEN_TOKENS", 30);
+    let search_graphs = env_usize("SEARCH_GRAPHS", 50);
     let prompt = std::env::var("PROMPT").unwrap_or_else(|_| "The capital of France is".to_string());
     let print_token_ids = env_bool("PRINT_TOKEN_IDS");
 
@@ -37,6 +38,11 @@ fn main() {
     println!("Using model directory: {}", model_dir.display());
 
     let tokenizer = Tokenizer::from_file(model_dir.join("tokenizer.json")).unwrap();
+    let prompt_tokens = tokenizer
+        .encode(prompt.as_str(), true)
+        .unwrap()
+        .get_ids()
+        .to_vec();
 
     let mut cx = Graph::default();
     let input = cx.named_tensor("input", 's').as_dtype(DType::Int);
@@ -57,14 +63,11 @@ fn main() {
     let weights_path = model_dir.join("model_combined.safetensors");
     runtime.load_safetensors(&cx, weights_path.to_str().unwrap());
 
-    let reset_cache = |runtime: &mut CudaRuntime| {
-        for layer in 0..LAYERS {
-            let cache_bytes = cache_bytes_for_layer(layer, max_seq_len);
-            runtime.set_zeros(kv_cache.k_caches[layer], cache_bytes);
-            runtime.set_zeros(kv_cache.v_caches[layer], cache_bytes);
-        }
-    };
-    reset_cache(&mut runtime);
+    for layer in 0..LAYERS {
+        let cache_bytes = cache_bytes_for_layer(layer, max_seq_len);
+        runtime.set_zeros(kv_cache.k_caches[layer], cache_bytes);
+        runtime.set_zeros(kv_cache.v_caches[layer], cache_bytes);
+    }
 
     println!("Compiling...");
     cx.set_dim('s', 1);
@@ -72,66 +75,15 @@ fn main() {
     runtime.set_data(input, vec![1]);
     runtime.set_data(pos_ids, vec![1]);
     runtime = cx.search(runtime, search_graphs);
-    reset_cache(&mut runtime);
 
-    if stdio {
-        benchmark_stdio::serve(|prompt| {
-            reset_cache(&mut runtime);
-            run_prompt(
-                prompt,
-                gen_tokens,
-                print_token_ids,
-                &tokenizer,
-                &mut cx,
-                &mut runtime,
-                input,
-                pos_ids,
-                logits,
-                &cache_outputs,
-                &kv_cache,
-                true,
-            );
-        });
-    } else {
-        run_prompt(
-            &prompt,
-            gen_tokens,
-            print_token_ids,
-            &tokenizer,
-            &mut cx,
-            &mut runtime,
-            input,
-            pos_ids,
-            logits,
-            &cache_outputs,
-            &kv_cache,
-            false,
-        );
+    for layer in 0..LAYERS {
+        let cache_bytes = cache_bytes_for_layer(layer, max_seq_len);
+        runtime.set_zeros(kv_cache.k_caches[layer], cache_bytes);
+        runtime.set_zeros(kv_cache.v_caches[layer], cache_bytes);
     }
-}
 
-#[allow(clippy::too_many_arguments)]
-fn run_prompt(
-    prompt: &str,
-    gen_tokens: usize,
-    print_token_ids: bool,
-    tokenizer: &Tokenizer,
-    cx: &mut Graph,
-    runtime: &mut CudaRuntime,
-    input: GraphTensor,
-    pos_ids: GraphTensor,
-    logits: GraphTensor,
-    cache_outputs: &[(GraphTensor, GraphTensor)],
-    kv_cache: &KVCache,
-    stdio: bool,
-) {
-    let prompt_tokens = tokenizer.encode(prompt, true).unwrap().get_ids().to_vec();
-    let query_start = Instant::now();
-
-    if !stdio {
-        print!("{prompt}");
-        std::io::stdout().flush().unwrap();
-    }
+    print!("{prompt}");
+    std::io::stdout().flush().unwrap();
 
     let mut prev_seq = 0usize;
     let mut fwd_durations = vec![];
@@ -141,7 +93,7 @@ fn run_prompt(
 
     const EOS_TOKEN: u32 = 1;
 
-    let prefill_start = Instant::now();
+    let prefill_start = std::time::Instant::now();
     for &token in &prompt_tokens {
         cx.set_dim('s', 1);
         cx.set_dim('p', prev_seq);
@@ -169,26 +121,12 @@ fn run_prompt(
         .unwrap()
         .0 as u32;
     generated_token_ids.push(next_token);
-    let mut generated = 0usize;
-    if stdio {
-        if next_token != EOS_TOKEN {
-            let decoded = tokenizer.decode(&[next_token], true).unwrap();
-            benchmark_stdio::emit_token(&decoded);
-            generated += 1;
-        }
-    } else {
-        let decoded = tokenizer.decode(&[next_token], true).unwrap();
-        print!("{decoded}");
-        std::io::stdout().flush().unwrap();
-    }
+    print!("{}", tokenizer.decode(&[next_token], true).unwrap());
+    std::io::stdout().flush().unwrap();
     seen_tokens.insert(next_token);
 
     for _ in 1..gen_tokens {
-        if stdio && next_token == EOS_TOKEN {
-            break;
-        }
-
-        let start = Instant::now();
+        let start = std::time::Instant::now();
         cx.set_dim('s', 1);
         cx.set_dim('p', prev_seq);
         runtime.set_data(input, vec![next_token as i32]);
@@ -227,21 +165,10 @@ fn run_prompt(
             break;
         }
 
-        let decoded = tokenizer.decode(&[next_token], true).unwrap();
-        if stdio {
-            benchmark_stdio::emit_token(&decoded);
-        } else {
-            print!("{decoded}");
-            std::io::stdout().flush().unwrap();
-        }
-        generated += 1;
+        print!("{}", tokenizer.decode(&[next_token], true).unwrap());
+        std::io::stdout().flush().unwrap();
         fwd_durations.push(start.elapsed());
     }
-    if stdio {
-        benchmark_stdio::emit_eoq(generated, query_start);
-        return;
-    }
-
     println!();
     if print_token_ids {
         println!("Generated token ids: {generated_token_ids:?}");

examples/gemma4_moe/src/model.rs

@@ -462,13 +462,8 @@ fn hlir_attention(
     let k_cache_out = k_new.scatter(scatter_idx, k_cache_in);
     let v_cache_out = v_new.scatter(scatter_idx, v_cache_in);
 
-    let mut k_full = k_cache_out.slice((.., ..total_seq, ..));
-    let mut v_full = v_cache_out.slice((.., ..total_seq, ..));
-    // LUM-545: model invariant `prev + seq <= max_seq`, but the frontend
-    // cannot yet propagate expression-bound assertions, so `slice` reports
-    // `min(max_seq, p+s)`. Normalize the visible cache axis to `total_seq`.
-    k_full.shape.dims[1] = total_seq;
-    v_full.shape.dims[1] = total_seq;
+    let k_full = k_cache_out.slice((.., ..total_seq, ..));
+    let v_full = v_cache_out.slice((.., ..total_seq, ..));
 
     let k_3d = k_full.expand_dim(1, spec.kv_groups).merge_dims(0, 1);
     let v_3d = v_full.expand_dim(1, spec.kv_groups).merge_dims(0, 1);
@@ -621,8 +616,6 @@ impl Gemma4SparseMoE {
         let hidden_exp = hidden.unsqueeze(2);
         let down_out = hidden_exp.matmul(down_gathered.transpose(2, 3)).squeeze(2);
 
-        let mut weights_exp = top_k_weights.unsqueeze(top_k_weights.dims().len());
-        weights_exp.shape.expand(down_out.dims());
-        (down_out * weights_exp).sum(n - 1)
+        (down_out * top_k_weights.unsqueeze(top_k_weights.dims().len())).sum(n - 1)
     }
 }

examples/llama/src/main.rs

@@ -1,5 +1,3 @@
-#[path = "../../../examples_common/benchmark_stdio.rs"]
-mod benchmark_stdio;
 mod hf;
 mod model;
 
@@ -9,36 +7,22 @@ use luminal_cuda_lite::{cudarc::driver::CudaContext, runtime::CudaRuntime};
 use luminal_tracing::*;
 use model::*;
 use rustc_hash::FxHashSet;
-use std::{
-    io::Write,
-    time::{Duration, Instant},
-};
+use std::{io::Write, time::Duration};
 use tokenizers::Tokenizer;
 use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
 const REPO_ID: &str = "NousResearch/Meta-Llama-3-8B-Instruct";
 
 fn main() {
-    let stdio = benchmark_stdio::enabled();
     let max_seq_len = 4096;
-    let gen_tokens = if stdio {
-        benchmark_stdio::env_usize("GEN_TOKENS", 500)
-    } else {
-        500
-    };
-    let search_graphs = if stdio {
-        benchmark_stdio::env_usize("SEARCH_GRAPHS", 500)
-    } else {
-        500
-    };
+    let gen_tokens = 500;
+    let search_graphs = 500;
     let prompt = "Explain what a neural network is in a paragraph.";
 
-    if !stdio {
-        tracing_subscriber::registry()
-            .with(tracing_subscriber::fmt::layer())
-            .with(luminal_filter())
-            .init();
-    }
+    tracing_subscriber::registry()
+        .with(tracing_subscriber::fmt::layer())
+        .with(luminal_filter())
+        .init();
 
     let ctx = CudaContext::new(0).unwrap();
     let stream = ctx.default_stream();
@@ -47,6 +31,14 @@ fn main() {
     println!("Using model directory: {}", model_dir.display());
 
     let tokenizer = Tokenizer::from_file(model_dir.join("tokenizer.json")).unwrap();
+    let chat_prompt = format!(
+        "<|start_header_id|>user<|end_header_id|>\n\n{prompt}<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n"
+    );
+    let prompt_tokens = tokenizer
+        .encode(chat_prompt.as_str(), true)
+        .unwrap()
+        .get_ids()
+        .to_vec();
 
     // Build graph
     let mut cx = Graph::default();
@@ -74,13 +66,10 @@ fn main() {
     runtime.load_safetensors(&cx, weights_path.to_str().unwrap());
 
     let cache_bytes = N_KV_HEADS * max_seq_len * HEAD_DIM * std::mem::size_of::<f32>();
-    let reset_cache = |runtime: &mut CudaRuntime| {
-        for i in 0..LAYERS {
-            runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
-            runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
-        }
-    };
-    reset_cache(&mut runtime);
+    for i in 0..LAYERS {
+        runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
+        runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
+    }
 
     println!("Compiling...");
     cx.set_dim('s', 1);
@@ -88,65 +77,12 @@ fn main() {
     runtime.set_data(input, vec![1]);
     runtime.set_data(token_ids, vec![1]);
     runtime = cx.search(runtime, search_graphs);
-    reset_cache(&mut runtime);
 
-    if stdio {
-        benchmark_stdio::serve(|prompt| {
-            reset_cache(&mut runtime);
-            run_prompt(
-                prompt,
-                gen_tokens,
-                &tokenizer,
-                &mut cx,
-                &mut runtime,
-                input,
-                token_ids,
-                logits,
-                &cache_outputs,
-                &kv_cache,
-                true,
-            );
-        });
-    } else {
-        run_prompt(
-            prompt,
-            gen_tokens,
-            &tokenizer,
-            &mut cx,
-            &mut runtime,
-            input,
-            token_ids,
-            logits,
-            &cache_outputs,
-            &kv_cache,
-            false,
-        );
+    for i in 0..LAYERS {
+        runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
+        runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
     }
-}
 
-#[allow(clippy::too_many_arguments)]
-fn run_prompt(
-    prompt: &str,
-    gen_tokens: usize,
-    tokenizer: &Tokenizer,
-    cx: &mut Graph,
-    runtime: &mut CudaRuntime,
-    input: GraphTensor,
-    token_ids: GraphTensor,
-    logits: GraphTensor,
-    cache_outputs: &[(GraphTensor, GraphTensor)],
-    kv_cache: &KVCache,
-    stdio: bool,
-) {
-    let chat_prompt = format!(
-        "<|start_header_id|>user<|end_header_id|>\n\n{prompt}<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n"
-    );
-    let prompt_tokens = tokenizer
-        .encode(chat_prompt.as_str(), true)
-        .unwrap()
-        .get_ids()
-        .to_vec();
-    let query_start = Instant::now();
     let mut prev_seq = 1usize;
     let mut sentence = vec![prompt_tokens[0]];
     let total_steps = prompt_tokens.len() - 1 + gen_tokens;
@@ -158,16 +94,13 @@ fn run_prompt(
     const EOS_TOKEN: u32 = 128009;
     const STOP_TOKEN: u32 = 128001;
 
-    if !stdio {
-        println!(
-            "Prompt: {} tokens, generating up to {} tokens",
-            prompt_len, gen_tokens
-        );
-    }
+    println!(
+        "Prompt: {} tokens, generating up to {} tokens",
+        prompt_len, gen_tokens
+    );
 
-    let mut generated = 0usize;
     for i in 0..total_steps {
-        let start = Instant::now();
+        let start = std::time::Instant::now();
         let is_prefill = i < prompt_len - 1;
         let seq_len = sentence.len();
 
@@ -226,21 +159,12 @@ fn run_prompt(
         }
 
         let decoded = tokenizer.decode(&[next_token], true).unwrap();
-        if stdio {
-            benchmark_stdio::emit_token(&decoded);
-        } else {
-            print!("{}", decoded);
-            std::io::stdout().flush().unwrap();
-        }
-        generated += 1;
-    }
-    if stdio {
-        benchmark_stdio::emit_eoq(generated, query_start);
-        return;
+        print!("{}", decoded);
+        std::io::stdout().flush().unwrap();
     }
+    println!();
 
     // Benchmarks
-    println!();
     let decode_durations: Vec<_> = fwd_durations.iter().skip(prompt_len).collect();
     if decode_durations.len() > 2 {
         println!(

examples/llama/src/model.rs

@@ -246,13 +246,8 @@ fn hlir_attention(
     let v_cache_out = v_new.scatter(scatter_idx, v_cache_in);
 
     // Slice to valid range: [N_KV_HEADS, total_seq, HEAD_DIM]
-    let mut k_full = k_cache_out.slice((.., ..total_seq, ..));
-    let mut v_full = v_cache_out.slice((.., ..total_seq, ..));
-    // LUM-545: model invariant `prev + seq <= max_seq`, but the frontend
-    // cannot yet propagate expression-bound assertions, so `slice` reports
-    // `min(max_seq, p+s)`. Normalize the visible cache axis to `total_seq`.
-    k_full.shape.dims[1] = total_seq;
-    v_full.shape.dims[1] = total_seq;
+    let k_full = k_cache_out.slice((.., ..total_seq, ..));
+    let v_full = v_cache_out.slice((.., ..total_seq, ..));
 
     // GQA expand: [N_KV_HEADS, total_seq, HEAD_DIM] -> [N_HEADS, total_seq, HEAD_DIM]
     let k_3d = k_full.expand_dim(1, KV_GROUPS).merge_dims(0, 1);

examples/qwen/src/main.rs

@@ -1,5 +1,3 @@
-#[path = "../../../examples_common/benchmark_stdio.rs"]
-mod benchmark_stdio;
 mod hf;
 mod model;
 
@@ -9,36 +7,22 @@ use luminal_cuda_lite::{cudarc::driver::CudaContext, runtime::CudaRuntime};
 use luminal_tracing::*;
 use model::*;
 use rustc_hash::FxHashSet;
-use std::{
-    io::Write,
-    time::{Duration, Instant},
-};
+use std::{io::Write, time::Duration};
 use tokenizers::Tokenizer;
 use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
 const REPO_ID: &str = "Qwen/Qwen3-4B";
 
 fn main() {
-    let stdio = benchmark_stdio::enabled();
     let max_seq_len = 4096;
-    let gen_tokens = if stdio {
-        benchmark_stdio::env_usize("GEN_TOKENS", 500)
-    } else {
-        500
-    };
-    let search_graphs = if stdio {
-        benchmark_stdio::env_usize("SEARCH_GRAPHS", 500)
-    } else {
-        500
-    };
+    let gen_tokens = 500;
+    let search_graphs = 500;
     let prompt = "Explain what a neural network is in a paragraph.";
 
-    if !stdio {
-        tracing_subscriber::registry()
-            .with(tracing_subscriber::fmt::layer())
-            .with(luminal_filter())
-            .init();
-    }
+    tracing_subscriber::registry()
+        .with(tracing_subscriber::fmt::layer())
+        .with(luminal_filter())
+        .init();
 
     let ctx = CudaContext::new(0).unwrap();
     let stream = ctx.default_stream();
@@ -47,6 +31,7 @@ fn main() {
     println!("Using model directory: {}", model_dir.display());
 
     let tokenizer = Tokenizer::from_file(model_dir.join("tokenizer.json")).unwrap();
+    let prompt_tokens = tokenizer.encode(prompt, true).unwrap().get_ids().to_vec();
 
     // Build graph
     let mut cx = Graph::default();
@@ -69,13 +54,10 @@ fn main() {
     runtime.load_safetensors(&cx, weights_path.to_str().unwrap());
 
     let cache_bytes = N_KV_HEADS * max_seq_len * HEAD_DIM * std::mem::size_of::<f32>();
-    let reset_cache = |runtime: &mut CudaRuntime| {
-        for i in 0..LAYERS {
-            runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
-            runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
-        }
-    };
-    reset_cache(&mut runtime);
+    for i in 0..LAYERS {
+        runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
+        runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
+    }
 
     println!("Compiling...");
     cx.set_dim('s', 1);
@@ -83,58 +65,12 @@ fn main() {
     runtime.set_data(input, vec![1]);
     runtime.set_data(token_ids, vec![1]);
     runtime = cx.search(runtime, search_graphs);
-    reset_cache(&mut runtime);
 
-    if stdio {
-        benchmark_stdio::serve(|prompt| {
-            reset_cache(&mut runtime);
-            run_prompt(
-                prompt,
-                gen_tokens,
-                &tokenizer,
-                &mut cx,
-                &mut runtime,
-                input,
-                token_ids,
-                logits,
-                &cache_outputs,
-                &kv_cache,
-                true,
-            );
-        });
-    } else {
-        run_prompt(
-            prompt,
-            gen_tokens,
-            &tokenizer,
-            &mut cx,
-            &mut runtime,
-            input,
-            token_ids,
-            logits,
-            &cache_outputs,
-            &kv_cache,
-            false,
-        );
+    for i in 0..LAYERS {
+        runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
+        runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
     }
-}
 
-#[allow(clippy::too_many_arguments)]
-fn run_prompt(
-    prompt: &str,
-    gen_tokens: usize,
-    tokenizer: &Tokenizer,
-    cx: &mut Graph,
-    runtime: &mut CudaRuntime,
-    input: GraphTensor,
-    token_ids: GraphTensor,
-    logits: GraphTensor,
-    cache_outputs: &[(GraphTensor, GraphTensor)],
-    kv_cache: &KVCache,
-    stdio: bool,
-) {
-    let prompt_tokens = tokenizer.encode(prompt, true).unwrap().get_ids().to_vec();
-    let query_start = Instant::now();
     let mut prev_seq = 1usize;
     let mut sentence = vec![prompt_tokens[0]];
     let total_steps = prompt_tokens.len() - 1 + gen_tokens;
@@ -146,16 +82,13 @@ fn run_prompt(
     const EOS_TOKEN: u32 = 151645; // <|endoftext|>
     const STOP_TOKEN: u32 = 151643; // <|end|>
 
-    if !stdio {
-        println!(
-            "Prompt: {} tokens, generating up to {} tokens",
-            prompt_len, gen_tokens
-        );
-    }
+    println!(
+        "Prompt: {} tokens, generating up to {} tokens",
+        prompt_len, gen_tokens
+    );
 
-    let mut generated = 0usize;
     for i in 0..total_steps {
-        let start = Instant::now();
+        let start = std::time::Instant::now();
         let is_prefill = i < prompt_len - 1;
         let seq_len = sentence.len();
 
@@ -214,21 +147,12 @@ fn run_prompt(
         }
 
         let decoded = tokenizer.decode(&[next_token], true).unwrap();
-        if stdio {
-            benchmark_stdio::emit_token(&decoded);
-        } else {
-            print!("{}", decoded);
-            std::io::stdout().flush().unwrap();
-        }
-        generated += 1;
-    }
-    if stdio {
-        benchmark_stdio::emit_eoq(generated, query_start);
-        return;
+        print!("{}", decoded);
+        std::io::stdout().flush().unwrap();
     }
+    println!();
 
     // Benchmarks
-    println!();
     let decode_durations: Vec<_> = fwd_durations.iter().skip(prompt_len).collect();
     if decode_durations.len() > 2 {
         println!(

examples/qwen/src/model.rs

@@ -287,13 +287,8 @@ fn hlir_attention(
     let v_cache_out = v_new.scatter(scatter_idx, v_cache_in);
 
     // Slice to valid range: [N_KV_HEADS, total_seq, HEAD_DIM]
-    let mut k_full = k_cache_out.slice((.., ..total_seq, ..));
-    let mut v_full = v_cache_out.slice((.., ..total_seq, ..));
-    // LUM-545: model invariant `prev + seq <= max_seq`, but the frontend
-    // cannot yet propagate expression-bound assertions, so `slice` reports
-    // `min(max_seq, p+s)`. Normalize the visible cache axis to `total_seq`.
-    k_full.shape.dims[1] = total_seq;
-    v_full.shape.dims[1] = total_seq;
+    let k_full = k_cache_out.slice((.., ..total_seq, ..));
+    let v_full = v_cache_out.slice((.., ..total_seq, ..));
 
     // GQA expand: [N_KV_HEADS, total_seq, HEAD_DIM] -> [N_HEADS, total_seq, HEAD_DIM]
     let k_3d = k_full.expand_dim(1, KV_GROUPS).merge_dims(0, 1);

examples/qwen3_moe/src/main.rs

@@ -1,5 +1,3 @@
-#[path = "../../../examples_common/benchmark_stdio.rs"]
-mod benchmark_stdio;
 mod hf;
 mod model;
 
@@ -8,27 +6,15 @@ use luminal::prelude::*;
 use luminal_cuda_lite::{cudarc::driver::CudaContext, runtime::CudaRuntime};
 use model::*;
 use rustc_hash::FxHashSet;
-use std::{
-    io::Write,
-    time::{Duration, Instant},
-};
+use std::{io::Write, time::Duration};
 use tokenizers::Tokenizer;
 
 const REPO_ID: &str = "Qwen/Qwen3-30B-A3B";
 
 fn main() {
-    let stdio = benchmark_stdio::enabled();
     let max_seq_len = 4096;
-    let gen_tokens = if stdio {
-        benchmark_stdio::env_usize("GEN_TOKENS", 30)
-    } else {
-        30
-    };
-    let search_graphs = if stdio {
-        benchmark_stdio::env_usize("SEARCH_GRAPHS", 50)
-    } else {
-        50
-    };
+    let gen_tokens = 30;
+    let search_graphs = 50;
     let prompt = "The capital of France is";
 
     let ctx = CudaContext::new(0).unwrap();
@@ -38,6 +24,7 @@ fn main() {
     println!("Using model directory: {}", model_dir.display());
 
     let tokenizer = Tokenizer::from_file(model_dir.join("tokenizer.json")).unwrap();
+    let prompt_tokens = tokenizer.encode(prompt, true).unwrap().get_ids().to_vec();
 
     // Build graph
     let mut cx = Graph::default();
@@ -60,13 +47,10 @@ fn main() {
     runtime.load_safetensors(&cx, weights_path.to_str().unwrap());
 
     let cache_bytes = N_KV_HEADS * max_seq_len * HEAD_DIM * std::mem::size_of::<f32>();
-    let reset_cache = |runtime: &mut CudaRuntime| {
-        for i in 0..LAYERS {
-            runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
-            runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
-        }
-    };
-    reset_cache(&mut runtime);
+    for i in 0..LAYERS {
+        runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
+        runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
+    }
 
     println!("Compiling...");
     cx.set_dim('s', 1);
@@ -74,63 +58,14 @@ fn main() {
     runtime.set_data(input, vec![1]);
     runtime.set_data(pos_ids, vec![1]);
     runtime = cx.search(runtime, search_graphs);
-    reset_cache(&mut runtime);
 
-    if stdio {
-        benchmark_stdio::serve(|prompt| {
-            reset_cache(&mut runtime);
-            run_prompt(
-                prompt,
-                gen_tokens,
-                &tokenizer,
-                &mut cx,
-                &mut runtime,
-                input,
-                pos_ids,
-                logits,
-                &cache_outputs,
-                &kv_cache,
-                true,
-            );
-        });
-    } else {
-        run_prompt(
-            prompt,
-            gen_tokens,
-            &tokenizer,
-            &mut cx,
-            &mut runtime,
-            input,
-            pos_ids,
-            logits,
-            &cache_outputs,
-            &kv_cache,
-            false,
-        );
+    for i in 0..LAYERS {
+        runtime.set_zeros(kv_cache.k_caches[i], cache_bytes);
+        runtime.set_zeros(kv_cache.v_caches[i], cache_bytes);
     }
-}
 
-#[allow(clippy::too_many_arguments)]
-fn run_prompt(
-    prompt: &str,
-    gen_tokens: usize,
-    tokenizer: &Tokenizer,
-    cx: &mut Graph,
-    runtime: &mut CudaRuntime,
-    input: GraphTensor,
-    pos_ids: GraphTensor,
-    logits: GraphTensor,
-    cache_outputs: &[(GraphTensor, GraphTensor)],
-    kv_cache: &KVCache,
-    stdio: bool,
-) {
-    let prompt_tokens = tokenizer.encode(prompt, true).unwrap().get_ids().to_vec();
-    let query_start = Instant::now();
-
-    if !stdio {
-        print!("{prompt}");
-        std::io::stdout().flush().unwrap();
-    }
+    print!("{prompt}");
+    std::io::stdout().flush().unwrap();
 
     let mut prev_seq = 0usize;
     let mut fwd_durations = vec![];
@@ -141,7 +76,7 @@ fn run_prompt(
     const STOP_TOKEN: u32 = 151643;
 
     // Prefill: process prompt tokens one at a time
-    let prefill_start = Instant::now();
+    let prefill_start = std::time::Instant::now();
     for &token in &prompt_tokens {
         cx.set_dim('s', 1);
         cx.set_dim('p', prev_seq);
@@ -170,27 +105,13 @@ fn run_prompt(
         .max_by(|(_, a), (_, b)| a.total_cmp(b))
         .unwrap()
         .0 as u32;
-    let mut generated = 0usize;
-    if stdio {
-        if next_token != EOS_TOKEN && next_token != STOP_TOKEN {
-            let decoded = tokenizer.decode(&[next_token], true).unwrap();
-            benchmark_stdio::emit_token(&decoded);
-            generated += 1;
-        }
-    } else {
-        let decoded = tokenizer.decode(&[next_token], true).unwrap();
-        print!("{decoded}");
-        std::io::stdout().flush().unwrap();
-    }
+    print!("{}", tokenizer.decode(&[next_token], true).unwrap());
+    std::io::stdout().flush().unwrap();
     seen_tokens.insert(next_token);
 
     // Decode loop
     for _ in 1..gen_tokens {
-        if stdio && (next_token == EOS_TOKEN || next_token == STOP_TOKEN) {
-            break;
-        }
-
-        let start = Instant::now();
+        let start = std::time::Instant::now();
         cx.set_dim('s', 1);
         cx.set_dim('p', prev_seq);
         runtime.set_data(input, vec![next_token as i32]);
@@ -229,23 +150,13 @@ fn run_prompt(
             break;
         }
 
-        let decoded = tokenizer.decode(&[next_token], true).unwrap();
-        if stdio {
-            benchmark_stdio::emit_token(&decoded);
-        } else {
-            print!("{decoded}");
-            std::io::stdout().flush().unwrap();
-        }
-        generated += 1;
+        print!("{}", tokenizer.decode(&[next_token], true).unwrap());
+        std::io::stdout().flush().unwrap();
         fwd_durations.push(start.elapsed());
     }
-    if stdio {
-        benchmark_stdio::emit_eoq(generated, query_start);
-        return;
-    }
+    println!();
 
     // Report benchmarks
-    println!();
     println!(
         "  TTFT: {:.2} ms ({} prompt tokens)",
         prefill_duration.as_secs_f64() * 1e3,

examples/qwen3_moe/src/model.rs

@@ -287,8 +287,7 @@ impl QwenMoE {
         let down_out = hidden_exp.matmul(down_gathered.transpose(2, 3)).squeeze(2); // [s, k, H]
 
         // 7. Weighted sum over k experts → [s, H]
-        let mut weights_exp = top_k_values.unsqueeze(top_k_values.dims().len()); // [s, k, 1]
-        weights_exp.shape.expand(down_out.dims());
+        let weights_exp = top_k_values.unsqueeze(top_k_values.dims().len()); // [s, k, 1]
         (down_out * weights_exp).sum(n - 1)
     }
 }
@@ -386,13 +385,8 @@ fn attention(
     let k_cache_out = k_new.scatter(scatter_idx, k_cache_in);
     let v_cache_out = v_new.scatter(scatter_idx, v_cache_in);
 
-    let mut k_full = k_cache_out.slice((.., ..total_seq, ..));
-    let mut v_full = v_cache_out.slice((.., ..total_seq, ..));
-    // LUM-545: model invariant `prev + seq <= max_seq`, but the frontend
-    // cannot yet propagate expression-bound assertions, so `slice` reports
-    // `min(max_seq, p+s)`. Normalize the visible cache axis to `total_seq`.
-    k_full.shape.dims[1] = total_seq;
-    v_full.shape.dims[1] = total_seq;
+    let k_full = k_cache_out.slice((.., ..total_seq, ..));
+    let v_full = v_cache_out.slice((.., ..total_seq, ..));
 
     // GQA expand
     let k_3d = k_full.expand_dim(1, KV_GROUPS).merge_dims(0, 1);

examples/whisper/src/model.rs

@@ -174,13 +174,8 @@ fn decoder_self_attention(
     let k_cache_out = k_new.scatter(scatter_idx, k_cache_in);
     let v_cache_out = v_new.scatter(scatter_idx, v_cache_in);
 
-    let mut k_full = k_cache_out.slice((.., ..total, ..));
-    let mut v_full = v_cache_out.slice((.., ..total, ..));
-    // LUM-545: model invariant `prev + seq <= max_seq`, but the frontend
-    // cannot yet propagate expression-bound assertions, so `slice` reports
-    // `min(max_seq, p+s)`. Normalize the visible cache axis to `total`.
-    k_full.shape.dims[1] = total;
-    v_full.shape.dims[1] = total;
+    let k_full = k_cache_out.slice((.., ..total, ..));
+    let v_full = v_cache_out.slice((.., ..total, ..));
 
     let q = split_heads(q);
 

examples_common/benchmark_stdio.rs

@@ -1,58 +0,0 @@
-use std::{
-    io::{BufRead, Write},
-    time::Instant,
-};
-
-pub fn enabled() -> bool {
-    std::env::args().any(|arg| arg == "--stdio")
-}
-
-pub fn env_usize(name: &str, default: usize) -> usize {
-    std::env::var(name)
-        .ok()
-        .and_then(|s| s.parse().ok())
-        .unwrap_or(default)
-}
-
-fn emit_ready() {
-    println!("READY");
-    std::io::stdout().flush().unwrap();
-}
-
-pub fn serve(mut f: impl FnMut(&str)) {
-    emit_ready();
-
-    let stdin = std::io::stdin();
-    for line in stdin.lock().lines() {
-        let line = line.unwrap();
-        f(&line);
-    }
-}
-
-pub fn emit_token(token: &str) {
-    println!("TOK\t{}", escape_token(token));
-    std::io::stdout().flush().unwrap();
-}
-
-pub fn emit_eoq(generated: usize, query_start: Instant) {
-    println!(
-        "EOQ\t{}\t{:.3}",
-        generated,
-        query_start.elapsed().as_secs_f64() * 1e3
-    );
-    std::io::stdout().flush().unwrap();
-}
-
-fn escape_token(s: &str) -> String {
-    let mut out = String::with_capacity(s.len());
-    for ch in s.chars() {
-        match ch {
-            '\\' => out.push_str("\\\\"),
-            '\t' => out.push_str("\\t"),
-            '\n' => out.push_str("\\n"),
-            '\r' => out.push_str("\\r"),
-            _ => out.push(ch),
-        }
-    }
-    out
-}

src/dyn_backend.rs

@@ -7,13 +7,14 @@
 //! - [`NativeDynBackend`]: the reference implementation for CPU
 
 use std::collections::HashMap;
+use std::time::Duration;
 
 use half::{bf16, f16};
 use petgraph::stable_graph::NodeIndex;
 use rustc_hash::FxHashMap;
 
 use crate::dtype::DType;
-use crate::graph::Graph;
+use crate::graph::{Graph, SearchOptions};
 use crate::hlir::{NativeData, NativeRuntime, Output};
 use crate::op::Runtime;
 
@@ -46,6 +47,18 @@ pub trait DynBackend {
     }
     fn execute(&mut self, dyn_map: &FxHashMap<char, usize>);
 
+    // --- Optional diagnostics --------------------------------------------
+
+    fn kernel_names(&self) -> Vec<String> {
+        vec![]
+    }
+
+    fn host_op_names(&self) -> Vec<String> {
+        vec![]
+    }
+
+    fn print_execution_stats(&self) {}
+
     // --- Optional device pointer support (GPU backends) --------------------
 
     fn supports_device_ptrs(&self) -> bool {
@@ -162,7 +175,9 @@ pub fn compile_backend<Rt: Runtime + 'static>(
     }
 
     // Search
-    let mut rt = graph.search(rt, args.search_iters);
+    let mut rng = rand::rng();
+    let search_options = search_options_from_env(args.search_iters);
+    let mut rt = graph.search_options(rt, search_options, &mut rng);
 
     // Rebuild label map after search (graph may have changed)
     let label_map = build_label_map(graph);
@@ -179,6 +194,39 @@ pub fn compile_backend<Rt: Runtime + 'static>(
     Ok(wrap(rt))
 }
 
+fn env_usize(name: &str) -> Option<usize> {
+    std::env::var(name).ok()?.parse().ok()
+}
+
+fn env_duration_ms(name: &str) -> Option<Duration> {
+    Some(Duration::from_millis(env_usize(name)? as u64))
+}
+
+fn search_options_from_env(limit: usize) -> SearchOptions {
+    let mut options = SearchOptions::new(limit);
+
+    if let Some(generation_size) = env_usize("LUMINAL_SEARCH_GENERATION_SIZE") {
+        options = options.generation_size(generation_size);
+    }
+    if let Some(mutations) = env_usize("LUMINAL_SEARCH_MUTATIONS") {
+        options = options.mutations(mutations);
+    }
+    if let Some(trials) = env_usize("LUMINAL_SEARCH_TRIALS") {
+        options = options.trials(trials);
+    }
+    if let Some(keep_best) = env_usize("LUMINAL_SEARCH_KEEP_BEST") {
+        options = options.keep_best(keep_best);
+    }
+    if let Some(profile_timeout) = env_duration_ms("LUMINAL_SEARCH_PROFILE_TIMEOUT_MS") {
+        options = options.profile_timeout(profile_timeout);
+    }
+    if let Some(group_timeout) = env_duration_ms("LUMINAL_SEARCH_GROUP_TIMEOUT_MS") {
+        options = options.group_timeout(group_timeout);
+    }
+
+    options
+}
+
 // ---------------------------------------------------------------------------
 // Shared utilities
 // ---------------------------------------------------------------------------

src/frontend/binary.rs

@@ -11,7 +11,6 @@ impl Add for GraphTensor {
     type Output = GraphTensor;
 
     fn add(self, rhs: GraphTensor) -> Self::Output {
-        assert_eq!(self.dims(), rhs.dims(), "Dims must match to add tensors.");
         assert_eq!(
             self.dtype, rhs.dtype,
             "Dtypes must match to add tensors. Got {:?} and {:?}",
@@ -74,11 +73,6 @@ impl Mul for GraphTensor {
     type Output = GraphTensor;
 
     fn mul(self, rhs: GraphTensor) -> Self::Output {
-        assert_eq!(
-            self.dims(),
-            rhs.dims(),
-            "Dims must match to multiply tensors."
-        );
         assert_eq!(
             self.dtype, rhs.dtype,
             "Dtypes must match to multiply tensors. Got {:?} and {:?}",
@@ -480,42 +474,6 @@ pub(super) mod tests {
         assert_close(rt.get_f32(c.id), &ref_c.to_vec1::<f32>().unwrap())
     }
 
-    #[test]
-    #[should_panic(expected = "Dims must match to add tensors.")]
-    fn test_add_rejects_implicit_broadcast() {
-        let mut cx = Graph::new();
-        let a = cx.tensor((2, 3));
-        let b = cx.tensor((1, 3));
-        let _ = a + b;
-    }
-
-    #[test]
-    #[should_panic(expected = "Dims must match to multiply tensors.")]
-    fn test_mul_rejects_implicit_broadcast() {
-        let mut cx = Graph::new();
-        let a = cx.tensor((2, 3));
-        let b = cx.tensor((1, 3));
-        let _ = a * b;
-    }
-
-    #[test]
-    #[should_panic(expected = "Dims must match to mod tensors.")]
-    fn test_mod_rejects_implicit_broadcast() {
-        let mut cx = Graph::new();
-        let a = cx.tensor((2, 3));
-        let b = cx.tensor((1, 3));
-        let _ = a % b;
-    }
-
-    #[test]
-    #[should_panic(expected = "Dims must match to lt tensors.")]
-    fn test_lt_rejects_implicit_broadcast() {
-        let mut cx = Graph::new();
-        let a = cx.tensor((2, 3));
-        let b = cx.tensor((1, 3));
-        let _ = a.lt(b);
-    }
-
     proptest! {
         #![proptest_config(ProptestConfig::with_cases(10))]
         #[test]
@@ -599,27 +557,6 @@ pub(super) mod tests {
         }
     }
 
-    proptest! {
-        #![proptest_config(ProptestConfig::with_cases(10))]
-        #[test]
-        fn test_mod_scalar_broadcast(size in 1usize..64) {
-            // rank-0 RHS expanded against rank-N LHS, mirroring `x % torch.tensor(c)`.
-            test_binary_transforms(
-                size,
-                (),
-                |a, b| a % b.expand_rhs(a.shape),
-                |a, b| {
-                    let lhs = a.to_vec1::<f32>().unwrap();
-                    let rhs_scalar = b.to_scalar::<f32>().unwrap();
-                    let remainder: Vec<f32> = lhs.iter().map(|x| x % rhs_scalar).collect();
-                    Tensor::from_vec(remainder, size, &Device::Cpu).unwrap()
-                },
-                identity,
-                shift_from_zero,
-            );
-        }
-    }
-
     proptest! {
         #![proptest_config(ProptestConfig::with_cases(10))]
         #[test]
@@ -633,28 +570,6 @@ pub(super) mod tests {
         }
     }
 
-    proptest! {
-        #![proptest_config(ProptestConfig::with_cases(10))]
-        #[test]
-        fn test_lt_scalar_broadcast(size in 1usize..64) {
-            // rank-0 RHS expanded against rank-N LHS for `lt`.
-            test_binary(
-                size,
-                (),
-                |a, b| a.lt(b.expand_rhs(a.shape)).cast(crate::dtype::DType::F32),
-                |a, b| {
-                    let scalar = b.to_scalar::<f32>().unwrap();
-                    let lhs = a.to_vec1::<f32>().unwrap();
-                    let result: Vec<f32> = lhs
-                        .iter()
-                        .map(|x| if *x < scalar { 1.0f32 } else { 0.0f32 })
-                        .collect();
-                    Tensor::from_vec(result, size, &Device::Cpu).unwrap()
-                },
-            );
-        }
-    }
-
     proptest! {
         #![proptest_config(ProptestConfig::with_cases(10))]
         #[test]

src/frontend/movement.rs

@@ -467,7 +467,7 @@ impl GraphTensor {
         let mut win = Vec::with_capacity(n);
         for (((dim, k), s), d) in dims.iter().zip(&kernel).zip(&strides).zip(&dilation) {
             let effective_window = *d * (*k - 1) + 1;
-            win.push((*dim - effective_window).floor_div(s) + 1);
+            win.push(((*dim - effective_window) / s) + 1);
         }
 
         // [win..., kernel...]
@@ -905,14 +905,6 @@ mod tests {
         );
     }
 
-    #[test]
-    fn test_unfold_floor_div_shape_for_odd_window_numerator() {
-        let mut cx = Graph::new();
-        let inp = cx.tensor((80, 3000));
-        let out = inp.pad(((0, 0), (1, 1)), 0.).unfold((1, 3), (1, 2), (1, 1));
-        assert_eq!(out.dims(), &[80, 1500, 1, 3]);
-    }
-
     #[test]
     fn test_unsqueeze() {
         let mut cx = Graph::new();

src/hlir.rs

@@ -217,32 +217,38 @@ pub fn reduce_sort(name: &str) -> SortDef {
 }
 
 pub type HLIROps = (
-    Input,
-    Output,
-    CustomOpKind,
-    LoopStart,
-    LoopEnd,
-    LoopInput,
-    LoopInputStatic,
-    LoopOutput,
-    LoopOutputSelect,
-    Constant,
-    Cast,
-    Iota,
-    Exp2,
-    Log2,
-    Sin,
-    Recip,
-    Sqrt,
-    Add,
-    Mul,
-    Mod,
-    LessThan,
-    Gather,
-    Scatter,
-    SumReduce,
-    MaxReduce,
-    Softmax,
+    (
+        Input,
+        Output,
+        CustomOpKind,
+        LoopStart,
+        LoopEnd,
+        LoopInput,
+        LoopInputStatic,
+        LoopOutput,
+        LoopOutputSelect,
+        Constant,
+        Cast,
+        Iota,
+        Exp2,
+        Log2,
+    ),
+    (
+        Sin,
+        Recip,
+        Sqrt,
+        Add,
+        Mul,
+        Mod,
+        LessThan,
+        Gather,
+        Concat2D,
+        EmbeddingBagSum,
+        Scatter,
+        SumReduce,
+        MaxReduce,
+        Softmax,
+    ),
 );
 
 #[derive(Default, Debug, Clone)]
@@ -1721,7 +1727,9 @@ impl NativeOp for Add {
             NativeData::Int(a) => {
                 NativeData::Int(bin_fn(a_ind, a, b_ind, b, NativeData::i32, |x, y| x + y))
             }
-            NativeData::Bool(_) => panic!("Cannot add Bool tensors, cast to F32 first"),
+            NativeData::Bool(a) => {
+                NativeData::Bool(bin_fn(a_ind, a, b_ind, b, NativeData::bool, |x, y| x || y))
+            }
         }
     }
 }
@@ -1808,7 +1816,9 @@ impl NativeOp for Mul {
             NativeData::Int(a) => {
                 NativeData::Int(bin_fn(a_ind, a, b_ind, b, NativeData::i32, |x, y| x * y))
             }
-            NativeData::Bool(_) => panic!("Cannot multiply Bool tensors, cast to F32 first"),
+            NativeData::Bool(a) => {
+                NativeData::Bool(bin_fn(a_ind, a, b_ind, b, NativeData::bool, |x, y| x && y))
+            }
         }
     }
 }
@@ -2126,6 +2136,233 @@ impl NativeOp for Gather {
     }
 }
 
+#[derive(Debug, Clone, Default, PartialEq)]
+pub struct Concat2D {
+    pub rows: Expression,
+    pub lhs_cols: Expression,
+    pub rhs_cols: Expression,
+}
+impl Display for Concat2D {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Concat2D")
+    }
+}
+impl HLIROp for Concat2D {
+    fn to_egglog(&self, inputs: &[(NodeIndex, String)]) -> String {
+        format!(
+            "(Op (Concat2D {} {} {}) {})",
+            self.rows.to_egglog(),
+            self.lhs_cols.to_egglog(),
+            self.rhs_cols.to_egglog(),
+            ilist_egglog(&[&inputs[0].1, &inputs[1].1]),
+        )
+    }
+}
+
+impl EgglogOp for Concat2D {
+    fn sort(&self) -> SortDef {
+        sort(
+            OP_KIND,
+            "Concat2D",
+            &[
+                ("rows", EXPRESSION),
+                ("lhs_cols", EXPRESSION),
+                ("rhs_cols", EXPRESSION),
+            ],
+        )
+    }
+    fn cleanup(&self) -> bool {
+        true
+    }
+    fn n_inputs(&self) -> usize {
+        2
+    }
+    fn rewrites(&self) -> Vec<Rule> {
+        vec![dtype_propagation_op(&self.sort())]
+    }
+    fn extract<'a>(
+        &'a self,
+        egraph: &'a SerializedEGraph,
+        kind_children: &[&'a ENodeId],
+        input_enodes: Vec<&'a ENodeId>,
+        _list_cache: &mut FxHashMap<&'a ENodeId, Vec<Expression>>,
+        expr_cache: &mut FxHashMap<&'a ENodeId, Expression>,
+    ) -> (LLIROp, Vec<&'a ENodeId>) {
+        (
+            LLIROp::new::<dyn NativeOp>(Box::new(Self {
+                rows: extract_expr(egraph, kind_children[0], expr_cache).unwrap(),
+                lhs_cols: extract_expr(egraph, kind_children[1], expr_cache).unwrap(),
+                rhs_cols: extract_expr(egraph, kind_children[2], expr_cache).unwrap(),
+            })),
+            input_enodes,
+        )
+    }
+}
+
+impl NativeOp for Concat2D {
+    fn execute(&self, inputs: Vec<&NativeData>, dyn_map: &FxHashMap<char, usize>) -> NativeData {
+        let rows = self.rows.exec(dyn_map).unwrap();
+        let lhs_cols = self.lhs_cols.exec(dyn_map).unwrap();
+        let rhs_cols = self.rhs_cols.exec(dyn_map).unwrap();
+
+        fn concat_rows<T: Clone>(
+            lhs: &[T],
+            rhs: &[T],
+            rows: usize,
+            lhs_cols: usize,
+            rhs_cols: usize,
+        ) -> Vec<T> {
+            let mut out = Vec::with_capacity(rows * (lhs_cols + rhs_cols));
+            for row in 0..rows {
+                let lhs_base = row * lhs_cols;
+                let rhs_base = row * rhs_cols;
+                out.extend_from_slice(&lhs[lhs_base..lhs_base + lhs_cols]);
+                out.extend_from_slice(&rhs[rhs_base..rhs_base + rhs_cols]);
+            }
+            out
+        }
+
+        match (inputs[0], inputs[1]) {
+            (NativeData::F32(lhs), NativeData::F32(rhs)) => {
+                NativeData::F32(concat_rows(lhs, rhs, rows, lhs_cols, rhs_cols))
+            }
+            (NativeData::F16(lhs), NativeData::F16(rhs)) => {
+                NativeData::F16(concat_rows(lhs, rhs, rows, lhs_cols, rhs_cols))
+            }
+            (NativeData::Bf16(lhs), NativeData::Bf16(rhs)) => {
+                NativeData::Bf16(concat_rows(lhs, rhs, rows, lhs_cols, rhs_cols))
+            }
+            (NativeData::Int(lhs), NativeData::Int(rhs)) => {
+                NativeData::Int(concat_rows(lhs, rhs, rows, lhs_cols, rhs_cols))
+            }
+            (NativeData::Bool(lhs), NativeData::Bool(rhs)) => {
+                NativeData::Bool(concat_rows(lhs, rhs, rows, lhs_cols, rhs_cols))
+            }
+            _ => panic!("Concat2D inputs must have the same dtype"),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Default, PartialEq)]
+pub struct EmbeddingBagSum {
+    pub n_bags: Expression,
+    pub n_indices: Expression,
+    pub hidden_dim: Expression,
+    pub num_embeddings: Expression,
+}
+impl Display for EmbeddingBagSum {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "EmbeddingBagSum")
+    }
+}
+impl HLIROp for EmbeddingBagSum {
+    fn to_egglog(&self, inputs: &[(NodeIndex, String)]) -> String {
+        format!(
+            "(Op (EmbeddingBagSum {} {} {} {}) {})",
+            self.n_bags.to_egglog(),
+            self.n_indices.to_egglog(),
+            self.hidden_dim.to_egglog(),
+            self.num_embeddings.to_egglog(),
+            ilist_egglog(&[&inputs[0].1, &inputs[1].1, &inputs[2].1]),
+        )
+    }
+}
+
+impl EgglogOp for EmbeddingBagSum {
+    fn sort(&self) -> SortDef {
+        sort(
+            OP_KIND,
+            "EmbeddingBagSum",
+            &[
+                ("n_bags", EXPRESSION),
+                ("n_indices", EXPRESSION),
+                ("hidden_dim", EXPRESSION),
+                ("num_embeddings", EXPRESSION),
+            ],
+        )
+    }
+    fn cleanup(&self) -> bool {
+        true
+    }
+    fn n_inputs(&self) -> usize {
+        3
+    }
+    fn rewrites(&self) -> Vec<Rule> {
+        vec![dtype_propagation_op(&self.sort())]
+    }
+    fn extract<'a>(
+        &'a self,
+        egraph: &'a SerializedEGraph,
+        kind_children: &[&'a ENodeId],
+        input_enodes: Vec<&'a ENodeId>,
+        _list_cache: &mut FxHashMap<&'a ENodeId, Vec<Expression>>,
+        expr_cache: &mut FxHashMap<&'a ENodeId, Expression>,
+    ) -> (LLIROp, Vec<&'a ENodeId>) {
+        (
+            LLIROp::new::<dyn NativeOp>(Box::new(Self {
+                n_bags: extract_expr(egraph, kind_children[0], expr_cache).unwrap(),
+                n_indices: extract_expr(egraph, kind_children[1], expr_cache).unwrap(),
+                hidden_dim: extract_expr(egraph, kind_children[2], expr_cache).unwrap(),
+                num_embeddings: extract_expr(egraph, kind_children[3], expr_cache).unwrap(),
+            })),
+            input_enodes,
+        )
+    }
+}
+
+impl NativeOp for EmbeddingBagSum {
+    fn execute(&self, inputs: Vec<&NativeData>, dyn_map: &FxHashMap<char, usize>) -> NativeData {
+        let n_bags = self.n_bags.exec(dyn_map).unwrap();
+        let n_indices = self.n_indices.exec(dyn_map).unwrap();
+        let hidden_dim = self.hidden_dim.exec(dyn_map).unwrap();
+        let num_embeddings = self.num_embeddings.exec(dyn_map).unwrap_or(0);
+
+        let clamp_index = |value: i32, limit: usize| -> usize {
+            if limit == 0 {
+                return 0;
+            }
+            value.clamp(0, limit.saturating_sub(1) as i32) as usize
+        };
+        let clamp_offset = |value: i32| -> usize { value.clamp(0, n_indices as i32) as usize };
+
+        let NativeData::Int(indices) = inputs[1] else {
+            panic!("EmbeddingBagSum indices must be Int")
+        };
+        let NativeData::Int(offsets) = inputs[2] else {
+            panic!("EmbeddingBagSum offsets must be Int")
+        };
+
+        let bag_bounds = |bag: usize| -> (usize, usize) {
+            let start = offsets.get(bag).copied().map(clamp_offset).unwrap_or(0);
+            let end = offsets
+                .get(bag + 1)
+                .copied()
+                .map(clamp_offset)
+                .unwrap_or(n_indices);
+            (start, end.max(start))
+        };
+
+        match inputs[0] {
+            NativeData::F32(weight) => {
+                let mut out = vec![0.0f32; n_bags * hidden_dim];
+                for bag in 0..n_bags {
+                    let (start, end) = bag_bounds(bag);
+                    let out_base = bag * hidden_dim;
+                    for pos in start..end {
+                        let row = clamp_index(indices[pos], num_embeddings);
+                        let row_base = row * hidden_dim;
+                        for dim in 0..hidden_dim {
+                            out[out_base + dim] += weight[row_base + dim];
+                        }
+                    }
+                }
+                NativeData::F32(out)
+            }
+            _ => panic!("EmbeddingBagSum only supports F32 weights"),
+        }
+    }
+}
+
 // Scatter Op (inverse of Gather)
 
 #[derive(Debug, Clone, Default, PartialEq)]

src/shape/expression.rs

@@ -455,31 +455,6 @@ impl Expression {
         terms.push(Term::CeilDiv);
         Expression::new(terms)
     }
-    /// Floor Division
-    pub fn floor_div<E: Into<Expression>>(self, rhs: E) -> Self {
-        let rhs = rhs.into();
-        if rhs == 1 {
-            return self;
-        }
-        if self == 0 {
-            return 0.into();
-        }
-        if self == rhs {
-            return 1.into();
-        }
-        if let (Some(a), Some(b)) = (self.as_num(), rhs.as_num())
-            && let Some(c) = floor_div_i64(a, b)
-        {
-            return c.into();
-        }
-
-        // Shape dimensions are non-negative, so the existing integer Div term
-        // evaluates with floor semantics for dynamic shape expressions.
-        let mut terms = rhs.terms.read().clone();
-        terms.extend(self.terms.read().iter().copied());
-        terms.push(Term::Div);
-        Expression::new(terms)
-    }
     /// Less than
     pub fn lt<E: Into<Expression>>(self, rhs: E) -> Self {
         let rhs = rhs.into();
@@ -679,16 +654,6 @@ fn is_valid_rpn_expression(terms: &[Term]) -> bool {
     depth == 1
 }
 
-fn floor_div_i64(a: i64, b: i64) -> Option<i64> {
-    let q = a.checked_div(b)?;
-    let r = a.checked_rem(b)?;
-    if r != 0 && ((r > 0) != (b > 0)) {
-        q.checked_sub(1)
-    } else {
-        Some(q)
-    }
-}
-
 impl From<Term> for Expression {
     fn from(value: Term) -> Self {
         Expression::new(vec![value])
@@ -1029,12 +994,8 @@ impl<E: Into<Expression>> BitOr<E> for Expression {
 
 impl std::iter::Product for Expression {
     fn product<I: Iterator<Item = Expression>>(mut iter: I) -> Self {
-        // Empty product is the multiplicative identity, 1 — not 0. Returning
-        // 0 here breaks rank-0 tensors: every `shape.iter().product()` call
-        // site treats this as `numel`, and a `numel=0` rank-0 tensor reduces
-        // to an invalid CUDA grid (0 blocks) and a nonsensical buffer size.
         let Some(mut p) = iter.next() else {
-            return 1.into();
+            return 0.into();
         };
         for n in iter {
             p *= n;
@@ -1145,27 +1106,6 @@ mod tests {
     use super::*;
     use proptest::prelude::*;
 
-    #[test]
-    fn test_empty_product_is_one() {
-        // The empty product (e.g. for a rank-0 tensor's shape) must be the
-        // multiplicative identity, 1 — not 0. cuda_lite and other kernel
-        // emitters use `shape.iter().product()` to compute `numel`, and a
-        // rank-0 tensor has 1 element. Returning 0 here would yield a CUDA
-        // launch with grid=(0, 1, 1) and crash at runtime.
-        let empty: Vec<Expression> = vec![];
-        assert_eq!(
-            empty.into_iter().product::<Expression>(),
-            Expression::from(1)
-        );
-    }
-
-    #[test]
-    fn test_empty_sum_is_zero() {
-        // Sanity check the additive identity stays 0 (it always was).
-        let empty: Vec<Expression> = vec![];
-        assert_eq!(empty.into_iter().sum::<Expression>(), Expression::from(0));
-    }
-
     #[test]
     fn test_basic_simplifications() {
         let x = expr('x');