ggml : add GGML_OP_LIGHTNING_INDEXER that implements DeepSeek V3.2/V4 lightning indexer (#24231)

* ggml : add GGML_OP_LIGHTNING_INDEXER that implements DeepSeek V3.2/V4 lightning indexer

* ggml : remove scale parameters from lightning indexer OP, add f16 mask parameter

* tests : add GGML_OP_LIGHTNING_INDEXER tests

* ggml : bump RPC version

* chore : check if lightning indexer input tensors are not transposed

* tests : count flops instead of bandwidth in lightning indexer test

* chore : add missing const

* chore : whitespace

* ggml : renamed variables in CPU lightning indexer implementation

* ggml : fix lightning indexer mask broadcasting

* tests : tests for lightning indexer mask broadcasting

* chore : whitespace

* llama : use GGML_OP_LIGHTNING_INDEXER in DeepSeek V3.2 and DeepSeek V4 models

---------

Co-authored-by: Stanisław Szymczyk <sszymczy@gmail.com>

ggml/include/ggml-rpc.h

@@ -8,10 +8,10 @@ extern "C" {
 
 #define RPC_PROTO_MAJOR_VERSION    4
 #define RPC_PROTO_MINOR_VERSION    0
-#define RPC_PROTO_PATCH_VERSION    1
+#define RPC_PROTO_PATCH_VERSION    2
 
 #ifdef  __cplusplus
-static_assert(GGML_OP_COUNT == 97, "GGML_OP_COUNT has changed - update RPC_PROTO_PATCH_VERSION");
+static_assert(GGML_OP_COUNT == 98, "GGML_OP_COUNT has changed - update RPC_PROTO_PATCH_VERSION");
 #endif
 
 #define GGML_RPC_MAX_SERVERS       16

ggml/include/ggml.h

@@ -570,6 +570,7 @@ extern "C" {
         GGML_OP_RWKV_WKV7,
         GGML_OP_SOLVE_TRI,
         GGML_OP_GATED_DELTA_NET,
+        GGML_OP_LIGHTNING_INDEXER,
 
         GGML_OP_UNARY,
 
@@ -2575,6 +2576,24 @@ extern "C" {
             struct ggml_tensor  * state,
             int64_t               K);
 
+    // DSA lightning indexer
+    //
+    // q:       [n_embd_idx, n_head_idx, n_batch, ne3 ]
+    // k:       [n_embd_idx, 1,          n_kv,    ne3 ]
+    // weights: [n_head_idx, n_batch,    1,       ne3 ] !! prescaled !!
+    // mask:    [n_kv,       n_batch,    1,       ne33] !! f16 !!
+    // res:     [n_kv,       n_batch,    1,       ne3 ]
+    //
+    // broadcast:
+    //   ne3 % ne33 == 0
+    //
+    GGML_API struct ggml_tensor * ggml_lightning_indexer(
+        struct ggml_context * ctx,
+        struct ggml_tensor  * q,
+        struct ggml_tensor  * k,
+        struct ggml_tensor  * weights,
+        struct ggml_tensor  * mask);
+
     // custom operators
 
     typedef void (*ggml_custom1_op_t)(struct ggml_tensor * dst , const struct ggml_tensor * a, int ith, int nth, void * userdata);

ggml/src/ggml-cpu/ggml-cpu.c

@@ -2060,6 +2060,10 @@ static void ggml_compute_forward(struct ggml_compute_params * params, struct ggm
             {
                 ggml_compute_forward_gated_delta_net(params, tensor);
             } break;
+        case GGML_OP_LIGHTNING_INDEXER:
+            {
+                ggml_compute_forward_lightning_indexer(params, tensor);
+            } break;
         case GGML_OP_MAP_CUSTOM1:
             {
                 ggml_compute_forward_map_custom1(params, tensor);
@@ -2380,6 +2384,7 @@ static int ggml_get_n_tasks(struct ggml_tensor * node, int n_threads) {
         case GGML_OP_FLASH_ATTN_BACK:
         case GGML_OP_SSM_CONV:
         case GGML_OP_SSM_SCAN:
+        case GGML_OP_LIGHTNING_INDEXER:
             {
                 n_tasks = n_threads;
             } break;
@@ -2965,6 +2970,12 @@ struct ggml_cplan ggml_graph_plan(
                     {
                         GGML_ABORT("fatal error");
                     }
+                case GGML_OP_LIGHTNING_INDEXER:
+                    {
+                        // temp buffer for dequantizing lightning indexer keys
+                        const int64_t ne10 = node->src[1]->ne[0];
+                        cur += sizeof(float)*ne10*n_tasks;
+                    } break;
                 default:
                     break;
             }

ggml/src/ggml-cpu/ops.cpp

@@ -11568,3 +11568,87 @@ void ggml_compute_forward_fwht(const ggml_compute_params * params, ggml_tensor *
             }
     }
 }
+
+// ggml_compute_forward_lightning_indexer
+
+void ggml_compute_forward_lightning_indexer(
+        const ggml_compute_params * params,
+        ggml_tensor * dst) {
+
+    const ggml_tensor * q = dst->src[0];
+    const ggml_tensor * k = dst->src[1];
+    const ggml_tensor * w = dst->src[2]; // weights
+    const ggml_tensor * m = dst->src[3]; // mask
+
+    GGML_ASSERT(dst->type  == GGML_TYPE_F32);
+    GGML_ASSERT(   q->type == GGML_TYPE_F32);
+    GGML_ASSERT(   w->type == GGML_TYPE_F32);
+    GGML_ASSERT(   m->type == GGML_TYPE_F16);
+
+    GGML_TENSOR_LOCALS(int64_t, neq,  q, ne)
+    GGML_TENSOR_LOCALS(size_t,  nbq,  q, nb)
+    GGML_TENSOR_LOCALS(int64_t, nek,  k, ne)
+    GGML_TENSOR_LOCALS(size_t,  nbk,  k, nb)
+    GGML_TENSOR_LOCALS(int64_t, new,  w, ne)
+    GGML_TENSOR_LOCALS(size_t,  nbw,  w, nb)
+    GGML_TENSOR_LOCALS(int64_t, nem,  m, ne)
+    GGML_TENSOR_LOCALS(size_t,  nbm,  m, nb)
+    GGML_TENSOR_LOCALS(int64_t, ne, dst, ne)
+    GGML_TENSOR_LOCALS(size_t,  nb, dst, nb)
+
+    GGML_ASSERT( nb0 == ggml_type_size(dst->type));
+    GGML_ASSERT(nbq0 == ggml_type_size(  q->type));
+    GGML_ASSERT(nbk0 == ggml_type_size(  k->type));
+    GGML_ASSERT(nbw0 == ggml_type_size(  w->type));
+    GGML_ASSERT(nbm0 == ggml_type_size(  m->type));
+
+    const int n_embd    = q->ne[0];
+    const int n_head    = q->ne[1];
+    const int n_tokens  = q->ne[2];
+    const int n_stream  = q->ne[3];
+    const int n_kv      = k->ne[2];
+
+    ggml_to_float_t const k_to_float = ggml_get_type_traits(k->type)->to_float;
+    GGML_ASSERT((k->type == GGML_TYPE_F32 || k_to_float) && "lightning indexer: unsupported K-type");
+
+    const int nr  = n_kv;
+    const int ith = params->ith;
+    const int nth = params->nth;
+
+    // (temporary) buffer for K converted to float
+    float * k_row_f32 = (float *) params->wdata + ith*(1*n_embd + CACHE_LINE_SIZE_F32);
+
+    // rows per thread
+    const int dr = (nr + nth - 1)/nth;
+
+    // row range for this thread
+    const int ir0 = dr*ith;
+    const int ir1 = MIN(ir0 + dr, nr);
+
+    for (int s = 0; s < n_stream; ++s) {
+        for (int t = 0; t < n_tokens; ++t) {
+            const float       *   w_row =       (float *) ((char *)   w->data + t*nbw1 +        s*nbw3);
+            const ggml_fp16_t *   m_row = (ggml_fp16_t *) ((char *)   m->data + t*nbm1 + (s%nem3)*nbm3);
+            float             * dst_row =       (float *) ((char *) dst->data + t*nb1  +        s*nb3 );
+            for (int ik = ir0; ik < ir1; ++ik) {
+                char * k_row = (char *) k->data + ik*nbk2 + s*nbk3;
+                if (k_to_float) {
+                    k_to_float(k_row, k_row_f32, n_embd);
+                } else {
+                    k_row_f32 = (float *) k_row;
+                }
+                float score = 0.0f;
+                for (int h = 0; h < n_head; ++h) {
+                    // dot product of q and k for head h
+                    float qk = 0.0f;
+                    const float * q_row = (float *) ((char *) q->data + h*nbq1 + t*nbq2 + s*nbq3);
+                    ggml_vec_dot_f32(n_embd, &qk, 0, q_row, 0, k_row_f32, 0, 1);
+                    // ReLU and weights (prescaled)
+                    score += MAX(qk, 0.0f) * w_row[h];
+                }
+                // apply mask
+                dst_row[ik] = score + GGML_CPU_FP16_TO_FP32(m_row[ik]);
+            }
+        }
+    }
+}

ggml/src/ggml-cpu/ops.h

@@ -105,6 +105,7 @@ void ggml_compute_forward_rwkv_wkv7(const struct ggml_compute_params * params, s
 void ggml_compute_forward_solve_tri(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_gla(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_gated_delta_net(const struct ggml_compute_params * params, struct ggml_tensor * dst);
+void ggml_compute_forward_lightning_indexer(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_map_custom1(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_map_custom2(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_map_custom3(const struct ggml_compute_params * params, struct ggml_tensor * dst);

ggml/src/ggml.c

@@ -1079,6 +1079,7 @@ static const char * GGML_OP_NAME[GGML_OP_COUNT] = {
     "RWKV_WKV7",
     "SOLVE_TRI",
     "GATED_DELTA_NET",
+    "LIGHTNING_INDEXER",
 
     "UNARY",
 
@@ -1096,7 +1097,7 @@ static const char * GGML_OP_NAME[GGML_OP_COUNT] = {
     "GLU",
 };
 
-static_assert(GGML_OP_COUNT == 97, "GGML_OP_COUNT != 97");
+static_assert(GGML_OP_COUNT == 98, "GGML_OP_COUNT != 98");
 
 static const char * GGML_OP_SYMBOL[GGML_OP_COUNT] = {
     "none",
@@ -1190,6 +1191,7 @@ static const char * GGML_OP_SYMBOL[GGML_OP_COUNT] = {
     "rwkv_wkv7(r, w, k, v, a, b, s)",
     "A X = B, A triangular, solve X",
     "gated_delta_net(q, k, v, g, beta, s)",
+    "lightning_indexer(q, k, weights, mask)",
 
     "unary(x)",
 
@@ -1207,7 +1209,7 @@ static const char * GGML_OP_SYMBOL[GGML_OP_COUNT] = {
     "glu(x)",
 };
 
-static_assert(GGML_OP_COUNT == 97, "GGML_OP_COUNT != 97");
+static_assert(GGML_OP_COUNT == 98, "GGML_OP_COUNT != 98");
 
 static_assert(GGML_OP_POOL_COUNT == 2, "GGML_OP_POOL_COUNT != 2");
 
@@ -6287,6 +6289,42 @@ struct ggml_tensor * ggml_gated_delta_net(
     return result;
 }
 
+// ggml_lightning_indexer
+
+struct ggml_tensor * ggml_lightning_indexer(
+        struct ggml_context * ctx,
+        struct ggml_tensor  * q,
+        struct ggml_tensor  * k,
+        struct ggml_tensor  * weights,
+        struct ggml_tensor  * mask) {
+
+    GGML_ASSERT(       q->type == GGML_TYPE_F32);
+    GGML_ASSERT( weights->type == GGML_TYPE_F32);
+    GGML_ASSERT(    mask->type == GGML_TYPE_F16);
+    GGML_ASSERT(      q->ne[0] == k->ne[0]);
+    GGML_ASSERT(   mask->ne[0] == k->ne[2]);
+    GGML_ASSERT(      q->ne[1] == weights->ne[0]);
+    GGML_ASSERT(      k->ne[1] == 1);
+    GGML_ASSERT(   mask->ne[1] == q->ne[2]);
+    GGML_ASSERT(      q->ne[2] == weights->ne[1]);
+    GGML_ASSERT(weights->ne[2] == 1);
+    GGML_ASSERT(   mask->ne[2] == 1);
+    GGML_ASSERT(      q->ne[3] == k->ne[3]);
+    GGML_ASSERT(      k->ne[3] == weights->ne[3]);
+    GGML_ASSERT(weights->ne[3] % mask->ne[3] == 0);
+
+    int64_t ne[4] = { k->ne[2], q->ne[2], 1, q->ne[3] };
+    struct ggml_tensor * result = ggml_new_tensor(ctx, GGML_TYPE_F32, 4, ne);
+
+    result->op   = GGML_OP_LIGHTNING_INDEXER;
+    result->src[0] = q;
+    result->src[1] = k;
+    result->src[2] = weights;
+    result->src[3] = mask;
+
+    return result;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 struct ggml_hash_set ggml_hash_set_new(size_t size) {

src/llama-context.cpp

@@ -55,6 +55,12 @@ static const llm_fused_op_probe llm_fused_op_gdn_ch_probe = {
     /*.n_tokens_per_seq =*/ 16,
 };
 
+static const llm_fused_op_probe llm_fused_op_lid_probe = {
+    /*.op               =*/ LLM_FUSED_OP_LIGHTNING_INDEXER,
+    /*.name             =*/ "Lightning Indexer",
+    /*.n_tokens_per_seq =*/ 1,
+};
+
 llama_context::llama_context(
         const llama_model & model,
               llama_context_params params) :
@@ -226,6 +232,9 @@ llama_context::llama_context(
     cparams.fused_gdn_ch = true;
     cparams.auto_fgdn    = true;
 
+    cparams.fused_lid    = true;
+    cparams.auto_flid    = true;
+
     // with causal attention, the batch size is limited by the context size
     cparams.n_batch = cparams.causal_attn ? std::min(cparams.n_ctx, params.n_batch) : params.n_batch;
 
@@ -522,6 +531,12 @@ void llama_context::resolve_fused_ops(const llama_memory_context_i * mctx, uint3
         resolve(llm_fused_op_gdn_ch_probe, cparams.fused_gdn_ch);
         cparams.auto_fgdn = false;
     }
+
+    if (cparams.auto_flid) {
+        LLAMA_LOG_INFO("%s: resolving fused Lightning Indexer support:\n", func);
+        resolve(llm_fused_op_lid_probe, cparams.fused_lid);
+        cparams.auto_flid = false;
+    }
 }
 
 void llama_context::sched_reserve() {

src/llama-cparams.h

@@ -41,6 +41,8 @@ struct llama_cparams {
     bool fused_gdn_ar;       // use fused gated delta net (autoregressive)
     bool fused_gdn_ch;       // use fused gated delta net (chunked)
     bool auto_fgdn;
+    bool fused_lid;          // use fused lightning indexer
+    bool auto_flid;
     bool no_perf;
     bool warmup;             // TODO: remove [TAG_LLAMA_GRAPH_NO_WARMUP]
     bool op_offload;

src/llama-graph.cpp

@@ -842,7 +842,7 @@ static void dsv4_build_comp_inputs(
         GGML_ASSERT(n_stream > 0);
         GGML_ASSERT(n_tokens%n_stream == 0);
 
-        inp.kq_mask = ggml_new_tensor_4d(ctx, cparams.flash_attn && strcmp(name, "lid") != 0 ? GGML_TYPE_F16 : GGML_TYPE_F32, plan.n_kv, n_tokens/n_stream, 1, n_stream);
+        inp.kq_mask = ggml_new_tensor_4d(ctx, (strcmp(name, "lid") != 0 && cparams.flash_attn) || (strcmp(name, "lid") == 0 && cparams.fused_lid) ? GGML_TYPE_F16 : GGML_TYPE_F32, plan.n_kv, n_tokens/n_stream, 1, n_stream);
         ggml_set_input(inp.kq_mask);
         ggml_set_name(inp.kq_mask, (std::string("dsv4_") + name + "_kq_mask").c_str());
     }
@@ -3025,9 +3025,9 @@ llm_graph_input_attn_k_dsa * llm_graph_context::build_attn_inp_k_dsa() const {
     {
         inp->self_k_idxs_lid = mctx_cur->get_lid()->build_input_k_idxs(ctx0, ubatch);
 
-        // ensure F32 mask
+        // ensure that mask type matches fused lightning indexer use (requires f16 mask)
         auto cparams_copy = cparams;
-        cparams_copy.flash_attn = false;
+        cparams_copy.flash_attn = cparams.fused_lid;
 
         inp->self_kq_mask_lid = build_attn_inp_kq_mask(ctx0, mctx_cur->get_lid(), ubatch, cparams_copy);
         inp->self_kq_mask_lid_cnv = inp->self_kq_mask_lid;

src/llama-graph.h

@@ -42,6 +42,7 @@ enum llm_fused_op {
     LLM_FUSED_OP_FLASH_ATTN,
     LLM_FUSED_OP_GDN_AR,
     LLM_FUSED_OP_GDN_CH,
+    LLM_FUSED_OP_LIGHTNING_INDEXER,
 };
 
 enum llm_ffn_op_type : int {

src/models/deepseek32.cpp

@@ -301,43 +301,50 @@ llama_model_deepseek32::graph::graph(const llama_model & model, const llm_graph_
                 indexer_q = ggml_view_4d(ctx0, indexer_q, indexer_q->ne[0], indexer_q->ne[1], indexer_q->ne[2]/n_stream, n_stream, indexer_q->nb[1], indexer_q->nb[2], indexer_q->nb[3]/n_stream, 0);
                 indexer_weights = ggml_view_4d(ctx0, indexer_weights, indexer_weights->ne[0], indexer_weights->ne[1]/n_stream, indexer_weights->ne[2], n_stream, indexer_weights->nb[1], indexer_weights->nb[2]/n_stream, indexer_weights->nb[3]/n_stream, 0);
 
-                // calculate indexer kq
-                indexer_q = ggml_permute(ctx0, indexer_q, 0, 2, 1, 3);
-                cb(indexer_q, "indexer_q", il);
-                indexer_k = ggml_permute(ctx0, indexer_k, 0, 2, 1, 3);
-                cb(indexer_k, "indexer_k", il);
-
-                ggml_tensor * indexer_kq = ggml_mul_mat(ctx0, indexer_k, indexer_q);
-                cb(indexer_kq, "indexer_kq", il);
-
-                // ReLU requires contiguous tensors
-                indexer_kq = ggml_cont(ctx0, ggml_permute(ctx0, indexer_kq, 2, 1, 0, 3));
-                cb(indexer_kq, "indexer_kq", il);
-
-                // apply ReLU
-                ggml_tensor * indexer_score = ggml_relu(ctx0, indexer_kq);
-                cb(indexer_score, "indexer_score", il);
-
                 // pre-scale weights to avoid scaling operations on huge indexer_score tensor
                 indexer_weights = ggml_scale(ctx0, indexer_weights, 1.0f / sqrtf(float(n_embd_indexer_head * n_indexer_head)));
                 cb(indexer_weights, "indexer_weights", il);
 
-                // multiply scores by indexer weights
-                indexer_score = ggml_mul(ctx0, indexer_score, indexer_weights);
-                cb(indexer_score, "indexer_score", il);
+                ggml_tensor * indexer_score = nullptr;
+                if (cparams.fused_lid) {
+                    indexer_score = ggml_lightning_indexer(ctx0, indexer_q, indexer_k, indexer_weights, inp_attn_dsa->get_kq_mask_lid());
+                    cb(indexer_score, "indexer_score", il);
+                    res->add_fused_node({LLM_FUSED_OP_LIGHTNING_INDEXER, indexer_score, il});
+                } else {
+                    // calculate indexer kq
+                    indexer_q = ggml_permute(ctx0, indexer_q, 0, 2, 1, 3);
+                    cb(indexer_q, "indexer_q", il);
+                    indexer_k = ggml_permute(ctx0, indexer_k, 0, 2, 1, 3);
+                    cb(indexer_k, "indexer_k", il);
 
-                // sum by q n_indexer_head dimension
-                indexer_score = ggml_sum_rows(ctx0, indexer_score);
-                cb(indexer_score, "indexer_score", il);
+                    ggml_tensor * indexer_kq = ggml_mul_mat(ctx0, indexer_k, indexer_q);
+                    cb(indexer_kq, "indexer_kq", il);
 
-                // permute result to match KQ mask
-                indexer_score = ggml_cont(ctx0, ggml_permute(ctx0, indexer_score, 2, 1, 0, 3));
-                cb(indexer_score, "indexer_score", il);
+                    // ReLU requires contiguous tensors
+                    indexer_kq = ggml_cont(ctx0, ggml_permute(ctx0, indexer_kq, 2, 1, 0, 3));
+                    cb(indexer_kq, "indexer_kq", il);
 
-                // mask indexer scores
-                ggml_tensor * indexer_kq_mask = inp_attn_dsa->get_kq_mask_lid();
-                indexer_score = ggml_add(ctx0, indexer_score, indexer_kq_mask);
-                cb(indexer_score, "indexer_score", il);
+                    // apply ReLU
+                    indexer_score = ggml_relu(ctx0, indexer_kq);
+                    cb(indexer_score, "indexer_score", il);
+
+                    // multiply scores by indexer weights
+                    indexer_score = ggml_mul(ctx0, indexer_score, indexer_weights);
+                    cb(indexer_score, "indexer_score", il);
+
+                    // sum by q n_indexer_head dimension
+                    indexer_score = ggml_sum_rows(ctx0, indexer_score);
+                    cb(indexer_score, "indexer_score", il);
+
+                    // permute result to match KQ mask
+                    indexer_score = ggml_cont(ctx0, ggml_permute(ctx0, indexer_score, 2, 1, 0, 3));
+                    cb(indexer_score, "indexer_score", il);
+
+                    // mask indexer scores
+                    ggml_tensor * indexer_kq_mask = inp_attn_dsa->get_kq_mask_lid();
+                    indexer_score = ggml_add(ctx0, indexer_score, indexer_kq_mask);
+                    cb(indexer_score, "indexer_score", il);
+                }
 
                 // get indices of top k indexer scores
                 uint32_t n_top_k = indexer_score->ne[0] < n_indexer_top_k ? indexer_score->ne[0] : n_indexer_top_k;

src/models/deepseek4.cpp

@@ -556,25 +556,32 @@ ggml_tensor * llama_model_deepseek4::graph::build_lid_top_k(
             indexer_weights->ne[0], indexer_weights->ne[1]/n_stream, indexer_weights->ne[2], n_stream,
             indexer_weights->nb[1], indexer_weights->nb[2]/n_stream, indexer_weights->nb[3]/n_stream, 0);
 
-    indexer_q = ggml_permute(ctx0, indexer_q, 0, 2, 1, 3);
-    cb(indexer_q, "lid_q", il);
-    indexer_k = ggml_permute(ctx0, indexer_k, 0, 2, 1, 3);
-    cb(indexer_k, "lid_k", il);
+    ggml_tensor * indexer_score = nullptr;
+    if (cparams.fused_lid) {
+        indexer_score = ggml_lightning_indexer(ctx0, indexer_q, indexer_k, indexer_weights, inp_lid.kq_mask);
+        cb(indexer_score, "lid_score_masked", il);
+        res->add_fused_node({LLM_FUSED_OP_LIGHTNING_INDEXER, indexer_score, il});
+    } else {
+        indexer_q = ggml_permute(ctx0, indexer_q, 0, 2, 1, 3);
+        cb(indexer_q, "lid_q", il);
+        indexer_k = ggml_permute(ctx0, indexer_k, 0, 2, 1, 3);
+        cb(indexer_k, "lid_k", il);
 
-    ggml_tensor * indexer_kq = ggml_mul_mat(ctx0, indexer_k, indexer_q);
-    cb(indexer_kq, "lid_kq", il);
+        ggml_tensor * indexer_kq = ggml_mul_mat(ctx0, indexer_k, indexer_q);
+        cb(indexer_kq, "lid_kq", il);
 
-    indexer_kq = ggml_cont(ctx0, ggml_permute(ctx0, indexer_kq, 2, 1, 0, 3));
-    cb(indexer_kq, "lid_kq", il);
+        indexer_kq = ggml_cont(ctx0, ggml_permute(ctx0, indexer_kq, 2, 1, 0, 3));
+        cb(indexer_kq, "lid_kq", il);
 
-    ggml_tensor * indexer_score = ggml_relu(ctx0, indexer_kq);
-    indexer_score = ggml_mul(ctx0, indexer_score, indexer_weights);
-    indexer_score = ggml_sum_rows(ctx0, indexer_score);
-    indexer_score = ggml_cont(ctx0, ggml_permute(ctx0, indexer_score, 2, 1, 0, 3));
-    cb(indexer_score, "lid_score", il);
+        indexer_score = ggml_relu(ctx0, indexer_kq);
+        indexer_score = ggml_mul(ctx0, indexer_score, indexer_weights);
+        indexer_score = ggml_sum_rows(ctx0, indexer_score);
+        indexer_score = ggml_cont(ctx0, ggml_permute(ctx0, indexer_score, 2, 1, 0, 3));
+        cb(indexer_score, "lid_score", il);
 
-    indexer_score = ggml_add(ctx0, indexer_score, inp_lid.kq_mask);
-    cb(indexer_score, "lid_score_masked", il);
+        indexer_score = ggml_add(ctx0, indexer_score, inp_lid.kq_mask);
+        cb(indexer_score, "lid_score_masked", il);
+    }
 
     const uint32_t n_top_k = indexer_score->ne[0] < hparams.indexer_top_k ? indexer_score->ne[0] : hparams.indexer_top_k;
     ggml_tensor * top_k = ggml_cont(ctx0, ggml_top_k(ctx0, indexer_score, n_top_k));

tests/test-backend-ops.cpp

@@ -7097,6 +7097,67 @@ struct test_diag : public test_case {
     }
 };
 
+// GGML_OP_LIGHTNING_INDEXER
+struct test_lightning_indexer : public test_case {
+    const int64_t hsk; // indexer K head size
+    const int64_t nh; // num indexer heads
+    const int64_t kv; // kv size
+    const int64_t nb; // batch size
+    const int64_t ns; // num streams
+    const int64_t nm; // ne[3] of mask
+
+    const ggml_type type_K;
+
+    std::string vars() override {
+        return VARS_TO_STR7(hsk, nh, kv, nb, ns, nm, type_K);
+    }
+
+    double max_nmse_err() override {
+        return 1e-6;
+    }
+
+    uint64_t op_flops(ggml_tensor * t) override {
+        GGML_UNUSED(t);
+        return ((2 * hsk + 2) * nh + 1) * kv * nb * ns;
+    }
+
+    test_lightning_indexer(int64_t hsk = 128, int64_t nh = 64, int64_t kv = 256, int64_t nb = 128, int64_t ns = 1, int64_t nm = 1, ggml_type type_K = GGML_TYPE_F16)
+        : hsk(hsk), nh(nh), kv(kv), nb(nb), ns(ns), nm(nm), type_K(type_K) {}
+
+    ggml_tensor * build_graph(ggml_context * ctx) override {
+        ggml_tensor * q = ggml_new_tensor_4d(ctx, GGML_TYPE_F32, hsk, nh, nb, ns);
+        ggml_set_param(q);
+        ggml_set_name(q, "q");
+
+        ggml_tensor * k = ggml_new_tensor_4d(ctx, type_K, hsk, 1, kv, ns);
+        ggml_set_param(k);
+        ggml_set_name(k, "k");
+
+        ggml_tensor * w = ggml_new_tensor_4d(ctx, GGML_TYPE_F32, nh, nb, 1, ns);
+        ggml_set_param(w);
+        ggml_set_name(w, "w");
+
+        ggml_tensor * m = ggml_new_tensor_4d(ctx, GGML_TYPE_F16, kv, nb, 1, nm);
+        ggml_set_param(m);
+        ggml_set_name(m, "m");
+
+        ggml_tensor * out = ggml_lightning_indexer(ctx, q, k, w, m);
+        ggml_set_name(out, "out");
+
+        return out;
+    }
+
+    void initialize_tensors(ggml_context * ctx) override {
+        for (ggml_tensor * t = ggml_get_first_tensor(ctx); t != NULL; t = ggml_get_next_tensor(ctx, t)) {
+            if (strcmp(t->name, "m") == 0) {
+                init_tensor_kq_mask(t);
+            } else {
+                init_tensor_uniform(t);
+            }
+        }
+    }
+};
+
 // Deserializable generic test case
 struct input_tensor {
     ggml_type type;
@@ -9393,6 +9454,19 @@ static std::vector<std::unique_ptr<test_case>> make_test_cases_eval() {
     test_cases.emplace_back(new test_falcon(2));
 #endif
 
+    // lightning_indexer
+    for (int kv : { 256 }) {
+        for (int bs : { 1, 512 }) {
+            for (int nh : { 32, 64 }) {
+                for (auto [ns, nm] : { std::pair{1, 1}, std::pair{4, 4}, std::pair{4, 1} }) {
+                    for (ggml_type type_K : {GGML_TYPE_F32, GGML_TYPE_F16, GGML_TYPE_BF16, GGML_TYPE_Q8_0, GGML_TYPE_Q5_1, GGML_TYPE_Q5_0, GGML_TYPE_Q4_1, GGML_TYPE_Q4_0, GGML_TYPE_IQ4_NL}) {
+                        test_cases.emplace_back(new test_lightning_indexer(128, nh, kv, bs, ns, nm, type_K));
+                    }
+                }
+            }
+        }
+    }
+
     return test_cases;
 }
 #ifdef _MSC_VER
@@ -9722,6 +9796,19 @@ static std::vector<std::unique_ptr<test_case>> make_test_cases_perf() {
     test_cases.emplace_back(new test_gated_delta_net(GGML_TYPE_F32, 4, 128, 1024, 1)); // 4h PP-1024
     test_cases.emplace_back(new test_gated_delta_net(GGML_TYPE_F32, 32, 128, 64, 1, 1, false, true)); // KDA PP-64
 
+    // lightning_indexer
+    for (int kv : { 256, 4096, 65536 }) {
+        for (int bs : { 1, 512, 2048 }) {
+            for (int nh : { 32, 64 }) {
+                for (int ns : { 1, 4 }) {
+                    for (ggml_type type_K : {GGML_TYPE_F32, GGML_TYPE_F16, GGML_TYPE_BF16, GGML_TYPE_Q8_0, GGML_TYPE_Q5_1, GGML_TYPE_Q5_0, GGML_TYPE_Q4_1, GGML_TYPE_Q4_0, GGML_TYPE_IQ4_NL}) {
+                        test_cases.emplace_back(new test_lightning_indexer(128, nh, kv, bs, ns, ns, type_K));
+                    }
+                }
+            }
+        }
+    }
+
     return test_cases;
 }