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/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) {