ggml : add ggml_top_k

ggerganov · ggerganov · commit 525040c2ccc7 · 2025-11-24T19:17:23.000+02:00
diff --git a/ggml/include/ggml.h b/ggml/include/ggml.h
@@ -530,6 +530,7 @@ extern "C" {
         GGML_OP_ARANGE,
         GGML_OP_TIMESTEP_EMBEDDING,
         GGML_OP_ARGSORT,
+        GGML_OP_TOP_K,
         GGML_OP_LEAKY_RELU,
         GGML_OP_TRI,
         GGML_OP_FILL,
diff --git a/ggml/src/ggml-cpu/ggml-cpu.c b/ggml/src/ggml-cpu/ggml-cpu.c
@@ -1927,6 +1927,10 @@ static void ggml_compute_forward(struct ggml_compute_params * params, struct ggm
             {
                 ggml_compute_forward_argsort(params, tensor);
             } break;
+        case GGML_OP_TOP_K:
+            {
+                ggml_compute_forward_top_k(params, tensor);
+            } break;
         case GGML_OP_LEAKY_RELU:
             {
                 ggml_compute_forward_leaky_relu(params, tensor);
@@ -2311,6 +2315,7 @@ static int ggml_get_n_tasks(struct ggml_tensor * node, int n_threads) {
         case GGML_OP_ARANGE:
         case GGML_OP_TIMESTEP_EMBEDDING:
         case GGML_OP_ARGSORT:
+        case GGML_OP_TOP_K:
         case GGML_OP_FLASH_ATTN_EXT:
         case GGML_OP_FLASH_ATTN_BACK:
         case GGML_OP_SSM_CONV:
@@ -2834,6 +2839,10 @@ struct ggml_cplan ggml_graph_plan(
                         cur += sizeof(ggml_fp16_t)*ne00*ne01*ne02*ne03;
                         cur += sizeof(ggml_fp16_t)*ne10*ne11*ne12;
                     } break;
+                case GGML_OP_TOP_K:
+                    {
+                        cur += sizeof(int32_t)*node->src[0]->ne[0]*n_tasks;
+                    } break;
                 case GGML_OP_FLASH_ATTN_EXT:
                     {
                         const int64_t ne10 = node->src[1]->ne[0]; // DK
diff --git a/ggml/src/ggml-cpu/ops.cpp b/ggml/src/ggml-cpu/ops.cpp
@@ -7794,7 +7794,7 @@ void ggml_compute_forward_timestep_embedding(
 // ggml_compute_forward_argsort
 
 template<enum ggml_sort_order order>
-struct argsort_cmp {
+struct cmp_argsort {
     const float * data;
     bool operator()(int32_t a, int32_t b) const {
         if constexpr (order == GGML_SORT_ORDER_ASC) {
@@ -7833,11 +7833,11 @@ static void ggml_compute_forward_argsort_f32(
 
         switch (order) {
             case GGML_SORT_ORDER_ASC:
-                std::sort(dst_data, dst_data + ne0, argsort_cmp<GGML_SORT_ORDER_ASC>{src_data});
+                std::sort(dst_data, dst_data + ne0, cmp_argsort<GGML_SORT_ORDER_ASC>{src_data});
                 break;
 
             case GGML_SORT_ORDER_DESC:
-                std::sort(dst_data, dst_data + ne0, argsort_cmp<GGML_SORT_ORDER_DESC>{src_data});
+                std::sort(dst_data, dst_data + ne0, cmp_argsort<GGML_SORT_ORDER_DESC>{src_data});
                 break;
 
             default:
@@ -7864,6 +7864,67 @@ void ggml_compute_forward_argsort(
     }
 }
 
+// ggml_compute_forward_top_k
+
+struct cmp_top_k {
+    const float * data;
+    bool operator()(int32_t a, int32_t b) const {
+        return data[a] > data[b];
+    }
+};
+
+static void ggml_compute_forward_top_k_f32(
+    const ggml_compute_params * params,
+    ggml_tensor * dst) {
+
+    const ggml_tensor * src0 = dst->src[0];
+
+    GGML_TENSOR_UNARY_OP_LOCALS
+
+    GGML_ASSERT(nb0 == sizeof(float));
+
+    const int ith = params->ith;
+    const int nth = params->nth;
+
+    const int64_t nr = ggml_nrows(src0);
+
+    const int k = ggml_get_op_params_i32(dst, 0);
+
+    int32_t * tmp = (int32_t *) params->wdata + (ne00 + CACHE_LINE_SIZE_F32) * ith;
+
+    for (int64_t i = ith; i < nr; i += nth) {
+        const float * src_data = (float *)((char *) src0->data + i*nb01);
+
+        for (int64_t j = 0; j < ne00; j++) {
+            tmp[j] = j;
+        }
+
+        std::partial_sort(tmp, tmp + k, tmp + ne00, cmp_top_k{src_data});
+
+        int32_t * dst_data = (int32_t *)((char *) dst->data + i*nb1);
+
+        std::copy(tmp, tmp + k, dst_data);
+    }
+}
+
+void ggml_compute_forward_top_k(
+    const ggml_compute_params * params,
+    ggml_tensor * dst) {
+
+    const ggml_tensor * src0 = dst->src[0];
+
+    switch (src0->type) {
+        case GGML_TYPE_F32:
+            {
+                ggml_compute_forward_top_k_f32(params, dst);
+            } break;
+        default:
+            {
+                GGML_ABORT("fatal error");
+            }
+    }
+}
+
 // ggml_compute_forward_flash_attn_ext
 
 static void ggml_compute_forward_flash_attn_ext_f16_one_chunk(
diff --git a/ggml/src/ggml-cpu/ops.h b/ggml/src/ggml-cpu/ops.h
@@ -81,6 +81,7 @@ void ggml_compute_forward_roll(const struct ggml_compute_params * params, struct
 void ggml_compute_forward_arange(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_timestep_embedding(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_argsort(const struct ggml_compute_params * params, struct ggml_tensor * dst);
+void ggml_compute_forward_top_k(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_leaky_relu(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_tri(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_fill(const struct ggml_compute_params * params, struct ggml_tensor * dst);
diff --git a/ggml/src/ggml.c b/ggml/src/ggml.c
@@ -990,6 +990,7 @@ static const char * GGML_OP_NAME[GGML_OP_COUNT] = {
     "ARANGE",
     "TIMESTEP_EMBEDDING",
     "ARGSORT",
+    "TOP_K",
     "LEAKY_RELU",
     "TRI",
     "FILL",
@@ -1023,7 +1024,7 @@ static const char * GGML_OP_NAME[GGML_OP_COUNT] = {
     "GLU",
 };
 
-static_assert(GGML_OP_COUNT == 94, "GGML_OP_COUNT != 94");
+static_assert(GGML_OP_COUNT == 95, "GGML_OP_COUNT != 95");
 
 static const char * GGML_OP_SYMBOL[GGML_OP_COUNT] = {
     "none",
@@ -1098,6 +1099,7 @@ static const char * GGML_OP_SYMBOL[GGML_OP_COUNT] = {
     "arange(start, stop, step)",
     "timestep_embedding(timesteps, dim, max_period)",
     "argsort(x)",
+    "top_k(x)",
     "leaky_relu(x)",
     "tri(x)",
     "fill(x, c)",
@@ -1131,7 +1133,7 @@ static const char * GGML_OP_SYMBOL[GGML_OP_COUNT] = {
     "glu(x)",
 };
 
-static_assert(GGML_OP_COUNT == 94, "GGML_OP_COUNT != 94");
+static_assert(GGML_OP_COUNT == 95, "GGML_OP_COUNT != 95");
 
 static_assert(GGML_OP_POOL_COUNT == 2, "GGML_OP_POOL_COUNT != 2");
 
@@ -5139,6 +5141,7 @@ struct ggml_tensor * ggml_argsort(
         struct ggml_tensor   * a,
         enum ggml_sort_order   order) {
     GGML_ASSERT(a->ne[0] <= INT32_MAX);
+
     struct ggml_tensor * result = ggml_new_tensor(ctx, GGML_TYPE_I32, GGML_MAX_DIMS, a->ne);
 
     ggml_set_op_params_i32(result, 0, (int32_t) order);
@@ -5157,12 +5160,12 @@ struct ggml_tensor * ggml_top_k(
         int                   k) {
     GGML_ASSERT(a->ne[0] >= k);
 
-    struct ggml_tensor * result = ggml_argsort(ctx, a, GGML_SORT_ORDER_DESC);
+    struct ggml_tensor * result = ggml_new_tensor_4d(ctx, GGML_TYPE_I32, k, a->ne[1], a->ne[2], a->ne[3]);
+
+    ggml_set_op_params_i32(result, 0, (int32_t) k);
 
-    result = ggml_view_4d(ctx, result,
-                k, result->ne[1], result->ne[2], result->ne[3],
-                   result->nb[1], result->nb[2], result->nb[3],
-                0);
+    result->op     = GGML_OP_TOP_K;
+    result->src[0] = a;
 
     return result;
 }
