context : only sort outputs when needed

src/llama-context.cpp

@@ -516,8 +516,6 @@ float * llama_context::get_logits() {
 float * llama_context::get_logits_ith(int32_t i) {
     int64_t j = -1;
 
-    output_reorder();
-
     try {
         if (logits == nullptr) {
             throw std::runtime_error("no logits");
@@ -562,8 +560,6 @@ float * llama_context::get_embeddings() {
 float * llama_context::get_embeddings_ith(int32_t i) {
     int64_t j = -1;
 
-    output_reorder();
-
     try {
         if (embd == nullptr) {
             throw std::runtime_error("no embeddings");
@@ -978,7 +974,6 @@ int llama_context::decode(const llama_batch & batch_inp) {
 
     // TODO: this clear of the buffer can easily be forgotten - need something better
     embd_seq.clear();
-    output_swaps.clear();
 
     bool did_optimize = false;
 
@@ -1195,34 +1190,8 @@ int llama_context::decode(const llama_batch & batch_inp) {
             }
         }
 
-        // make the outputs have the same order they had in the user-provided batch
+        if (sorted_output) {
-        // note: this is mostly relevant for recurrent models atm
+            out_ids.clear();
-        if (!sorted_output) {
-            GGML_ASSERT((size_t) n_outputs == out_ids.size());
-
-            // TODO: is there something more efficient which also minimizes swaps?
-            // selection sort, to minimize swaps (from https://en.wikipedia.org/wiki/Selection_sort)
-            for (uint32_t i = 0; i < n_outputs - 1; ++i) {
-                uint32_t j_min = i;
-                for (uint32_t j = i + 1; j < n_outputs; ++j) {
-                    if (out_ids[j] < out_ids[j_min]) {
-                        j_min = j;
-                    }
-                }
-                if (j_min == i) {
-                    continue;
-                }
-                std::swap(out_ids[i], out_ids[j_min]);
-
-                // remember the swaps and apply them lazily upon logits/embeddings access
-                output_swaps.push_back({ i, j_min });
-            }
-
-            std::fill(output_ids.begin(), output_ids.end(), -1);
-
-            for (uint32_t i = 0; i < n_outputs; ++i) {
-                output_ids[out_ids[i]] = i;
-            }
         }
     }
 
@@ -1307,27 +1276,49 @@ uint32_t llama_context::output_reserve(int32_t n_outputs) {
 }
 
 void llama_context::output_reorder() {
+    auto & out_ids = balloc->get_out_ids();
+
+    if (!out_ids.empty()) {
         const uint32_t n_vocab = model.vocab.n_tokens();
         const uint64_t n_embd  = model.hparams.n_embd;
 
-    for (uint32_t s = 0; s < output_swaps.size(); ++s) {
+        GGML_ASSERT((size_t) n_outputs == out_ids.size());
-        const uint32_t i0 = output_swaps[s].i0;
+
-        const uint32_t i1 = output_swaps[s].i1;
+        // TODO: is there something more efficient which also minimizes swaps?
+        // selection sort, to minimize swaps (from https://en.wikipedia.org/wiki/Selection_sort)
+        for (uint32_t i = 0; i < n_outputs - 1; ++i) {
+            uint32_t j_min = i;
+            for (uint32_t j = i + 1; j < n_outputs; ++j) {
+                if (out_ids[j] < out_ids[j_min]) {
+                    j_min = j;
+                }
+            }
+            if (j_min == i) {
+                continue;
+            }
+            std::swap(out_ids[i], out_ids[j_min]);
 
             if (logits_size > 0) {
                 for (uint32_t k = 0; k < n_vocab; k++) {
-                std::swap(logits[i0*n_vocab + k], logits[i1*n_vocab + k]);
+                    std::swap(logits[i*n_vocab + k], logits[j_min*n_vocab + k]);
                 }
             }
 
             if (embd_size > 0) {
                 for (uint32_t k = 0; k < n_embd; k++) {
-                std::swap(embd[i0*n_embd + k], embd[i1*n_embd + k]);
+                    std::swap(embd[i*n_embd + k], embd[j_min*n_embd + k]);
                 }
             }
         }
 
-    output_swaps.clear();
+        std::fill(output_ids.begin(), output_ids.end(), -1);
+
+        for (uint32_t i = 0; i < n_outputs; ++i) {
+            output_ids[out_ids[i]] = i;
+        }
+
+        out_ids.clear();
+    }
 }
 
 //

src/llama-context.h

@@ -181,6 +181,8 @@ private:
     // Returns max number of outputs for which space was reserved.
     uint32_t output_reserve(int32_t n_outputs);
 
+    // make the outputs have the same order they had in the user-provided batch
+    // mostly relevant when non-simple batch splits are used
     void output_reorder();
 
     //
@@ -252,13 +254,6 @@ private:
 
     std::vector<int32_t> output_ids; // map batch token positions to ids of the logits and embd buffers
 
-    struct swap_info {
-        uint32_t i0;
-        uint32_t i1;
-    };
-
-    std::vector<swap_info> output_swaps;
-
     ggml_backend_sched_ptr sched;
 
     ggml_backend_t backend_cpu = nullptr;