[application] add repetition_penalty to generate func

add some options to 'generate' function of llm

- add naive repetition_penalty option
- add bad_words option

**Self evaluation:**
1. Build test:	 [X]Passed [ ]Failed [ ]Skipped
2. Run test:	 [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: Seungbaek Hong <[email protected]>

Applications/LLaMA/jni/main.cpp

@@ -134,12 +134,53 @@ float applyTKP(float *logits, int len, float temperature, unsigned int top_k,
   return top_indices_and_logits[0].second;
 }
 
-std::vector<int> generate(float *logits, bool do_sample = false,
+/**
+ * @brief Apply repetition penalty to logits
+ */
+void applyRepetitionPenalty(float *logits, unsigned int *input_ids,
+                            unsigned int NUM_INPUT_IDS,
+                            float repetition_penalty = 1) {
+  for (unsigned int i = 0; i < NUM_INPUT_IDS; ++i) {
+    if (logits[input_ids[i]] < 0) {
+      logits[input_ids[i]] *= repetition_penalty;
+    } else {
+      logits[input_ids[i]] /= repetition_penalty;
+    }
+  }
+}
+
+/**
+ * @brief Apply bad words penalty
+ */
+void applyBadWordsPenalty(float *logits, unsigned int *bad_words_ids,
+                          unsigned int NUM_BAD_WORDS_IDS) {
+  for (unsigned int i = 0; i < NUM_BAD_WORDS_IDS; ++i) {
+    logits[bad_words_ids[i]] = -INFINITY;
+  }
+}
+
+std::vector<int> generate(float *logits, unsigned int NUM_VOCAB = 0,
+                          unsigned int NUM_BATCH = 1, bool do_sample = false,
                           float temperature = 1, unsigned int top_k = 1,
-                          float top_p = 0, unsigned int NUM_BATCH = 1,
-                          unsigned int NUM_VOCAB = 96000) {
+                          float top_p = 1, float repetition_penalty = 1,
+                          unsigned int *input_ids = nullptr,
+                          unsigned int NUM_INPUT_IDS = 0,
+                          unsigned int *bad_words_ids = nullptr,
+                          unsigned int NUM_BAD_WORDS_IDS = 0) {
   std::vector<int> outputs;
   for (unsigned int iteration = 0; iteration < NUM_BATCH; ++iteration) {
+
+    // apply repetition penalty
+    if (repetition_penalty != 1 && input_ids != nullptr && NUM_INPUT_IDS != 0) {
+      applyRepetitionPenalty(logits, input_ids, NUM_INPUT_IDS,
+                             repetition_penalty);
+    }
+
+    // apply bad words penalty
+    if (bad_words_ids != nullptr && NUM_BAD_WORDS_IDS != 0) {
+      applyBadWordsPenalty(logits, bad_words_ids, NUM_BAD_WORDS_IDS);
+    }
+
     // return argmax if do_sample is false
     if (do_sample == false) {
       int argmax_idx =
@@ -148,7 +189,6 @@ std::vector<int> generate(float *logits, bool do_sample = false,
     } else {
       // apply temperature & top-k & top-p to logits
       float max_logits = applyTKP(logits, NUM_VOCAB, temperature, top_k, top_p);
-
       // transform logits to softmax
       float sum_exp_logits = 0;
       for (unsigned int i = 0; i < NUM_VOCAB; i++) {
@@ -173,6 +213,7 @@ std::vector<int> generate(float *logits, bool do_sample = false,
 
     // set batch offset
     logits = logits + NUM_VOCAB;
+    input_ids = input_ids + batch_size;
   }
 
   return outputs;
@@ -554,7 +595,7 @@ void run(std::string text, bool apply_temperature) {
   for (unsigned int i = input_len + 1; i < input_len + NUM_TO_GENERATE; ++i) {
     auto output_interval =
       g_model->incremental_inference(1, input, label, MAX_SEQ_LEN, i - 1, i);
-    unsigned int ids = generate(output[0], true, 1, 1, 0, 1, NUM_VOCAB)[0];
+    unsigned int ids = generate(output[0], NUM_VOCAB)[0];
 
     if (i < input_len) {
       input_sample[0] = static_cast<float>(init_input[i]);