exposed exponent_val in dynamic temp sampler

common/sampling.cpp

@@ -130,6 +130,7 @@ static void sampler_queue(
 
     const float         temp              = params.temp;
     const float         dynatemp_range    = params.dynatemp_range;
+    const float         dynatemp_exponent = params.dynatemp_exponent;
     const int32_t       top_k             = params.top_k <= 0 ? n_vocab : params.top_k;
     const float         top_p             = params.top_p;
     const float         min_p             = params.min_p;
@@ -154,7 +155,7 @@ static void sampler_queue(
                     dynatemp_min = dynatemp_min<0?0:dynatemp_min;
                     dynatemp_max = dynatemp_max<0?0:dynatemp_max;
 
-                    llama_sample_entropy(ctx_main, &cur_p, dynatemp_min, dynatemp_max);
+                    llama_sample_entropy(ctx_main, &cur_p, dynatemp_min, dynatemp_max, dynatemp_exponent);
                 }
                 else
                 {

common/sampling.h

@@ -19,6 +19,7 @@ typedef struct llama_sampling_params {
     float       typical_p             = 1.00f;    // 1.0 = disabled
     float       temp                  = 0.80f;    // <= 0.0 to sample greedily, 0.0 to not output probabilities
     float       dynatemp_range        = 0.00f;    // 0.0 = disabled
+    float       dynatemp_exponent     = 1.00f;    // controls how entropy maps to temperature in dynamic temperature sampler
     int32_t     penalty_last_n        = 64;       // last n tokens to penalize (0 = disable penalty, -1 = context size)
     float       penalty_repeat        = 1.10f;    // 1.0 = disabled
     float       penalty_freq          = 0.00f;    // 0.0 = disabled

llama.cpp

@@ -7783,13 +7783,11 @@ void llama_sample_typical(struct llama_context * ctx, llama_token_data_array * c
     }
 }
 
-void llama_sample_entropy(struct llama_context * ctx, llama_token_data_array * candidates_p, float min_temp = 0, float max_temp = 2.0f) {
+void llama_sample_entropy(struct llama_context * ctx, llama_token_data_array * candidates_p, float min_temp, float max_temp, float exponent_val) {
     const int64_t t_start_sample_us = ggml_time_us();
 
     llama_sample_softmax(ctx, candidates_p);
 
-    float exponent_val = 1.0f;
-
     // Calculate entropy of the softmax probabilities
     float entropy = 0.0f;
     for (size_t i = 0; i < candidates_p->size; ++i) {

llama.h

@@ -779,7 +779,8 @@ extern "C" {
             struct llama_context * ctx,
           llama_token_data_array * candidates_p,
                            float   min_temp,
-                           float   max_temp);
+                           float   max_temp,
+                           float   exponent_val);
 
     LLAMA_API void llama_sample_temp(
             struct llama_context * ctx,