llama : dynamic temperature sampling (#4972)

* implemented dynamic temperature sampling from koboldcpp

* removed trailing whitespace

* removed unused temp parameter in llama_sample_entropy

* exposed exponent_val in dynamic temp sampler

* added debug check for printf statements

* use nullptr in llama_sample_softmax call during llama_sample_entropy

this avoids counting the time taken stats twice

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

* return earlier if there is only 1 candiate (i.e. max_entropy == 0)

* reformat 't' case in llama_sample_queue

Co-authored-by: Jared Van Bortel <cebtenzzre@gmail.com>

* check for one or zero candidates case in llama_sample_entropy

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
Co-authored-by: Jared Van Bortel <cebtenzzre@gmail.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/common/sampling.cpp b/common/sampling.cpp
index dd1ffeb1..efd7eab6 100644
--- a/common/sampling.cpp
+++ b/common/sampling.cpp
@@ -129,6 +129,8 @@ static void sampler_queue(
     const int n_vocab = llama_n_vocab(llama_get_model(ctx_main));
 
     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;
@@ -143,7 +145,15 @@ static void sampler_queue(
             case 'y': llama_sample_typical  (ctx_main, &cur_p, typical_p, min_keep); break;
             case 'p': llama_sample_top_p    (ctx_main, &cur_p, top_p,     min_keep); break;
             case 'm': llama_sample_min_p    (ctx_main, &cur_p, min_p,     min_keep); break;
-            case 't': llama_sample_temp     (ctx_main, &cur_p, temp); break;
+            case 't':
+                if (dynatemp_range > 0) {
+                    float dynatemp_min = std::max(0.0f, temp - dynatemp_range);
+                    float dynatemp_max = std::max(0.0f, temp + dynatemp_range);
+                    llama_sample_entropy(ctx_main, &cur_p, dynatemp_min, dynatemp_max, dynatemp_exponent);
+                } else {
+                    llama_sample_temp(ctx_main, &cur_p, temp);
+                }
+                break;
             default : break;
         }
     }