diff --git a/gpttype_adapter.cpp b/gpttype_adapter.cpp
index 5533a7c55..e7b3135f2 100644
--- a/gpttype_adapter.cpp
+++ b/gpttype_adapter.cpp
@@ -1321,33 +1321,24 @@ void sample_tail_free(llama_token_data_array * cur_p, float z, size_t min_keep)
     sample_softmax(cur_p);
 
     // Compute the first and second derivatives
-    std::vector<float> first_derivatives(cur_p->size - 1);
     std::vector<float> second_derivatives(cur_p->size - 2);
+    float second_derivatives_sum = 0.0f;
 
-    for (size_t i = 0; i < first_derivatives.size(); ++i) {
-        first_derivatives[i] = cur_p->data[i].p - cur_p->data[i + 1].p;
-    }
     for (size_t i = 0; i < second_derivatives.size(); ++i) {
-        second_derivatives[i] = first_derivatives[i] - first_derivatives[i + 1];
-    }
-
-    // Calculate absolute value of second derivatives
-    for (size_t i = 0; i < second_derivatives.size(); ++i) {
-        second_derivatives[i] = std::abs(second_derivatives[i]);
+        float first_derivatives_1 = cur_p->data[i].p - cur_p->data[i + 1].p;
+        float first_derivatives_2 = cur_p->data[i + 1].p - cur_p->data[i + 2].p;
+        second_derivatives[i] = std::abs(first_derivatives_1 - first_derivatives_2);
+        second_derivatives_sum += second_derivatives[i];
     }
 
     // Normalize the second derivatives
-    {
-        const float second_derivatives_sum = std::accumulate(second_derivatives.begin(), second_derivatives.end(), 0.0f);
-
-        if (second_derivatives_sum > 1e-6f) {
-            for (float & value : second_derivatives) {
-                value /= second_derivatives_sum;
-            }
-        } else {
-            for (float & value : second_derivatives) {
-                value = 1.0f / second_derivatives.size();
-            }
+    if (second_derivatives_sum > 1e-6f) {
+        for (float & value : second_derivatives) {
+            value /= second_derivatives_sum;
+        }
+    } else {
+        for (float & value : second_derivatives) {
+            value = 1.0f / second_derivatives.size();
         }
     }