From 6b8cedf3bcd2282e9f31b00026178d6bb393fc3e Mon Sep 17 00:00:00 2001
From: Ed Addario <eaddario@hotmail.com>
Date: Sun, 21 Sep 2025 13:42:31 +0100
Subject: [PATCH] Refactor estimate_lambda()

---
 src/llama-quant.cpp | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/llama-quant.cpp b/src/llama-quant.cpp
index b1302df431..ebacf68806 100644
--- a/src/llama-quant.cpp
+++ b/src/llama-quant.cpp
@@ -975,30 +975,29 @@ static std::unordered_map<std::string, ggml_type> target_bpw_type(
     };
 
     // Returns lambda per slice or 0.0 if no activations
-    auto estimate_lambda = [&](const float * values, const float * activations, const int64_t n_per_row, const int64_t ne2) -> std::vector<float>
-    {
-        std::vector<float> lambdas(std::max<int64_t>(1, ne2), 0.0f);
+    auto estimate_lambda = [&](const float * values, const float * activations, const int64_t n_per_row, const int64_t ne2) -> std::vector<float> {
+        const int64_t ns = std::max<int64_t>(1, ne2);
+        std::vector<float> lambdas(ns, 0.0f);
         if (!activations) { return lambdas; }
 
-        for (int64_t s = 0; s < std::max<int64_t>(1, ne2); ++s) {
+        for (int64_t s = 0; s < ns; ++s) {
             const float * v = values ? values + s * n_per_row : nullptr;
             const float * a = activations + s * n_per_row;
             double s1 = 0.0;
             double s2 = 0.0;
             for (int64_t j = 0; j < n_per_row; ++j) {
                 const double w = v ? std::max(0.0f, v[j]) : 1.0;
-                const double aw = std::sqrt(w) * a[j];
-                const double aw2 = aw * aw;
-                s1 += aw2;
-                s2 += aw2 * aw2;
+                const double aw2 = std::sqrt(w) * a[j];
+                const double z = aw2 * aw2;
+                s1 += z;
+                s2 += z * z;
             }
 
             float l = 0.0f;
             if (s1 > 0.0) {
                 const auto n = (double)n_per_row;
                 const double c = std::max(0.0, s2 / (s1 * s1 + epsilon) - 1.0 / n);
-                double lambda = 8.0 * (c / (c + 1.0));
-                l = (float)std::clamp(lambda, 0.0, 12.0);
+                l = (float) std::clamp(8.0 * (c / (c + 1.0)), 0.0, 12.0);
             }
 
             lambdas[(size_t)s] = l;