From 2907ee1a90c2a538b3585f56f52b3716ca2cccd5 Mon Sep 17 00:00:00 2001
From: Shawn Xu <xu107288696@gmail.com>
Date: Sun, 1 Mar 2026 14:54:35 -0800
Subject: [PATCH] Requantize smallnet to nn-47fc8b7fff06.nnue

Passed Non-regression STC:
LLR: 3.01 (-2.94,2.94) <-1.75,0.25>
Total: 340384 W: 88165 L: 88274 D: 163945
Ptnml(0-2): 1145, 40248, 87571, 40027, 1201
https://tests.stockfishchess.org/tests/view/69a4c49ab4a714eaaa196bc0

Passed Non-regression LTC:
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 125922 W: 32222 L: 32106 D: 61594
Ptnml(0-2): 100, 13815, 35002, 13957, 87
https://tests.stockfishchess.org/tests/view/69a9d5f489704e42c5e3a35d

closes https://github.com/official-stockfish/Stockfish/pull/6655

Bench: 2171643
---
 src/evaluate.h                      |  2 +-
 src/nnue/nnue_feature_transformer.h | 29 ++++++-----------------------
 2 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/src/evaluate.h b/src/evaluate.h
index d7c162cbe..4af7093e0 100644
--- a/src/evaluate.h
+++ b/src/evaluate.h
@@ -34,7 +34,7 @@ namespace Eval {
 // name of the macro or the location where this macro is defined, as it is used
 // in the Makefile/Fishtest.
 #define EvalFileDefaultNameBig "nn-9a0cc2a62c52.nnue"
-#define EvalFileDefaultNameSmall "nn-37f18f62d772.nnue"
+#define EvalFileDefaultNameSmall "nn-47fc8b7fff06.nnue"
 
 namespace NNUE {
 struct Networks;
diff --git a/src/nnue/nnue_feature_transformer.h b/src/nnue/nnue_feature_transformer.h
index a2cc00022..798c0fa11 100644
--- a/src/nnue/nnue_feature_transformer.h
+++ b/src/nnue/nnue_feature_transformer.h
@@ -155,13 +155,6 @@ class FeatureTransformer {
             permute<8>(threatWeights, InversePackusEpi16Order);
     }
 
-    inline void scale_weights(bool read) {
-        for (auto& w : weights)
-            w = read ? w * 2 : w / 2;
-        for (auto& b : biases)
-            b = read ? b * 2 : b / 2;
-    }
-
     // Read network parameters
     bool read_parameters(std::istream& stream) {
         read_leb_128(stream, biases);
@@ -182,9 +175,6 @@ class FeatureTransformer {
 
         permute_weights();
 
-        if constexpr (!UseThreats)
-            scale_weights(true);
-
         return !stream.fail();
     }
 
@@ -194,9 +184,6 @@ class FeatureTransformer {
 
         copy->unpermute_weights();
 
-        if constexpr (!UseThreats)
-            copy->scale_weights(false);
-
         write_leb_128<BiasType>(stream, copy->biases);
 
         if constexpr (UseThreats)
@@ -288,7 +275,7 @@ class FeatureTransformer {
             constexpr IndexType NumOutputChunks = HalfDimensions / 2 / OutputChunkSize;
 
             const vec_t Zero = vec_zero();
-            const vec_t One  = vec_set_16(UseThreats ? 255 : 127 * 2);
+            const vec_t One  = vec_set_16(255);
 
             const vec_t* in0 = reinterpret_cast<const vec_t*>(&(accumulation[perspectives[p]][0]));
             const vec_t* in1 =
@@ -408,18 +395,14 @@ class FeatureTransformer {
 
                 if constexpr (UseThreats)
                 {
-                    BiasType sum0t = threatAccumulation[static_cast<int>(perspectives[p])][j + 0];
-                    BiasType sum1t =
+                    sum0 += threatAccumulation[static_cast<int>(perspectives[p])][j + 0];
+                    sum1 +=
                       threatAccumulation[static_cast<int>(perspectives[p])][j + HalfDimensions / 2];
-                    sum0 = std::clamp<BiasType>(sum0 + sum0t, 0, 255);
-                    sum1 = std::clamp<BiasType>(sum1 + sum1t, 0, 255);
-                }
-                else
-                {
-                    sum0 = std::clamp<BiasType>(sum0, 0, 127 * 2);
-                    sum1 = std::clamp<BiasType>(sum1, 0, 127 * 2);
                 }
 
+                sum0 = std::clamp<BiasType>(sum0, 0, 255);
+                sum1 = std::clamp<BiasType>(sum1, 0, 255);
+
                 output[offset + j] = static_cast<OutputType>(unsigned(sum0 * sum1) / 512);
             }