X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fnnue%2Fnnue_common.h;fp=src%2Fnnue%2Fnnue_common.h;h=61f18aeec848be9b25edde2b68733e97c8cf254b;hp=eab7d258816cfe4dc2489a43d5c27b098b676d76;hb=72dc7a5c54554a8c7c4bf68aa7de2d4de05f3294;hpb=8cf43c6317665295eece747ed1589ee33a435d2c

diff --git a/src/nnue/nnue_common.h b/src/nnue/nnue_common.h
index eab7d258..61f18aee 100644
--- a/src/nnue/nnue_common.h
+++ b/src/nnue/nnue_common.h
@@ -21,6 +21,9 @@
 #ifndef NNUE_COMMON_H_INCLUDED
 #define NNUE_COMMON_H_INCLUDED
 
+#include <cstring>
+#include <iostream>
+
 #if defined(USE_AVX2)
 #include <immintrin.h>
 
@@ -101,6 +104,22 @@ namespace Eval::NNUE {
     return (n + base - 1) / base * base;
   }
 
+  // Read a signed or unsigned integer from  a stream in little-endian order
+  template <typename IntType>
+  inline IntType read_le(std::istream& stream) {
+    // Read the relevant bytes from the stream in little-endian order
+    std::uint8_t u[sizeof(IntType)];
+    stream.read(reinterpret_cast<char*>(u), sizeof(IntType));
+    // Use unsigned arithmetic to convert to machine order
+    typename std::make_unsigned<IntType>::type v = 0;
+    for (std::size_t i = 0; i < sizeof(IntType); ++i)
+      v = (v << 8) | u[sizeof(IntType) - i - 1];
+    // Copy the machine-ordered bytes into a potentially signed value
+    IntType w;
+    std::memcpy(&w, &v, sizeof(IntType));
+    return w;
+  }
+
 }  // namespace Eval::NNUE
 
 #endif // #ifndef NNUE_COMMON_H_INCLUDED