[NNUE] Wrap aligned_alloc

For some systems std::aligned_alloc is not available even if c++17 is specified.
Wrap the function and use specific solutions.

Update macosx-version-min to the required minimum.

No functional change.

src/Makefile

@@ -363,8 +363,8 @@ endif
 endif
 
 ifeq ($(KERNEL),Darwin)
-	CXXFLAGS += -arch $(arch) -mmacosx-version-min=10.9
-	LDFLAGS += -arch $(arch) -mmacosx-version-min=10.9
+	CXXFLAGS += -arch $(arch) -mmacosx-version-min=10.15
+	LDFLAGS += -arch $(arch) -mmacosx-version-min=10.15
 endif
 
 ### Travis CI script uses COMPILER to overwrite CXX

src/misc.cpp

@@ -46,6 +46,7 @@ typedef bool(*fun3_t)(HANDLE, CONST GROUP_AFFINITY*, PGROUP_AFFINITY);
 #include <iostream>
 #include <sstream>
 #include <vector>
+#include <cstdlib>
 
 #if defined(__linux__) && !defined(__ANDROID__)
 #include <stdlib.h>
@@ -293,6 +294,29 @@ void prefetch(void* addr) {
 
 #endif
 
+/// Wrappers for systems where the c++17 implementation doesn't guarantee the availability of aligned_alloc.
+/// Memory allocated with std_aligned_alloc must be freed with std_aligned_free.
+///
+
+void* std_aligned_alloc(size_t alignment, size_t size) {
+#if defined(__APPLE__)
+  return aligned_alloc(alignment, size);
+#elif defined(_MSC_VER)
+  return _aligned_alloc(size, alignment);
+#else
+  return std::aligned_alloc(alignment, size);
+#endif
+}
+
+void std_aligned_free(void* ptr) {
+#if defined(__APPLE__)
+  free(ptr);
+#elif defined(_MSC_VER)
+  _aligned_free(ptr);
+#else
+  free(ptr);
+#endif
+}
 
 /// aligned_ttmem_alloc() will return suitably aligned memory, and if possible use large pages.
 /// The returned pointer is the aligned one, while the mem argument is the one that needs

src/misc.h

@@ -33,6 +33,8 @@ const std::string engine_info(bool to_uci = false);
 const std::string compiler_info();
 void prefetch(void* addr);
 void start_logger(const std::string& fname);
+void* std_aligned_alloc(size_t alignment, size_t size);
+void std_aligned_free(void* ptr);
 void* aligned_ttmem_alloc(size_t size, void*& mem);
 void aligned_ttmem_free(void* mem); // nop if mem == nullptr
 

src/nnue/evaluate_nnue.cpp

@@ -57,7 +57,7 @@ namespace Eval::NNUE {
   template <typename T>
   void Initialize(AlignedPtr<T>& pointer) {
 
-    pointer.reset(reinterpret_cast<T*>(std::aligned_alloc(alignof(T), sizeof(T))));
+    pointer.reset(reinterpret_cast<T*>(std_aligned_alloc(alignof(T), sizeof(T))));
     std::memset(pointer.get(), 0, sizeof(T));
   }
 

src/nnue/evaluate_nnue.h

@@ -5,6 +5,7 @@
 
 #include "nnue_feature_transformer.h"
 #include "nnue_architecture.h"
+#include "../misc.h"
 
 #include <memory>
 
@@ -19,7 +20,7 @@ namespace Eval::NNUE {
   struct AlignedDeleter {
     void operator()(T* ptr) const {
       ptr->~T();
-      std::free(ptr);
+      std_aligned_free(ptr);
     }
   };