chore: import upstream snapshot with attribution

source/core/MNNMemoryUtils.cpp

@@ -0,0 +1,62 @@
+//
+//  MNNMemoryUtils.cpp
+//  MNN
+//
+//  Created by MNN on 2018/07/14.
+//  Copyright © 2018, Alibaba Group Holding Limited
+//
+
+#include "core/MNNMemoryUtils.h"
+#include <stdint.h>
+#include <stdlib.h>
+#include "core/Macro.h"
+//#define MNN_DEBUG_MEMORY
+static inline void **alignPointer(void **ptr, size_t alignment) {
+    return (void **)((intptr_t)((unsigned char *)ptr + alignment - 1) & -alignment);
+}
+
+extern "C" void *MNNMemoryAllocAlign(size_t size, size_t alignment) {
+    MNN_ASSERT(size > 0);
+
+#ifdef MNN_DEBUG_MEMORY
+    return malloc(size);
+#else
+    void **origin = (void **)malloc(size + sizeof(void *) + alignment);
+    MNN_ASSERT(origin != NULL);
+    if (!origin) {
+        return NULL;
+    }
+
+    void **aligned = alignPointer(origin + 1, alignment);
+    aligned[-1]    = origin;
+    return aligned;
+#endif
+}
+
+extern "C" void *MNNMemoryCallocAlign(size_t size, size_t alignment) {
+    MNN_ASSERT(size > 0);
+
+#ifdef MNN_DEBUG_MEMORY
+    return calloc(size, 1);
+#else
+    void **origin = (void **)calloc(size + sizeof(void *) + alignment, 1);
+    MNN_ASSERT(origin != NULL)
+    if (!origin) {
+        return NULL;
+    }
+    void **aligned = alignPointer(origin + 1, alignment);
+    aligned[-1]    = origin;
+    return aligned;
+#endif
+}
+
+extern "C" void MNNMemoryFreeAlign(void *aligned) {
+#ifdef MNN_DEBUG_MEMORY
+    free(aligned);
+#else
+    if (aligned) {
+        void *origin = ((void **)aligned)[-1];
+        free(origin);
+    }
+#endif
+}