From 4cf3e897054995bf626b7ebf8d6c5079a73c740b Mon Sep 17 00:00:00 2001
From: JCRaymond <jcraymond@github.com>
Date: Sat, 7 Dec 2019 13:49:57 -0500
Subject: [PATCH] Add aligned_allocator

---
 cpu-opt/aligned_allocator.cpp | 62 +++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 cpu-opt/aligned_allocator.cpp

diff --git a/cpu-opt/aligned_allocator.cpp b/cpu-opt/aligned_allocator.cpp
new file mode 100644
index 0000000..84488c6
--- /dev/null
+++ b/cpu-opt/aligned_allocator.cpp
@@ -0,0 +1,62 @@
+#include <immintrin.h>
+#include <memory>
+
+template <class T, int N>
+class aligned_allocator
+{
+
+public:
+
+    typedef T value_type;
+    typedef T& reference;
+    typedef const T& const_reference;
+    typedef T* pointer;
+    typedef const T* const_pointer;
+    typedef size_t size_type;
+    typedef ptrdiff_t difference_type;
+
+    template <class U>
+        struct rebind
+        {
+            typedef aligned_allocator<U,N> other;
+        };
+
+    inline aligned_allocator() throw() {}
+    inline aligned_allocator(const aligned_allocator&) throw() {}
+
+    template <class U>
+        inline aligned_allocator(const aligned_allocator<U,N>&) throw() {}
+
+    inline ~aligned_allocator() throw() {}
+
+    inline pointer address(reference r) { return &r; }
+    inline const_pointer address(const_reference r) const { return &r; }
+
+    pointer allocate(size_type n, typename std::allocator<void>::const_pointer hint = 0);
+    inline void deallocate(pointer p, size_type);
+
+    inline void construct(pointer p, const_reference value) { new (p) value_type(value); }
+    inline void destroy(pointer p) { p->~value_type(); }
+
+    inline size_type max_size() const throw() { return size_type(-1) / sizeof(T); }
+
+    inline bool operator==(const aligned_allocator&) { return true; }
+    inline bool operator!=(const aligned_allocator& rhs) { return !operator==(rhs); }
+};
+
+
+template <class T, int N>
+typename aligned_allocator<T,N>::pointer
+aligned_allocator<T,N>::allocate(size_type n, typename std::allocator<void>::const_pointer) {
+    size_type alloc_size = ((sizeof(T)*(n-1))/N + 1)*N;
+    pointer res = reinterpret_cast<pointer>(_mm_malloc(alloc_size, N));
+    if (res == 0)
+        throw std::bad_alloc();
+    return res;
+}
+
+template <class T, int N>
+void
+aligned_allocator<T,N>::deallocate(pointer p, size_type) {
+    _mm_free(p);
+}