COMPMID-1809: Create a neon vector wrapper using register size.

Change-Id: I2657f0c09918924a38a75c395301414e50edc198
Reviewed-on: https://review.mlplatform.org/412
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Giuseppe Rossini <giuseppe.rossini@arm.com>
diff --git a/arm_compute/core/NEON/wrapper/traits.h b/arm_compute/core/NEON/wrapper/traits.h
index 5cd6086..0dbd90d 100644
--- a/arm_compute/core/NEON/wrapper/traits.h
+++ b/arm_compute/core/NEON/wrapper/traits.h
@@ -40,7 +40,7 @@
 /** 128-bit vector tag */
 struct vector_128_tag {};
 
-/** Create the appropriate NEON vector given its type and size */
+/** Create the appropriate NEON vector given its type and size in terms of elements */
 template <typename T, int S> struct neon_vector;
 // Specializations
 #ifndef DOXYGEN_SKIP_THIS
@@ -72,6 +72,46 @@
 template <typename T, int S> using neon_vector_t = typename neon_vector<T, S>::type;
 /**  Helper type template to get the tag type of a neon vector */
 template <typename T, int S> using neon_vector_tag_t = typename neon_vector<T, S>::tag_type;
+
+/** Vector bit-width enum class */
+enum class BitWidth
+{
+    W64,  /**< 64-bit width */
+    W128, /**< 128-bit width */
+};
+
+/** Create the appropriate NEON vector given its type and size in terms of bits */
+template <typename T, BitWidth BW> struct neon_bitvector;
+// Specializations
+#ifndef DOXYGEN_SKIP_THIS
+template <> struct neon_bitvector<uint8_t, BitWidth::W64>{ using type = uint8x8_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<int8_t, BitWidth::W64>{ using type = int8x8_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<uint8_t, BitWidth::W128>{ using type = uint8x16_t; using tag_type = vector_128_tag; };
+template <> struct neon_bitvector<int8_t, BitWidth::W128>{ using type = int8x16_t; using tag_type = vector_128_tag; };
+template <> struct neon_bitvector<uint16_t, BitWidth::W64>{ using type = uint16x4_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<int16_t, BitWidth::W64>{ using type = int16x4_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<uint16_t, BitWidth::W128>{ using type = uint16x8_t; using tag_type = vector_128_tag; };
+template <> struct neon_bitvector<int16_t, BitWidth::W128>{ using type = int16x8_t; using tag_type = vector_128_tag; };
+template <> struct neon_bitvector<uint32_t, BitWidth::W64>{ using type = uint32x2_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<int32_t, BitWidth::W64>{ using type = int32x2_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<uint32_t, BitWidth::W128>{ using type = uint32x4_t; using tag_type = vector_128_tag; };
+template <> struct neon_bitvector<int32_t, BitWidth::W128>{ using type = int32x4_t; using tag_type = vector_128_tag; };
+template <> struct neon_bitvector<uint64_t, BitWidth::W64>{ using type = uint64x1_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<int64_t, BitWidth::W64>{ using type = int64x1_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<uint64_t, BitWidth::W128>{ using type = uint64x2_t; using tag_type = vector_128_tag; };
+template <> struct neon_bitvector<int64_t, BitWidth::W128>{ using type = int64x2_t; using tag_type = vector_128_tag; };
+template <> struct neon_bitvector<float_t, BitWidth::W64>{ using type = float32x2_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<float_t, BitWidth::W128>{ using type = float32x4_t; using tag_type = vector_128_tag; };
+#ifdef __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
+template <> struct neon_bitvector<float16_t, BitWidth::W64>{ using type = float16x4_t; using tag_type = vector_64_tag; };
+template <> struct neon_bitvector<float16_t, BitWidth::W128>{ using type = float16x8_t; using tag_type = vector_128_tag; };
+#endif // __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
+#endif /* DOXYGEN_SKIP_THIS */
+
+/**  Helper type template to get the type of a neon vector */
+template <typename T, BitWidth BW> using neon_bitvector_t = typename neon_bitvector<T, BW>::type;
+/**  Helper type template to get the tag type of a neon vector */
+template <typename T, BitWidth BW> using neon_bitvector_tag_t = typename neon_bitvector<T, BW>::tag_type;
 // clang-format on
 // *INDENT-ON*
 } // namespace traits