avx implementation of transpose for [u]int[8|16]

Author: serge-sans-paille

include/xsimd/arch/xsimd_avx.hpp

@@ -29,6 +29,11 @@ namespace xsimd
         template <class A, class T, size_t I>
         XSIMD_INLINE batch<T, A> insert(batch<T, A> const& self, T val, index<I>, requires_arch<generic>) noexcept;
 
+        template <class A>
+        XSIMD_INLINE void transpose(batch<uint16_t, A>* matrix_begin, batch<uint16_t, A>* matrix_end, requires_arch<generic>) noexcept;
+        template <class A>
+        XSIMD_INLINE void transpose(batch<uint8_t, A>* matrix_begin, batch<uint8_t, A>* matrix_end, requires_arch<generic>) noexcept;
+
         namespace detail
         {
             XSIMD_INLINE void split_avx(__m256i val, __m128i& low, __m128i& high) noexcept
@@ -1676,6 +1681,78 @@ namespace xsimd
             return transpose(reinterpret_cast<batch<double, A>*>(matrix_begin), reinterpret_cast<batch<double, A>*>(matrix_end), A {});
         }
 
+        template <class A>
+        XSIMD_INLINE void transpose(batch<uint16_t, A>* matrix_begin, batch<uint16_t, A>* matrix_end, requires_arch<avx>) noexcept
+        {
+            assert((matrix_end - matrix_begin == batch<uint16_t, A>::size) && "correctly sized matrix");
+            (void)matrix_end;
+            batch<uint16_t, sse4_2> tmp_lo0[8];
+            for (int i = 0; i < 8; ++i)
+                tmp_lo0[i] = _mm256_castsi256_si128(matrix_begin[i]);
+            transpose(tmp_lo0 + 0, tmp_lo0 + 8, sse4_2 {});
+
+            batch<uint16_t, sse4_2> tmp_hi0[8];
+            for (int i = 0; i < 8; ++i)
+                tmp_hi0[i] = _mm256_castsi256_si128(matrix_begin[8 + i]);
+            transpose(tmp_hi0 + 0, tmp_hi0 + 8, sse4_2 {});
+
+            batch<uint16_t, sse4_2> tmp_lo1[8];
+            for (int i = 0; i < 8; ++i)
+                tmp_lo1[i] = _mm256_extractf128_si256(matrix_begin[i], 1);
+            transpose(tmp_lo1 + 0, tmp_lo1 + 8, sse4_2 {});
+
+            batch<uint16_t, sse4_2> tmp_hi1[8];
+            for (int i = 0; i < 8; ++i)
+                tmp_hi1[i] = _mm256_extractf128_si256(matrix_begin[8 + i], 1);
+            transpose(tmp_hi1 + 0, tmp_hi1 + 8, sse4_2 {});
+
+            for (int i = 0; i < 8; ++i)
+                matrix_begin[i] = detail::merge_sse(tmp_lo0[i], tmp_hi0[i]);
+            for (int i = 0; i < 8; ++i)
+                matrix_begin[i + 8] = detail::merge_sse(tmp_lo1[i], tmp_hi1[i]);
+        }
+        template <class A>
+        XSIMD_INLINE void transpose(batch<int16_t, A>* matrix_begin, batch<int16_t, A>* matrix_end, requires_arch<avx>) noexcept
+        {
+            return transpose(reinterpret_cast<batch<uint16_t, A>*>(matrix_begin), reinterpret_cast<batch<uint16_t, A>*>(matrix_end), A {});
+        }
+
+        template <class A>
+        XSIMD_INLINE void transpose(batch<uint8_t, A>* matrix_begin, batch<uint8_t, A>* matrix_end, requires_arch<avx>) noexcept
+        {
+            assert((matrix_end - matrix_begin == batch<uint8_t, A>::size) && "correctly sized matrix");
+            (void)matrix_end;
+            batch<uint8_t, sse4_2> tmp_lo0[16];
+            for (int i = 0; i < 16; ++i)
+                tmp_lo0[i] = _mm256_castsi256_si128(matrix_begin[i]);
+            transpose(tmp_lo0 + 0, tmp_lo0 + 16, sse4_2 {});
+
+            batch<uint8_t, sse4_2> tmp_hi0[16];
+            for (int i = 0; i < 16; ++i)
+                tmp_hi0[i] = _mm256_castsi256_si128(matrix_begin[16 + i]);
+            transpose(tmp_hi0 + 0, tmp_hi0 + 16, sse4_2 {});
+
+            batch<uint8_t, sse4_2> tmp_lo1[16];
+            for (int i = 0; i < 16; ++i)
+                tmp_lo1[i] = _mm256_extractf128_si256(matrix_begin[i], 1);
+            transpose(tmp_lo1 + 0, tmp_lo1 + 16, sse4_2 {});
+
+            batch<uint8_t, sse4_2> tmp_hi1[16];
+            for (int i = 0; i < 16; ++i)
+                tmp_hi1[i] = _mm256_extractf128_si256(matrix_begin[16 + i], 1);
+            transpose(tmp_hi1 + 0, tmp_hi1 + 16, sse4_2 {});
+
+            for (int i = 0; i < 16; ++i)
+                matrix_begin[i] = detail::merge_sse(tmp_lo0[i], tmp_hi0[i]);
+            for (int i = 0; i < 16; ++i)
+                matrix_begin[i + 16] = detail::merge_sse(tmp_lo1[i], tmp_hi1[i]);
+        }
+        template <class A>
+        XSIMD_INLINE void transpose(batch<int8_t, A>* matrix_begin, batch<int8_t, A>* matrix_end, requires_arch<avx>) noexcept
+        {
+            return transpose(reinterpret_cast<batch<uint8_t, A>*>(matrix_begin), reinterpret_cast<batch<uint8_t, A>*>(matrix_end), A {});
+        }
+
         // trunc
         template <class A>
         XSIMD_INLINE batch<float, A> trunc(batch<float, A> const& self, requires_arch<avx>) noexcept