Some avx512 bugfixes

Fixes #850

Author: cyb70289

include/xsimd/arch/generic/xsimd_generic_memory.hpp

@@ -34,7 +34,7 @@ namespace xsimd
         inline batch<T, A> extract_pair(batch<T, A> const& self, batch<T, A> const& other, std::size_t i, requires_arch<generic>) noexcept
         {
             constexpr std::size_t size = batch<T, A>::size;
-            assert(0 <= i && i < size && "index in bounds");
+            assert(i < size && "index in bounds");
 
             alignas(A::alignment()) T self_buffer[size];
             self.store_aligned(self_buffer);

include/xsimd/arch/xsimd_avx512bw.hpp

@@ -362,11 +362,11 @@ namespace xsimd
         {
             XSIMD_IF_CONSTEXPR(sizeof(T) == 1)
             {
-                return _mm512_mask_blend_epi8(cond, false_br, true_br);
+                return _mm512_mask_blend_epi8(cond, false_br.data, true_br.data);
             }
             else XSIMD_IF_CONSTEXPR(sizeof(T) == 2)
             {
-                return _mm512_mask_blend_epi16(cond, false_br, true_br);
+                return _mm512_mask_blend_epi16(cond, false_br.data, true_br.data);
             }
             else
             {
@@ -410,14 +410,14 @@ namespace xsimd
             batch<T, A> xx;
             if (N & 1)
             {
-                alignas(32) uint64_t buffer[8];
+                alignas(A::alignment()) uint64_t buffer[8];
                 _mm512_store_epi64(&buffer[0], x);
                 for (int i = 7; i > 0; --i)
                     buffer[i] = (buffer[i] << 8) | (buffer[i - 1] >> 56);
                 buffer[0] = buffer[0] << 8;
                 xx = _mm512_load_epi64(&buffer[0]);
 
-                alignas(32) auto slide_perm = detail::make_slide_perm_hi(::xsimd::detail::make_index_sequence<512 / 64>());
+                alignas(A::alignment()) auto slide_perm = detail::make_slide_perm_hi(::xsimd::detail::make_index_sequence<512 / 64>());
                 __m512i xl = _mm512_slli_epi64(x, 8);
                 __m512i xr = _mm512_srli_epi64(x, 56);
                 xr = _mm512_permutex2var_epi64(xr, _mm512_load_epi64(slide_perm.data()), _mm512_setzero_si512());
@@ -429,8 +429,8 @@ namespace xsimd
             {
                 xx = x;
             }
-            alignas(32) auto slide_pattern = detail::make_slide_left_pattern<N / 2>(::xsimd::detail::make_index_sequence<512 / 16>());
-            alignas(32) auto slide_mask = detail::make_slide_left_mask<N / 2>(::xsimd::detail::make_index_sequence<512 / 16>());
+            alignas(A::alignment()) auto slide_pattern = detail::make_slide_left_pattern<N / 2>(::xsimd::detail::make_index_sequence<512 / 16>());
+            alignas(A::alignment()) auto slide_mask = detail::make_slide_left_mask<N / 2>(::xsimd::detail::make_index_sequence<512 / 16>());
             return _mm512_and_si512(_mm512_permutexvar_epi16(_mm512_load_epi32(slide_pattern.data()), xx), _mm512_load_epi32(slide_mask.data()));
         }
 
@@ -469,7 +469,7 @@ namespace xsimd
             batch<T, A> xx;
             if (N & 1)
             {
-                alignas(32) auto slide_perm = detail::make_slide_perm_low(::xsimd::detail::make_index_sequence<512 / 64>());
+                alignas(A::alignment()) auto slide_perm = detail::make_slide_perm_low(::xsimd::detail::make_index_sequence<512 / 64>());
                 __m512i xr = _mm512_srli_epi64(x, 8);
                 __m512i xl = _mm512_slli_epi64(x, 56);
                 xl = _mm512_permutex2var_epi64(xl, _mm512_load_epi64(slide_perm.data()), _mm512_setzero_si512());
@@ -481,8 +481,8 @@ namespace xsimd
             {
                 xx = x;
             }
-            alignas(32) auto slide_pattern = detail::make_slide_right_pattern<N / 2>(::xsimd::detail::make_index_sequence<512 / 16>());
-            alignas(32) auto slide_mask = detail::make_slide_right_mask<N / 2>(::xsimd::detail::make_index_sequence<512 / 16>());
+            alignas(A::alignment()) auto slide_pattern = detail::make_slide_right_pattern<N / 2>(::xsimd::detail::make_index_sequence<512 / 16>());
+            alignas(A::alignment()) auto slide_mask = detail::make_slide_right_mask<N / 2>(::xsimd::detail::make_index_sequence<512 / 16>());
             return _mm512_and_si512(_mm512_permutexvar_epi16(_mm512_load_epi32(slide_pattern.data()), xx), _mm512_load_epi32(slide_mask.data()));
         }
 

include/xsimd/arch/xsimd_avx512f.hpp

@@ -1380,18 +1380,16 @@ namespace xsimd
 
         // scatter
         template <class A, class T,
-                  typename std::enable_if<std::is_same<uint32_t, T>::value || std::is_same<int32_t, T>::value,
-                                          void>::type>
+                  class = typename std::enable_if<std::is_same<uint32_t, T>::value || std::is_same<int32_t, T>::value, void>::type>
         inline void scatter(batch<T, A> const& src, T* dst,
                             batch<int32_t, A> const& index,
                             kernel::requires_arch<avx512f>) noexcept
         {
             _mm512_i32scatter_epi32(dst, index, src, sizeof(T));
         }
 
-        template <class T, class A,
-                  typename std::enable_if<std::is_same<uint64_t, T>::value || std::is_same<int64_t, T>::value,
-                                          void>::type>
+        template <class A, class T,
+                  class = typename std::enable_if<std::is_same<uint64_t, T>::value || std::is_same<int64_t, T>::value, void>::type>
         inline void scatter(batch<T, A> const& src, T* dst,
                             batch<int64_t, A> const& index,
                             kernel::requires_arch<avx512f>) noexcept