mattkretz · mattkretz · Aug 29, 2025 · Aug 29, 2025 · May 19, 2026 · May 19, 2026
diff --git a/.github/workflows/Clang.yml b/.github/workflows/Clang.yml
@@ -25,7 +25,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [16, 17, 20]
+        version: [16, 17, 20, 23]
 
     runs-on: ubuntu-latest
 
@@ -59,7 +59,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [14, 15, 17, 20]
+        version: [15, 17, 20, 23]
 
     runs-on: ubuntu-latest
 

diff --git a/.github/workflows/GCC.yml b/.github/workflows/GCC.yml
@@ -25,7 +25,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [9, 10, 11, 12, 13, 14, 15]
+        version: [10, 11, 12, 13, 14, 15, 16]
 
     runs-on: ubuntu-latest
 

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: LGPL-3.0-or-later
+# SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception
 # Copyright © 2024      GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
 #                       Matthias Kretz <m.kretz@gsi.de>
 # Copyright © 2023      Álvaro Fernández Sánchez

diff --git a/LICENSE b/LICENSE
@@ -163,3 +163,22 @@ whether future versions of the GNU Lesser General Public License shall
 apply, that proxy's public statement of acceptance of any version is
 permanent authorization for you to choose that version for the
 Library.
+
+
+                    LGPL-3.0-linking-exception
+
+  As a special exception to the GNU Lesser General Public License
+version 3 ("LGPL3"), the copyright holders of this Library give you
+permission to convey to a third party a Combined Work that links statically
+or dynamically to this Library without providing any Minimal Corresponding
+Source or Minimal Application Code as set out in section 4d or providing the
+installation information set out in section 4e, provided that you comply with
+the other provisions of LGPL3 and provided that you meet, for the Application
+the terms and conditions of the license(s) which apply to the Application.
+
+  Except as stated in this special exception, the provisions of LGPL3 will
+continue to comply in full to this Library. If you modify this Library, you
+may apply this exception to your version of this Library, but you are not
+obliged to do so. If you do not wish to do so, delete this exception statement
+from your version. This exception does not (and cannot) modify any license
+terms which apply to the Application, with which you must still comply.
diff --git a/LICENSES/LGPL-3.0-linking-exception.txt b/LICENSES/LGPL-3.0-linking-exception.txt
@@ -0,0 +1,16 @@
+As a special exception to the GNU Lesser General Public License version 3
+("LGPL3"), the copyright holders of this Library give you permission to
+convey to a third party a Combined Work that links statically or dynamically
+to this Library without providing any Minimal Corresponding Source or
+Minimal Application Code as set out in 4d or providing the installation
+information set out in section 4e, provided that you comply with the other
+provisions of LGPL3 and provided that you meet, for the Application the
+terms and conditions of the license(s) which apply to the Application.
+
+Except as stated in this special exception, the provisions of LGPL3 will
+continue to comply in full to this Library. If you modify this Library, you
+may apply this exception to your version of this Library, but you are not
+obliged to do so. If you do not wish to do so, delete this exception
+statement from your version. This exception does not (and cannot) modify any
+license terms which apply to the Application, with which you must still
+comply.
diff --git a/latest_std_flag.sh b/latest_std_flag.sh
@@ -3,7 +3,7 @@
 # Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
 #                       Matthias Kretz <m.kretz@gsi.de>
 
-for std in gnu++23 gnu++2b c++23 c++2b gnu++20 gnu++2a c++20 c++2a gnu++17 c++17; do
+for std in gnu++26 c++26 gnu++23 gnu++2b c++23 c++2b gnu++20 gnu++2a c++20 c++2a gnu++17 c++17; do
   if $CXX -x c++ -c -std=$std /dev/null 2>/dev/null; then
     echo $std
     exit

diff --git a/stdlibtest.cpp b/stdlibtest.cpp
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2025      GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/constexpr_wrapper.h b/vir/constexpr_wrapper.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023-2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/detail.h b/vir/detail.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2022–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd.h b/vir/simd.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2022–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_benchmarking.h b/vir/simd_benchmarking.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2019–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_bit.h b/vir/simd_bit.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2022–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_bitset.h b/vir/simd_bitset.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2022–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_cast.h b/vir/simd_cast.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2022–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_concepts.h b/vir/simd_concepts.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_cvt.h b/vir/simd_cvt.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_execution.h b/vir/simd_execution.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_float_ops.h b/vir/simd_float_ops.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2022–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_iota.h b/vir/simd_iota.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_permute.h b/vir/simd_permute.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */
@@ -185,7 +185,7 @@ namespace vir
 
 #if defined __GNUC__
       if (not std::is_constant_evaluated())
-	if constexpr (std::has_single_bit(sizeof(V)) and V::size() <= stdx::native_simd<T>::size())
+	if constexpr (std::has_single_bit(sizeof(V)))// and V::size() <= stdx::native_simd<T>::size())
 	  {
 #if defined __AVX2__
 	    using v4df [[gnu::vector_size(32)]] = double;
@@ -330,6 +330,100 @@ namespace vir
 		 return a[w + j];
       });
     }
+
+  template <vir::any_simd_or_mask V0, std::same_as<V0>... Vs>
+    VIR_ALWAYS_INLINE constexpr stdx::resize_simd_t<V0::size() * (1 + sizeof...(Vs)), V0>
+    simd_interleave(V0 const& v0, Vs const&... vs) noexcept
+    {
+      using T = typename V0::value_type;
+      constexpr unsigned Bytes = sizeof(T) * std::bit_ceil(unsigned(V0::size()));
+      using VBuiltin [[gnu::vector_size(Bytes)]] = T;
+      if constexpr (V0::size() == 4 and sizeof...(Vs) == 1 and std::is_trivially_copyable_v<V0>)
+	{
+	   return [](VBuiltin r0, VBuiltin r1) {
+#if defined __SSE__ and defined __GNUC__
+	     return stdx::concat(V0(__builtin_ia32_unpcklps (r0, r1)),
+				 V0(__builtin_ia32_unpckhps (r0, r1)));
+#else
+	     return stdx::concat(
+		      std::bit_cast<V0>(__builtin_shufflevector(r0, r1, 0, 4, 1, 5)),
+		      std::bit_cast<V0>(__builtin_shufflevector(r0, r1, 2, 6, 3, 7)));
+#endif
+	   }(std::bit_cast<VBuiltin>(v0), std::bit_cast<VBuiltin>(vs)...);
+	}
+#if defined __SSE__ and defined __GNUC__
+      else if constexpr (std::is_floating_point_v<T> and sizeof(T) == sizeof(float)
+			   and V0::size() == 4 and sizeof...(Vs) == 3)
+	 {
+	   return [](VBuiltin r0, VBuiltin r1, VBuiltin r2, VBuiltin r3) {
+	     VBuiltin t0 = __builtin_ia32_unpcklps(r0, r1);
+	     VBuiltin t1 = __builtin_ia32_unpcklps(r2, r3);
+	     VBuiltin t2 = __builtin_ia32_unpckhps(r0, r1);
+	     VBuiltin t3 = __builtin_ia32_unpckhps(r2, r3);
+	     return stdx::concat(std::bit_cast<V0>(__builtin_ia32_movlhps(t0, t1)),
+				 std::bit_cast<V0>(__builtin_ia32_movhlps(t1, t0)),
+				 std::bit_cast<V0>(__builtin_ia32_movlhps(t2, t3)),
+				 std::bit_cast<V0>(__builtin_ia32_movhlps(t3, t2)));
+	   }(std::bit_cast<VBuiltin>(v0), std::bit_cast<VBuiltin>(vs)...);
+	 }
+#endif
+#if defined __SSE2__ and defined __GNUC__ and __has_builtin(__builtin_ia32_punpckldq128)
+      else if constexpr (std::is_integral_v<T> and sizeof(T) == sizeof(int)
+			   and V0::size() == 4 and sizeof...(Vs) == 3)
+	 {
+	   using VInt [[gnu::vector_size(16)]] = int;
+	   return [](VInt r0, VInt r1, VInt r2, VInt r3) {
+	     VInt t0 = __builtin_ia32_punpckldq128(r0, r2);
+	     VInt t1 = __builtin_ia32_punpckldq128(r1, r3);
+	     VInt t2 = __builtin_ia32_punpckhdq128(r0, r2);
+	     VInt t3 = __builtin_ia32_punpckhdq128(r1, r3);
+	     return stdx::concat(std::bit_cast<V0>(__builtin_ia32_punpckldq128(t0, t1)),
+				 std::bit_cast<V0>(__builtin_ia32_punpckhdq128(t0, t1)),
+				 std::bit_cast<V0>(__builtin_ia32_punpckldq128(t2, t3)),
+				 std::bit_cast<V0>(__builtin_ia32_punpckhdq128(t2, t3)));
+	   }(std::bit_cast<VInt>(v0), std::bit_cast<VInt>(vs)...);
+	 }
+#endif
+      else if constexpr (std::is_floating_point_v<T> and sizeof(T) == sizeof(double)
+			   and V0::size() == 4 and sizeof...(Vs) == 3)
+	 {
+#if defined __AVX__ and defined __GNUC__
+	   return [](VBuiltin a, VBuiltin b, VBuiltin c, VBuiltin d) {
+	     VBuiltin t0 = __builtin_ia32_unpcklpd256(a, b); // a0 b0 a2 b2
+	     VBuiltin t1 = __builtin_ia32_unpcklpd256(c, d); // c0 d0 c2 d2
+	     VBuiltin t2 = __builtin_ia32_unpckhpd256(a, b); // a1 b1 a3 b3
+	     VBuiltin t3 = __builtin_ia32_unpckhpd256(c, d); // c1 d1 c3 d3
+	     return stdx::concat(std::bit_cast<V0>(__builtin_ia32_vperm2f128_pd256(t0, t1, 0x20)),
+				 std::bit_cast<V0>(__builtin_ia32_vperm2f128_pd256(t2, t3, 0x20)),
+				 std::bit_cast<V0>(__builtin_ia32_vperm2f128_pd256(t0, t1, 0x31)),
+				 std::bit_cast<V0>(__builtin_ia32_vperm2f128_pd256(t3, t2, 0x31)));
+	   }(std::bit_cast<VBuiltin>(v0), std::bit_cast<VBuiltin>(vs)...);
+#elif defined __SSE2__ and defined __GNUC__ and __has_builtin(__builtin_ia32_unpcklpd)
+	   using v2df [[gnu::vector_size(16)]] = double;
+	   using v4df = v2df[2];
+	   return [](auto a0, auto b0, auto c0, auto d0) {
+	     v4df a, b, c, d;
+	     std::memcpy(&a, &a0, sizeof(v4df));
+	     std::memcpy(&b, &b0, sizeof(v4df));
+	     std::memcpy(&c, &c0, sizeof(v4df));
+	     std::memcpy(&d, &d0, sizeof(v4df));
+	     stdx::fixed_size_simd<T, 16> ret;
+	     v2df tmp[8] = {
+	       __builtin_ia32_unpcklpd(a[0], b[0]), __builtin_ia32_unpcklpd(c[0], d[0]),
+	       __builtin_ia32_unpckhpd(a[0], b[0]), __builtin_ia32_unpckhpd(c[0], d[0]),
+	       __builtin_ia32_unpcklpd(a[1], b[1]), __builtin_ia32_unpcklpd(c[1], d[1]),
+	       __builtin_ia32_unpckhpd(a[1], b[1]), __builtin_ia32_unpckhpd(c[1], d[1])
+	     };
+	     std::memcpy(&detail::internal_data_hack(ret, 0), tmp, sizeof(tmp));
+	     return ret;
+	   }(detail::internal_data_hack(v0, 0), detail::internal_data_hack(vs, 0)...);
+#endif
+	 }
+      return simd_permute(stdx::concat(v0, vs...), [](int i) {
+	       constexpr int N = 1 + sizeof...(vs);
+	       return (i % N) * V0::size() + (i / N);
+	     });
+    }
 }
 
 #endif // has concepts

diff --git a/vir/simd_resize.h b/vir/simd_resize.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2022–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simd_version.h b/vir/simd_version.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2024–2025 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/simdize.h b/vir/simdize.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */

diff --git a/vir/struct_reflect.h b/vir/struct_reflect.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2018–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */
@@ -27,6 +27,19 @@ namespace vir
     using std::size_t;
 
     // struct_size implementation
+#if __cpp_structured_bindings >= 202411L
+
+    template <typename T>
+      requires requires { T{}; }
+      consteval size_t
+      struct_size()
+      {
+	[[maybe_unused]] auto [...pack] = T{};
+	return sizeof...(pack);
+      }
+
+#else
+
     template <typename Struct>
       struct anything_but_base_of
       {
@@ -117,6 +130,8 @@ namespace vir
 	  }
       }
 
+#endif
+
     // struct_get implementation
     template <size_t Total>
       struct struct_get;

diff --git a/vir/test.cpp b/vir/test.cpp
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */
@@ -209,7 +209,7 @@ namespace test_struct_reflect
   static_assert(vir::reflectable_struct<std::array<int, 0>>);
   static_assert(vir::reflectable_struct<std::array<int, 2>>);
   static_assert(vir::reflectable_struct<std::pair<int, short>>);
-  static_assert(not vir::reflectable_struct<std::complex<float>>);
+  static_assert(vir::reflectable_struct<std::complex<float>>);
 
   template <typename T>
     struct A
@@ -248,10 +248,14 @@ static_assert(std::same_as<vir::simdize<void>, void>);
 
 static_assert(std::same_as<vir::simdize<std::tuple<>>, std::tuple<>>);
 
-static_assert(std::same_as<vir::simdize<std::complex<float>>, std::complex<float>>);
+static_assert(std::same_as<vir::simdize<std::complex<float>>,
+			   vir::vectorized_struct<std::complex<float>, V<float>::size()>>);
+
+static_assert(std::is_base_of_v<std::complex<V<float>>, vir::simdize<std::complex<float>>>);
 
 static_assert(std::same_as<vir::simdize<std::tuple<std::complex<float>>>,
-			   std::tuple<std::complex<float>>>);
+			   vir::vectorized_struct<std::tuple<std::complex<float>>,
+						  V<float>::size()>>);
 
 static_assert(std::same_as<vir::simdize<std::tuple<int, double>>,
 			   vir::vectorized_struct<std::tuple<int, double>, V<int>::size()>>);
@@ -388,12 +392,10 @@ static_assert(vir::simdize_size_v<vir::simdize<Point>> == stdx::native_simd<floa
 static_assert(std::same_as<typename vir::simdize<Point>::mask_type,
 			   typename V<float>::mask_type>);
 
-static_assert(not vir::vectorizable_struct<std::complex<float>>);
-static_assert(not vir::vectorizable_struct<std::tuple<std::complex<float>>>);
-static_assert(not vir::vectorizable_struct<std::tuple<std::complex<float>,
-							       std::complex<double>>>);
-static_assert(not vir::vectorizable_struct<std::tuple<int, float, double,
-							       std::complex<double>>>);
+static_assert(vir::vectorizable_struct<std::complex<float>>);
+static_assert(vir::vectorizable_struct<std::tuple<std::complex<float>>>);
+static_assert(vir::vectorizable_struct<std::tuple<std::complex<float>, std::complex<double>>>);
+static_assert(vir::vectorizable_struct<std::tuple<int, float, double, std::complex<double>>>);
 
 void f(typename vir::detail::simdize_template_arguments<Point, 0>::type);
 static_assert(vir::vectorizable_struct_template<Point>);

diff --git a/vir/test_constexpr_wrapper.cpp b/vir/test_constexpr_wrapper.cpp
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception */
 /* Copyright © 2023–2024 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
  *                       Matthias Kretz <m.kretz@gsi.de>
  */