From bc5c6727f49251771be6ac4aa402d9c4430cb8c0 Mon Sep 17 00:00:00 2001
From: sharkautarch <128002472+sharkautarch@users.noreply.github.com>
Date: Thu, 12 Sep 2024 11:30:57 -0400
Subject: [PATCH] simd constexpr vec: fix errors when building w/ gcc

---
 glm/detail/simd_constexpr/simd_helpers.inl | 19 +++++++++++++++----
 glm/detail/simd_constexpr/vec.hpp          | 20 +++++++++++---------
 2 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/glm/detail/simd_constexpr/simd_helpers.inl b/glm/detail/simd_constexpr/simd_helpers.inl
index eb2a2710..083d64b7 100644
--- a/glm/detail/simd_constexpr/simd_helpers.inl
+++ b/glm/detail/simd_constexpr/simd_helpers.inl
@@ -12,10 +12,21 @@ namespace glm::detail
 		using PaddedVec = PaddedGccVec<Lx, Tx, Qx, detail::BVecNeedsPadding<Lx, Tx, Qx>()>;
 		using gcc_vec_t = PaddedVec<L, T, Q>::GccV;
 		using data_t = typename detail::storage<L, T, detail::is_aligned<Q>::value>::type;
+		
+		static inline auto gcc_vec_to_data(PaddedVec<L, T, Q> v) {
+			if constexpr (L == 3 && !BIsAlignedQ<Q>()) {
+				data_t d;
+				std::memcpy(&d, &v, sizeof(d));
+				return d;
+			} else {
+				return std::bit_cast<data_t>(v);
+			}
+		}
+		
 		static inline auto simd_ctor_scalar(arithmetic auto scalar) {
 			PaddedVec<L, T, Q> v = {};
 			v.gcc_vec = v.gcc_vec + ( (T)scalar );
-			return std::bit_cast<data_t>(v);
+			return gcc_vec_to_data(v);
 		}
 		
 		template <length_t Lx, typename Tx, qualifier Qx> requires (Lx == L)
@@ -24,7 +35,7 @@ namespace glm::detail
 			using OtherPaddedVec = PaddedVec<Lx, Tx, Qx>;
 			OtherPaddedVec o = std::bit_cast<OtherPaddedVec>(v.data);
 			PaddedVec<L, T, Q> converted = {.gcc_vec=__builtin_convertvector(o.gcc_vec, gcc_vec_t)};
-			return std::bit_cast<data_t>(converted);
+			return gcc_vec_to_data(converted);
 		}
 		
 		template <length_t Lx, typename Tx, qualifier Qx> requires (Lx != L && Lx < L)
@@ -39,7 +50,7 @@ namespace glm::detail
 			}
 			
 			PaddedVec<L, T, Q> converted = {.gcc_vec=__builtin_convertvector(oExpanded.gcc_vec, gcc_vec_t)};
-			return std::bit_cast<data_t>(converted);
+			return gcc_vec_to_data(converted);
 		}
 		
 		template<arithmetic... A>
@@ -54,7 +65,7 @@ namespace glm::detail
 			using OtherPaddedVec = PaddedVec<L, typename GetFirstType<A...>::FirstTx, Q>;
 			OtherPaddedVec o = {.gcc_vec={scalars...}};
 			PaddedVec<L, T, Q> converted = {.gcc_vec=__builtin_convertvector(o.gcc_vec, gcc_vec_t)};
-			return std::bit_cast<data_t>(converted);
+			return gcc_vec_to_data(converted);
 		}
 	};
 }
\ No newline at end of file
diff --git a/glm/detail/simd_constexpr/vec.hpp b/glm/detail/simd_constexpr/vec.hpp
index 2cde999b..27bc45fc 100644
--- a/glm/detail/simd_constexpr/vec.hpp
+++ b/glm/detail/simd_constexpr/vec.hpp
@@ -12,6 +12,7 @@
 #include <cstddef>
 #include <array>
 #include <variant>
+#include <cstring>
 namespace glm
 {
 	template <qualifier Q>
@@ -37,35 +38,36 @@ namespace glm
 	namespace detail
 	{
 		template <length_t L, typename T, qualifier Q>
-		using ArrT = T[L];
+		using _ArrT = T[L];
 
 		template <length_t L, typename T, qualifier Q>
 		using _data_t = typename detail::storage<L, T, detail::is_aligned<Q>::value>::type;
 		
 		template <length_t L, typename T, qualifier Q>
-		using GccV = T __attribute__(( vector_size(sizeof(T)*L), aligned(alignof(_data_t<L, T, Q>)) ));
-		
+		struct GccVExt {
+			typedef T GccV __attribute__(( vector_size(sizeof(T)*L), aligned(alignof(_data_t<L, T, Q>)) ));
+		};
 		template <length_t L, typename T, qualifier Q>
 		consteval bool BDataNeedsPadding() {
-			return sizeof(_data_t<L,T,Q>) > sizeof(ArrT<L,T,Q>);
+			return sizeof(_data_t<L,T,Q>) > sizeof(_ArrT<L,T,Q>);
 		}
 		template <length_t L, typename T, qualifier Q>
 		consteval bool BVecNeedsPadding() {
-			return sizeof(_data_t<L,T,Q>) > sizeof(GccV<L,T,Q>);
+			return sizeof(_data_t<L,T,Q>) > sizeof(typename GccVExt<L,T,Q>::GccV);
 		}
 		template <length_t L, typename T, qualifier Q, bool NeedsPadding>
 		struct VecDataArray;
 			
 		template <length_t L, typename T, qualifier Q>
 		struct VecDataArray<L, T, Q, true> {
-			using ArrT = ArrT<L, T, Q>;
+			using ArrT = _ArrT<L, T, Q>;
 			using data_t = _data_t<L,T,Q>;
 			ArrT p;
 			std::byte padding[sizeof(data_t) - sizeof(ArrT)];
 		};
 		template <length_t L, typename T, qualifier Q>
 		struct VecDataArray<L, T, Q, false> {
-			using ArrT = ArrT<L, T, Q>;
+			using ArrT = _ArrT<L, T, Q>;
 			ArrT p;
 		};
 		
@@ -74,7 +76,7 @@ namespace glm
 		
 		template <length_t L, typename T, qualifier Q>
 		struct PaddedGccVec<L, T, Q, true> {
-			using GccV = GccV<L, T,Q>;
+			using GccV = typename GccVExt<L, T,Q>::GccV;
 			using data_t = _data_t<L, T, Q>;
 			GccV gcc_vec;
 			std::byte padding[sizeof(data_t) - sizeof(GccV)];
@@ -82,7 +84,7 @@ namespace glm
 	
 		template <length_t L, typename T, qualifier Q>
 		struct PaddedGccVec<L, T, Q, false> {
-			using GccV = GccV<L, T,Q>;
+			using GccV = typename GccVExt<L, T,Q>::GccV;
 			GccV gcc_vec;
 		};
 	}