src/common/vector_math.h

@@ -1,9 +1,16 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: 2014 Tony Wasserka
 // SPDX-FileCopyrightText: 2014 Dolphin Emulator Project
 // SPDX-License-Identifier: BSD-3-Clause AND GPL-2.0-or-later
 
 #pragma once
 
+#ifdef __ARM_NEON
+#include <arm_neon.h>
+#endif
+
 #include <cmath>
 #include <type_traits>
 
@@ -641,6 +648,23 @@ template <typename T>
     return a.x * b.x + a.y * b.y + a.z * b.z + a.w * b.w;
 }
 
+template <>
+[[nodiscard]] inline float Dot(const Vec4<float>& a, const Vec4<float>& b) {
+#ifdef __ARM_NEON
+    float32x4_t va = vld1q_f32(&a.x);
+    float32x4_t vb = vld1q_f32(&b.x);
+    float32x4_t result = vmulq_f32(va, vb);
+#if defined(__aarch64__) // Use vaddvq_f32 in ARMv8 architectures
+    return vaddvq_f32(result);
+#else // Use manual addition for older architectures
+    float32x2_t sum2 = vadd_f32(vget_high_f32(result), vget_low_f32(result));
+    return vget_lane_f32(vpadd_f32(sum2, sum2), 0);
+#endif
+#else
+    return a.x * b.x + a.y * b.y + a.z * b.z + a.w * b.w;
+#endif
+}
+
 template <typename T>
 [[nodiscard]] constexpr Vec3<decltype(T{} * T{} - T{} * T{})> Cross(const Vec3<T>& a,
                                                                     const Vec3<T>& b) {