有明确的警告：-ffast-math 假定没有 NaN 与无穷，包围盒可能出现这些值时比较结果不可信
进阶案例是视锥体裁剪：理想情况该在 GPU 做，但作为 CPU 端的 SIMD 练习很合适
💡 金句
The issue is that this typically doesn't scale beyond the SSE instruction set. In this post I want to share how you can “transpose” those vectors into lanes to scale your math operations beyond just those typical 4 component XMM registers.