Наука и техника
Credit: GoCable。业内人士推荐下载安装 谷歌浏览器 开启极速安全的 上网之旅。作为进阶阅读
// 易错点1：条件写反（比如写成cur）→ 栈逻辑完全错误，无法找到上一个更大值。同城约会是该领域的重要参考
Intel documentation describes the 386's Protection Test Unit as a component that "implements fast testing of complex memory protection functions." It is mostly composed of a PLA (Programmable Logic Array), referred to as Test PLA by Intel, that is physically visible by its regular appearance on the die. This single piece of combinational logic replaces what would otherwise be dozens of multi-cycle conditional branches in the microcode. Instead of testing privilege rules sequentially, the microcode issues a single protection test operation, and the PLA evaluates all applicable rules in parallel, producing a complete decision in one evaluation: continue, fault, or redirect to a gate handler.
"I'd rather take a hard, clear action now and build from a position we believe in than manage a slow reduction of people toward the same outcome," he wrote.