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diff --git a/2024/01/23/G-Machine/index.html b/2024/01/23/G-Machine/index.html new file mode 100644 index 00000000..ff1d742e --- /dev/null +++ b/2024/01/23/G-Machine/index.html @@ -0,0 +1,240 @@ +<!DOCTYPE html> +<html lang="en"> + <head> + <meta charset="UTF-8"> +<meta name="viewport" + content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"> +<meta http-equiv="X-UA-Compatible" content="ie=edge"> + + <meta name="author" content="韩暮秋"> + + + <meta name="subtitle" content="暮秋小屋"> + + + <meta name="description" content="这里是暮秋小屋，思念和灵感的寄存处"> + + + <meta name="keywords" content="韩暮秋,MuqiuHan"> + + + + +<title>G-Machine | 暮秋小屋</title> + + + + + +<style> + @import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Noto+Sans+SC:wght@300;400;500;700&family=Roboto+Mono&display=swap'); +</style> + + + + <!-- stylesheets list from _config.yml --> + + <link rel="stylesheet" href="/css/style.css"> + + + + + + <!-- scripts list from _config.yml --> + + <script src="/js/frame.js"></script> + + + + + + <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script> + <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script> + + + + + + + + <meta name="generator" content="Hexo 6.3.0"></head> + <body> + <div class="mask-border"> + </div> + + <div class="wrapper"> + + <div class="header"> + <div class="flex-container"> + <div class="header-inner"> + <div class="site-brand-container"> + <a href="/"> + + 暮秋小屋 + + </a> + </div> + <div id="menu-btn" class="menu-btn" onclick="toggleMenu()"> + Menu + </div> + <nav class="site-nav"> + <ul class="menu-list"> + + + <li class="menu-item"> + <a href="/">主页</a> + </li> + + + + <li class="menu-item"> + <a href="/categories/gallery/">日记本</a> + </li> + + + + <li class="menu-item"> + <a href="/tags/Medicine/">医学</a> + </li> + + + + <li class="menu-item"> + <a href="/tags/Technique/">计算机科学</a> + </li> + + + + <li class="menu-item"> + <a href="/tags/Life/">生活</a> + </li> + + + + <li class="menu-item"> + <a href="/about">关于</a> + </li> + + + + </ul> + </nav> + </div> + </div> +</div> + + + <div class="main"> + <div class="flex-container"> + <article id="post"> + + + <div class="post-head"> + <div class="post-info"> + <div class="tag-list"> + + + <span class="post-tag"> + <a href="/tags/Technique/"> + Technique + </a> + </span> + + + </div> + <div class="post-title"> + + + G-Machine + + + </div> + <span class="post-date"> + Jan 23, 2024 + </span> + </div> + <div class="post-img"> + + <div class="h-line-primary"></div> + + </div> +</div> + <div class="post-content"> + <ul> +<li><a target="_blank" rel="noopener" href="https://link.springer.com/chapter/10.1007/3-540-15975-4_50">The G-machine: A fast, graph-reduction evaluator</a></li> +</ul> +<p>G-Machine 是一种通过图规约来对函数式语言程序求值的抽象架构。<br>与组合子规约不同，组合子规约的control是从表达式图本身动态导出的，而G-Machine是由通过编译Application表达式导出的指令序列指定的。</p> +<hr> +<p>FP的程序基本上都可以用一个表达式的图表示，图计算机就是对这个图求值的机器，总的说来对图的求值是一个不停合并图上的节点生产新节点的过程。</p> +<p>例如：</p> +<figure class="highlight ocaml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">let</span> x = <span class="number">2</span> + <span class="number">3</span> <span class="keyword">in</span> </span><br><span class="line"> x * x</span><br></pre></td></tr></table></figure> + +<p>先计算出5，然后创建一个新的节点 <code>5 * 5</code>，然后再对这个节点求值，于是求值过程中就产生了很多临时的节点，这些中间节点也被叫做是 spine，求值过程是沿着 spine 进行的。</p> +<p>但是这样就产生了很多额外的开销，lambda lifting 里提到：可以把程序里，很多捕捉了外围绑定的闭包函数中的这些绑定，转换成函数的参数，从而消除闭包，得到的这个函数就可以自由脱离作用域，被静态的编译到机器码里。这些被 float out 的函数也叫 supercombinator.</p> +<p>在上面的代码中，如果不创建新的节点，顺序计算完了第一个 <code>x</code>，第二个 <code>x</code> 还会再被算一遍。</p> +<p>Spineless reduction 的概念：只有当面临需要重复计算的情况时，才去创建节点，不然就一路顺序算下去</p> +<ul> +<li><a target="_blank" rel="noopener" href="https://en.wikipedia.org/wiki/Graph_reduction">Graph reduction</a></li> +<li><a target="_blank" rel="noopener" href="https://en.wikipedia.org/wiki/Graph_reduction_machine">Graph reduction machine</a></li> +<li><a target="_blank" rel="noopener" href="https://www.zhihu.com/question/54834531/answer/144213668">https://www.zhihu.com/question/54834531/answer/144213668</a></li> +</ul> + +</div> + +<script> + window.onload = detectors(); +</script> + <div class="post-footer"> + <div class="h-line-primary"></div> + <nav class="post-nav"> + <div class="prev-item"> + + </div> + <div class="next-item"> + + <div class="icon arrow-right"></div> + <div class="post-link"> + <a href="/2024/01/23/%E6%85%A2%E6%80%A7%E8%82%BA%E6%BA%90%E6%80%A7%E5%BF%83%E8%84%8F%E7%97%85/">Next</a> + </div> + + </div> + </nav> +</div> + + + <div class="post-comment"> + + + + + + + +</div> + + +</article> + </div> + </div> + + <div class="footer"> + <div class="flex-container"> + <div class="footer-text"> + + + | + + + 希望路过的人可以添点柴火让这里暖和点 + + </div> + </div> +</div> + + </div> + + + + + </body> +</html> |