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<title>[195903] trunk/Websites/webkit.org</title>
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<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/195903">195903</a></dd>
<dt>Author</dt> <dd>fpizlo@apple.com</dd>
<dt>Date</dt> <dd>2016-01-30 12:06:53 -0800 (Sat, 30 Jan 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>Improve the style of B3 documentation
https://bugs.webkit.org/show_bug.cgi?id=153674
Reviewed by Oliver Hunt.
This makes the style of the B3 documentation look like the Wiki, which I think is
appropriate for the kind of content that we're putting into it - in particular, the font
is the perfect size for dense content. The style also doesn't require much spoonfeeding
from the HTML side so you can write nice looking documentation by just using really
basic HTML constructs.
* docs/b3/assembly-intermediate-representation.html:
* docs/b3/index.html:
* docs/b3/intermediate-representation.html:
* docs/b3/style.css:</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkWebsiteswebkitorgChangeLog">trunk/Websites/webkit.org/ChangeLog</a></li>
<li><a href="#trunkWebsiteswebkitorgdocsb3assemblyintermediaterepresentationhtml">trunk/Websites/webkit.org/docs/b3/assembly-intermediate-representation.html</a></li>
<li><a href="#trunkWebsiteswebkitorgdocsb3indexhtml">trunk/Websites/webkit.org/docs/b3/index.html</a></li>
<li><a href="#trunkWebsiteswebkitorgdocsb3intermediaterepresentationhtml">trunk/Websites/webkit.org/docs/b3/intermediate-representation.html</a></li>
<li><a href="#trunkWebsiteswebkitorgdocsb3stylecss">trunk/Websites/webkit.org/docs/b3/style.css</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkWebsiteswebkitorgChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Websites/webkit.org/ChangeLog (195902 => 195903)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Websites/webkit.org/ChangeLog 2016-01-30 20:01:45 UTC (rev 195902)
+++ trunk/Websites/webkit.org/ChangeLog 2016-01-30 20:06:53 UTC (rev 195903)
</span><span class="lines">@@ -1,3 +1,21 @@
</span><ins>+2016-01-30 Filip Pizlo <fpizlo@apple.com>
+
+ Improve the style of B3 documentation
+ https://bugs.webkit.org/show_bug.cgi?id=153674
+
+ Reviewed by Oliver Hunt.
+
+ This makes the style of the B3 documentation look like the Wiki, which I think is
+ appropriate for the kind of content that we're putting into it - in particular, the font
+ is the perfect size for dense content. The style also doesn't require much spoonfeeding
+ from the HTML side so you can write nice looking documentation by just using really
+ basic HTML constructs.
+
+ * docs/b3/assembly-intermediate-representation.html:
+ * docs/b3/index.html:
+ * docs/b3/intermediate-representation.html:
+ * docs/b3/style.css:
+
</ins><span class="cx"> 2016-01-29 Filip Pizlo <fpizlo@apple.com>
</span><span class="cx">
</span><span class="cx"> Clean up the B3 documentation a bit
</span></span></pre></div>
<a id="trunkWebsiteswebkitorgdocsb3assemblyintermediaterepresentationhtml"></a>
<div class="modfile"><h4>Modified: trunk/Websites/webkit.org/docs/b3/assembly-intermediate-representation.html (195902 => 195903)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Websites/webkit.org/docs/b3/assembly-intermediate-representation.html 2016-01-30 20:01:45 UTC (rev 195902)
+++ trunk/Websites/webkit.org/docs/b3/assembly-intermediate-representation.html 2016-01-30 20:06:53 UTC (rev 195903)
</span><span class="lines">@@ -1,9 +1,18 @@
</span><span class="cx"> <html>
</span><del>- <head>
- <title>Assembly Intermediate Representation</title>
- <link rel="stylesheet" type="text/css" href="style.css">
- </head>
- <body>
</del><ins>+<head>
+ <title>Assembly Intermediate Representation</title>
+ <link rel="stylesheet" type="text/css" href="style.css">
+</head>
+<body>
+ <div id="banner">
+ <a href="http://www.webkit.org/" class="banner-link">
+ <div id="logo" class="site-logo">
+ WebKit
+ <span class="tagline">Open Source Web Browser</span>
+ </div>
+ </a>
+ </div>
+ <div id="contents">
</ins><span class="cx"> <h1><a href="index.html">Bare Bones Backend</a> / Assembly Intermediate Representation</h1>
</span><span class="cx"> <p>The B3 compiler converts SSA procedures into efficient machine code by first converting
</span><span class="cx"> them to a form that reveals machine details, like registers. This form is called Assembly
</span><span class="lines">@@ -14,9 +23,11 @@
</span><span class="cx"> which method name to use and its args indicate the arguments to pass to that method. We
</span><span class="cx"> use code generation to create a massive switch statement that turns the reflective Insts
</span><span class="cx"> into actual calls to MacroAssembler. Consequently, we can "add" new instructions to Air
</span><del>- usually by just editing the AirOpcode.opcodes file.</p>
</del><ins>+ usually by just editing the <a href="http://trac.webkit.org/browser/trunk/Source/JavaScriptCore/b3/air/AirOpcode.opcodes">AirOpcode.opcodes</a>
+ file.</p>
</ins><span class="cx">
</span><span class="cx"> <p><a href="https://bugs.webkit.org/show_bug.cgi?id=153668">FIXME: Add more text here.</a></p>
</span><del>- </body>
</del><ins>+ </div>
+</body>
</ins><span class="cx"> </html>
</span><span class="cx">
</span></span></pre></div>
<a id="trunkWebsiteswebkitorgdocsb3indexhtml"></a>
<div class="modfile"><h4>Modified: trunk/Websites/webkit.org/docs/b3/index.html (195902 => 195903)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Websites/webkit.org/docs/b3/index.html 2016-01-30 20:01:45 UTC (rev 195902)
+++ trunk/Websites/webkit.org/docs/b3/index.html 2016-01-30 20:06:53 UTC (rev 195903)
</span><span class="lines">@@ -1,9 +1,18 @@
</span><span class="cx"> <html>
</span><del>- <head>
- <title>Bare Bones Backend</title>
- <link rel="stylesheet" type="text/css" href="style.css">
- </head>
- <body>
</del><ins>+<head>
+ <title>Bare Bones Backend</title>
+ <link rel="stylesheet" type="text/css" href="style.css">
+</head>
+<body>
+ <div id="banner">
+ <a href="http://www.webkit.org/" class="banner-link">
+ <div id="logo" class="site-logo">
+ WebKit
+ <span class="tagline">Open Source Web Browser</span>
+ </div>
+ </a>
+ </div>
+ <div id="contents">
</ins><span class="cx"> <h1>Bare Bones Backend</h1>
</span><span class="cx"> <p>The Bare Bones Backend, or B3 for short, is WebKit's optimizing JIT for procedures
</span><span class="cx"> containing C-like code. It's currently used as the default backend for the
</span><span class="lines">@@ -31,9 +40,9 @@
</span><span class="cx"> root->appendNew<Const64Value>(proc, Origin(), 2)));
</span><span class="cx">
</span><span class="cx"> std::unique_ptr&lt;Compilation&gt; compilation = std::make_unique&lt;Compilation&gt;(vm, proc);
</span><del>-int64_t (*function)(int64_t) = static_cast&lt;int64_t (*)(int64_t)&gt;(compilation->code().executableAddress());
</del><ins>+int64_t (*function)(int64_t) = bitwise_cast&lt;int64_t (*)(int64_t)&gt;(compilation->code().executableAddress());
</ins><span class="cx">
</span><del>-printf("%d\n", function(42)); // prints 44</code></pre>
</del><ins>+printf("%lld\n", function(42)); // prints 44</code></pre>
</ins><span class="cx">
</span><span class="cx"> <p>When compiled, the resulting machine code looks like this:</p>
</span><span class="cx">
</span><span class="lines">@@ -162,7 +171,8 @@
</span><span class="cx"> Int32 @7 = Load8S(@6, ControlDependent|Reads:Top)
</span><span class="cx"> Int32 @8 = Const32(42)
</span><span class="cx"> Int32 @9 = LessThan(@7, $42(@8))
</span><del>-Void @10 = Check(@9:WarmAny, generator = 0x103fe1010, earlyClobbered = [], lateClobbered = [], usedRegisters = [], ExitsSideways|Reads:Top)</code></pre>
</del><ins>+Void @10 = Check(@9:WarmAny, generator = 0x103fe1010, earlyClobbered = [], lateClobbered = [],
+ usedRegisters = [], ExitsSideways|Reads:Top)</code></pre>
</ins><span class="cx">
</span><span class="cx"> <p>Is turned into the following Air:</p>
</span><span class="cx">
</span><span class="lines">@@ -188,7 +198,8 @@
</span><span class="cx"> from Air's object-oriented way of representing those instructions to the target's machine
</span><span class="cx"> code. We use JavaScriptCore's macro assembler for this purpose.</p>
</span><span class="cx">
</span><del>- </body>
</del><ins>+ </div>
+</body>
</ins><span class="cx"> </html>
</span><span class="cx">
</span><span class="cx">
</span></span></pre></div>
<a id="trunkWebsiteswebkitorgdocsb3intermediaterepresentationhtml"></a>
<div class="modfile"><h4>Modified: trunk/Websites/webkit.org/docs/b3/intermediate-representation.html (195902 => 195903)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Websites/webkit.org/docs/b3/intermediate-representation.html 2016-01-30 20:01:45 UTC (rev 195902)
+++ trunk/Websites/webkit.org/docs/b3/intermediate-representation.html 2016-01-30 20:06:53 UTC (rev 195903)
</span><span class="lines">@@ -1,9 +1,18 @@
</span><span class="cx"> <html>
</span><del>- <head>
- <title>B3 Intermediate Representation</title>
- <link rel="stylesheet" type="text/css" href="style.css">
- </head>
- <body>
</del><ins>+<head>
+ <title>B3 Intermediate Representation</title>
+ <link rel="stylesheet" type="text/css" href="style.css">
+</head>
+<body>
+ <div id="banner">
+ <a href="http://www.webkit.org/" class="banner-link">
+ <div id="logo" class="site-logo">
+ WebKit
+ <span class="tagline">Open Source Web Browser</span>
+ </div>
+ </a>
+ </div>
+ <div id="contents">
</ins><span class="cx"> <h1><a href="index.html">Bare Bones Backend</a> / B3 Intermediate Representation</h1>
</span><span class="cx"> <p>B3 IR is a C-like SSA representation of a procedure. A procedure has a root block at
</span><span class="cx"> which it starts execution when it is invoked. A procedure does not have to terminate, but
</span><span class="lines">@@ -193,12 +202,12 @@
</span><span class="cx">
</span><span class="cx"> <dt>T Div(T, T)</dt>
</span><span class="cx"> <dd>Works with any type except Void. For integer types, this represents signed division
</span><del>- with round-to-zero. Its behavior is undefined for x/0 or -2`^`31/-1. For floating
</del><ins>+ with round-to-zero. Its behavior is undefined for x/0 or -2<sup>31</sup>/-1. For floating
</ins><span class="cx"> point types, this represents division according to the IEEE 854 spec.</dd>
</span><span class="cx">
</span><span class="cx"> <dt>T Mod(T, T)</dt>
</span><span class="cx"> <dd>Works with any type except Void. For integer types, this represents signed modulo.
</span><del>- Its behavior is undefined for x%0 or -2`^`31%-1. For floating point types, this
</del><ins>+ Its behavior is undefined for x%0 or -2<sup>31</sup>%-1. For floating point types, this
</ins><span class="cx"> represents modulo according to "fmod()".</dd>
</span><span class="cx">
</span><span class="cx"> <dt>T Neg(T)</dt>
</span><span class="lines">@@ -209,13 +218,13 @@
</span><span class="cx"> <dt>T ChillDiv(T, T)</dt>
</span><span class="cx"> <dd>Chill division. Valid for Int32 and Int64. An operation is said to be chill if it
</span><span class="cx"> returns a sensible value whenever its non-chill form would have had undefined behavior.
</span><del>- ChillDiv turns x/0 into 0 and -2`^`31/-1 into -2`^`31. This is a separate opcode
</del><ins>+ ChillDiv turns x/0 into 0 and -2<sup>31</sup>/-1 into -2<sup>31</sup>. This is a separate opcode
</ins><span class="cx"> because it's exactly the semantics of division on ARM64, and it's also exactly the
</span><span class="cx"> semantics that JavaScript wants for "(x/y)|0".</dd>
</span><span class="cx">
</span><span class="cx"> <dt>T ChillMod(T, T)</dt>
</span><del>- <dd>Chill modulo. Valid for Int32 and Int64. ChllMod turns x%0 into 0 and -2`^`31%-1
- into 0.</dd>
</del><ins>+ <dd>Chill modulo. Valid for Int32 and Int64. ChllMod turns x%0 into 0 and
+ -2<sup>31</sup>%-1 into 0.</dd>
</ins><span class="cx">
</span><span class="cx"> <dt>T BitAnd(T, T)</dt>
</span><span class="cx"> <dd>Bitwise and. Valid for Int32 and Int64.</dd>
</span><span class="lines">@@ -515,6 +524,7 @@
</span><span class="cx"> transformations.</dd>
</span><span class="cx"> </dl>
</span><span class="cx">
</span><del>- </body>
</del><ins>+ </div>
+</body>
</ins><span class="cx"> </html>
</span><span class="cx">
</span></span></pre></div>
<a id="trunkWebsiteswebkitorgdocsb3stylecss"></a>
<div class="modfile"><h4>Modified: trunk/Websites/webkit.org/docs/b3/style.css (195902 => 195903)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Websites/webkit.org/docs/b3/style.css 2016-01-30 20:01:45 UTC (rev 195902)
+++ trunk/Websites/webkit.org/docs/b3/style.css 2016-01-30 20:06:53 UTC (rev 195903)
</span><span class="lines">@@ -1,6 +1,126 @@
</span><ins>+body {
+ background: #fff;
+ color: #000;
+ margin: 10px;
+ padding: 0;
+}
+body, th, tr {
+ font: normal 13px Verdana,Arial,'Bitstream Vera Sans',Helvetica,sans-serif;
+}
+h1, h2, h3, h4 {
+ font-family: Arial,Verdana,'Bitstream Vera Sans',Helvetica,sans-serif;
+ font-weight: bold;
+ letter-spacing: -0.018em;
+ page-break-after: avoid;
+}
+h1 { font-size: 19px; margin: .15em 1em 0.5em 0; text-indent: -10px }
+h2 { font-size: 17px; text-indent: -10px }
+h3 { font-size: 15px; text-indent: -10px }
+hr { border: none; border-top: 1px solid #ccb; margin: 2em 0 }
+address { font-style: normal }
+img { border: none }
+
+.underline { text-decoration: underline }
+ol.loweralpha { list-style-type: lower-alpha }
+ol.upperalpha { list-style-type: upper-alpha }
+ol.lowerroman { list-style-type: lower-roman }
+ol.upperroman { list-style-type: upper-roman }
+ol.arabic { list-style-type: decimal }
+
+.banner-link:link, .banner-link:visited {
+ text-decoration: none;
+ color: #b00;
+ border-bottom: 0px;
+}
+
+/* Link styles */
+:link, :visited {
+ text-decoration: none;
+ color: #b00;
+ border-bottom: 1px dotted #bbb;
+}
+h1 :link, h1 :visited ,h2 :link, h2 :visited, h3 :link, h3 :visited,
+h4 :link, h4 :visited, h5 :link, h5 :visited, h6 :link, h6 :visited {
+ color: inherit;
+}
+
+/* Heading anchors */
+.anchor:link, .anchor:visited {
+ border: none;
+ color: #d7d7d7;
+ font-size: .8em;
+ vertical-align: text-top;
+}
+* > .anchor:link, * > .anchor:visited {
+ visibility: hidden;
+}
+h1:hover .anchor, h2:hover .anchor, h3:hover .anchor,
+h4:hover .anchor, h5:hover .anchor, h6:hover .anchor,
+span:hover .anchor {
+ visibility: visible;
+}
+
+a.missing:link, a.missing:visited, a.missing, span.missing,
+a.forbidden, span.forbidden { color: #998 }
+a.missing:hover { color: #000 }
+a.closed:link, a.closed:visited, span.closed { text-decoration: line-through }
+
+pre {
+ background: #f7f7f7;
+ border: 1px solid #d7d7d7;
+ margin: 1em 1.75em;
+ padding: .25em;
+ overflow: auto;
+}
+
+div.code {
+ background: #f7f7f7;
+ border: 1px solid #d7d7d7;
+ margin: 1em 1.75em;
+ padding: .25em;
+ overflow: auto
+}
+
+div.code pre { margin: 0; }
+
+dt {
+ font-weight: bold;
+}
</ins><span class="cx"> dd {
</span><del>- padding: 0 0 0.5em 0;
</del><ins>+ padding: 0 0 0.8em 0;
</ins><span class="cx"> }
</span><span class="cx"> dd:last-child {
</span><span class="cx"> padding: 0 0 0 0;
</span><span class="cx"> }
</span><ins>+
+/** Logo **/
+.site-logo {
+ font-size: 3rem;
+ line-height: 3rem;
+ font-weight: 200;
+ display: inline-block;
+ background: url('../../wp-content/themes/webkit/images/webkit.svg') no-repeat;
+ padding-left: 7rem;
+ color: #333;
+}
+
+.site-logo .tagline {
+ display: block;
+ font-size: 1.2rem;
+ line-height: 2rem;
+ letter-spacing: -0.05rem;
+ color: #666;
+}
+
+#contents {
+ font-size: 90%;
+ padding: 2em 2em 2em 2em
+}
+
+p {
+ margin: 0 0 0.8em 0;
+}
+
+p:last-child {
+ margin: 0 0 0 0;
+}
</ins></span></pre>
</div>
</div>
</body>
</html>