<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>[183935] trunk/Source/JavaScriptCore</title>
</head>
<body>
<style type="text/css"><!--
#msg dl.meta { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; }
#msg dl.meta dt { float: left; width: 6em; font-weight: bold; }
#msg dt:after { content:':';}
#msg dl, #msg dt, #msg ul, #msg li, #header, #footer, #logmsg { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; }
#msg dl a { font-weight: bold}
#msg dl a:link { color:#fc3; }
#msg dl a:active { color:#ff0; }
#msg dl a:visited { color:#cc6; }
h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; }
#msg pre { overflow: auto; background: #ffc; border: 1px #fa0 solid; padding: 6px; }
#logmsg { background: #ffc; border: 1px #fa0 solid; padding: 1em 1em 0 1em; }
#logmsg p, #logmsg pre, #logmsg blockquote { margin: 0 0 1em 0; }
#logmsg p, #logmsg li, #logmsg dt, #logmsg dd { line-height: 14pt; }
#logmsg h1, #logmsg h2, #logmsg h3, #logmsg h4, #logmsg h5, #logmsg h6 { margin: .5em 0; }
#logmsg h1:first-child, #logmsg h2:first-child, #logmsg h3:first-child, #logmsg h4:first-child, #logmsg h5:first-child, #logmsg h6:first-child { margin-top: 0; }
#logmsg ul, #logmsg ol { padding: 0; list-style-position: inside; margin: 0 0 0 1em; }
#logmsg ul { text-indent: -1em; padding-left: 1em; }#logmsg ol { text-indent: -1.5em; padding-left: 1.5em; }
#logmsg > ul, #logmsg > ol { margin: 0 0 1em 0; }
#logmsg pre { background: #eee; padding: 1em; }
#logmsg blockquote { border: 1px solid #fa0; border-left-width: 10px; padding: 1em 1em 0 1em; background: white;}
#logmsg dl { margin: 0; }
#logmsg dt { font-weight: bold; }
#logmsg dd { margin: 0; padding: 0 0 0.5em 0; }
#logmsg dd:before { content:'\00bb';}
#logmsg table { border-spacing: 0px; border-collapse: collapse; border-top: 4px solid #fa0; border-bottom: 1px solid #fa0; background: #fff; }
#logmsg table th { text-align: left; font-weight: normal; padding: 0.2em 0.5em; border-top: 1px dotted #fa0; }
#logmsg table td { text-align: right; border-top: 1px dotted #fa0; padding: 0.2em 0.5em; }
#logmsg table thead th { text-align: center; border-bottom: 1px solid #fa0; }
#logmsg table th.Corner { text-align: left; }
#logmsg hr { border: none 0; border-top: 2px dashed #fa0; height: 1px; }
#header, #footer { color: #fff; background: #636; border: 1px #300 solid; padding: 6px; }
#patch { width: 100%; }
#patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;}
#patch .propset h4, #patch .binary h4 {margin:0;}
#patch pre {padding:0;line-height:1.2em;margin:0;}
#patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;}
#patch .propset .diff, #patch .binary .diff {padding:10px 0;}
#patch span {display:block;padding:0 10px;}
#patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;}
#patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;}
#patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;}
#patch .lines, .info {color:#888;background:#fff;}
--></style>
<div id="msg">
<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/183935">183935</a></dd>
<dt>Author</dt> <dd>ggaren@apple.com</dd>
<dt>Date</dt> <dd>2015-05-07 11:01:46 -0700 (Thu, 07 May 2015)</dd>
</dl>
<h3>Log Message</h3>
<pre>Don't branch when accessing the callee
https://bugs.webkit.org/show_bug.cgi?id=144645
Reviewed by Michael Saboff.
The branch was added in <http://trac.webkit.org/changeset/81040> without
explanation.
kling found it to be a performance problem. See <https://webkit.org/b/144586>.
Our theory of access to Registers is that it's up to the client to access
them in the right way. So, let's do that.
* interpreter/CallFrame.h:
(JSC::ExecState::callee):
(JSC::ExecState::setCallee): Call the field object instead of function
because nothing guarantees that it's a function.
* interpreter/ProtoCallFrame.h:
(JSC::ProtoCallFrame::callee):
(JSC::ProtoCallFrame::setCallee):
* interpreter/Register.h:
* runtime/JSObject.h:
(JSC::Register::object): Just do a cast like our other accessors do.
(JSC::Register::operator=):
(JSC::Register::function): Deleted.
(JSC::Register::withCallee): Deleted.</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkSourceJavaScriptCoreChangeLog">trunk/Source/JavaScriptCore/ChangeLog</a></li>
<li><a href="#trunkSourceJavaScriptCoreinterpreterCallFrameh">trunk/Source/JavaScriptCore/interpreter/CallFrame.h</a></li>
<li><a href="#trunkSourceJavaScriptCoreinterpreterProtoCallFrameh">trunk/Source/JavaScriptCore/interpreter/ProtoCallFrame.h</a></li>
<li><a href="#trunkSourceJavaScriptCoreinterpreterRegisterh">trunk/Source/JavaScriptCore/interpreter/Register.h</a></li>
<li><a href="#trunkSourceJavaScriptCoreruntimeJSObjecth">trunk/Source/JavaScriptCore/runtime/JSObject.h</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkSourceJavaScriptCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/ChangeLog (183934 => 183935)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/ChangeLog 2015-05-07 17:59:23 UTC (rev 183934)
+++ trunk/Source/JavaScriptCore/ChangeLog 2015-05-07 18:01:46 UTC (rev 183935)
</span><span class="lines">@@ -1,3 +1,32 @@
</span><ins>+2015-05-05 Geoffrey Garen <ggaren@apple.com>
+
+ Don't branch when accessing the callee
+ https://bugs.webkit.org/show_bug.cgi?id=144645
+
+ Reviewed by Michael Saboff.
+
+ The branch was added in <http://trac.webkit.org/changeset/81040> without
+ explanation.
+
+ kling found it to be a performance problem. See <https://webkit.org/b/144586>.
+
+ Our theory of access to Registers is that it's up to the client to access
+ them in the right way. So, let's do that.
+
+ * interpreter/CallFrame.h:
+ (JSC::ExecState::callee):
+ (JSC::ExecState::setCallee): Call the field object instead of function
+ because nothing guarantees that it's a function.
+ * interpreter/ProtoCallFrame.h:
+ (JSC::ProtoCallFrame::callee):
+ (JSC::ProtoCallFrame::setCallee):
+ * interpreter/Register.h:
+ * runtime/JSObject.h:
+ (JSC::Register::object): Just do a cast like our other accessors do.
+ (JSC::Register::operator=):
+ (JSC::Register::function): Deleted.
+ (JSC::Register::withCallee): Deleted.
+
</ins><span class="cx"> 2015-05-07 Dan Bernstein <mitz@apple.com>
</span><span class="cx">
</span><span class="cx"> <rdar://problem/19317140> [Xcode] Remove usage of AspenFamily.xcconfig in Source/
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreinterpreterCallFrameh"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/interpreter/CallFrame.h (183934 => 183935)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/interpreter/CallFrame.h 2015-05-07 17:59:23 UTC (rev 183934)
+++ trunk/Source/JavaScriptCore/interpreter/CallFrame.h 2015-05-07 18:01:46 UTC (rev 183935)
</span><span class="lines">@@ -43,7 +43,7 @@
</span><span class="cx"> class ExecState : private Register {
</span><span class="cx"> public:
</span><span class="cx"> JSValue calleeAsValue() const { return this[JSStack::Callee].jsValue(); }
</span><del>- JSObject* callee() const { return this[JSStack::Callee].function(); }
</del><ins>+ JSObject* callee() const { return this[JSStack::Callee].object(); }
</ins><span class="cx"> CodeBlock* codeBlock() const { return this[JSStack::CodeBlock].Register::codeBlock(); }
</span><span class="cx"> JSScope* scope(int scopeRegisterOffset) const
</span><span class="cx"> {
</span><span class="lines">@@ -259,7 +259,7 @@
</span><span class="cx"> static CallFrame* noCaller() { return 0; }
</span><span class="cx">
</span><span class="cx"> void setArgumentCountIncludingThis(int count) { static_cast<Register*>(this)[JSStack::ArgumentCount].payload() = count; }
</span><del>- void setCallee(JSObject* callee) { static_cast<Register*>(this)[JSStack::Callee] = Register::withCallee(callee); }
</del><ins>+ void setCallee(JSObject* callee) { static_cast<Register*>(this)[JSStack::Callee] = callee; }
</ins><span class="cx"> void setCodeBlock(CodeBlock* codeBlock) { static_cast<Register*>(this)[JSStack::CodeBlock] = codeBlock; }
</span><span class="cx"> void setReturnPC(void* value) { callerFrameAndPC().pc = reinterpret_cast<Instruction*>(value); }
</span><span class="cx">
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreinterpreterProtoCallFrameh"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/interpreter/ProtoCallFrame.h (183934 => 183935)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/interpreter/ProtoCallFrame.h 2015-05-07 17:59:23 UTC (rev 183934)
+++ trunk/Source/JavaScriptCore/interpreter/ProtoCallFrame.h 2015-05-07 18:01:46 UTC (rev 183935)
</span><span class="lines">@@ -44,8 +44,8 @@
</span><span class="cx"> CodeBlock* codeBlock() const { return codeBlockValue.Register::codeBlock(); }
</span><span class="cx"> void setCodeBlock(CodeBlock* codeBlock) { codeBlockValue = codeBlock; }
</span><span class="cx">
</span><del>- JSObject* callee() const { return calleeValue.Register::function(); }
- void setCallee(JSObject* callee) { calleeValue = Register::withCallee(callee); }
</del><ins>+ JSObject* callee() const { return calleeValue.Register::object(); }
+ void setCallee(JSObject* callee) { calleeValue = callee; }
</ins><span class="cx">
</span><span class="cx"> int argumentCountIncludingThis() const { return argCountAndCodeOriginValue.payload(); }
</span><span class="cx"> int argumentCount() const { return argumentCountIncludingThis() - 1; }
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreinterpreterRegisterh"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/interpreter/Register.h (183934 => 183935)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/interpreter/Register.h 2015-05-07 17:59:23 UTC (rev 183934)
+++ trunk/Source/JavaScriptCore/interpreter/Register.h 2015-05-07 18:01:46 UTC (rev 183935)
</span><span class="lines">@@ -56,12 +56,13 @@
</span><span class="cx"> Register& operator=(CallFrame*);
</span><span class="cx"> Register& operator=(CodeBlock*);
</span><span class="cx"> Register& operator=(JSScope*);
</span><ins>+ Register& operator=(JSObject*);
</ins><span class="cx">
</span><span class="cx"> int32_t i() const;
</span><span class="cx"> JSLexicalEnvironment* lexicalEnvironment() const;
</span><span class="cx"> CallFrame* callFrame() const;
</span><span class="cx"> CodeBlock* codeBlock() const;
</span><del>- JSObject* function() const;
</del><ins>+ JSObject* object() const;
</ins><span class="cx"> JSScope* scope() const;
</span><span class="cx"> int32_t unboxedInt32() const;
</span><span class="cx"> int64_t unboxedInt52() const;
</span><span class="lines">@@ -80,8 +81,6 @@
</span><span class="cx"> return r;
</span><span class="cx"> }
</span><span class="cx">
</span><del>- static Register withCallee(JSObject* callee);
-
</del><span class="cx"> private:
</span><span class="cx"> union {
</span><span class="cx"> EncodedJSValue value;
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreruntimeJSObjecth"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/runtime/JSObject.h (183934 => 183935)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/runtime/JSObject.h 2015-05-07 17:59:23 UTC (rev 183934)
+++ trunk/Source/JavaScriptCore/runtime/JSObject.h 2015-05-07 18:01:46 UTC (rev 183935)
</span><span class="lines">@@ -1452,18 +1452,15 @@
</span><span class="cx"> return methodTable()->defaultValue(this, exec, preferredType);
</span><span class="cx"> }
</span><span class="cx">
</span><del>-ALWAYS_INLINE JSObject* Register::function() const
</del><ins>+ALWAYS_INLINE JSObject* Register::object() const
</ins><span class="cx"> {
</span><del>- if (!jsValue())
- return 0;
</del><span class="cx"> return asObject(jsValue());
</span><span class="cx"> }
</span><span class="cx">
</span><del>-ALWAYS_INLINE Register Register::withCallee(JSObject* callee)
</del><ins>+ALWAYS_INLINE Register& Register::operator=(JSObject* object)
</ins><span class="cx"> {
</span><del>- Register r;
- r = JSValue(callee);
- return r;
</del><ins>+ u.value = JSValue::encode(JSValue(object));
+ return *this;
</ins><span class="cx"> }
</span><span class="cx">
</span><span class="cx"> inline size_t offsetInButterfly(PropertyOffset offset)
</span></span></pre>
</div>
</div>
</body>
</html>