111 lines
4.7 KiB
HTML
111 lines
4.7 KiB
HTML
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
|
||
|
|
"http://www.w3.org/TR/html4/strict.dtd">
|
||
|
|
<html>
|
||
|
|
<head>
|
||
|
|
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
|
||
|
|
<title>Clang - Performance</title>
|
||
|
|
<link type="text/css" rel="stylesheet" href="menu.css">
|
||
|
|
<link type="text/css" rel="stylesheet" href="content.css">
|
||
|
|
<style type="text/css">
|
||
|
|
</style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
|
||
|
|
<!--#include virtual="menu.html.incl"-->
|
||
|
|
|
||
|
|
<div id="content">
|
||
|
|
|
||
|
|
<!--*************************************************************************-->
|
||
|
|
<h1>Clang - Performance</h1>
|
||
|
|
<!--*************************************************************************-->
|
||
|
|
|
||
|
|
<p>This page shows the compile time performance of Clang on two
|
||
|
|
interesting benchmarks:</p>
|
||
|
|
<ul>
|
||
|
|
<li><i>Sketch</i>: The Objective-C example application shipped on
|
||
|
|
Mac OS X as part of Xcode. <i>Sketch</i> is indicative of a
|
||
|
|
"typical" Objective-C app. The source itself has a relatively
|
||
|
|
small amount of code (~7,500 lines of source code), but it relies
|
||
|
|
on the extensive Cocoa APIs to build its functionality. Like many
|
||
|
|
Objective-C applications, it includes <tt>Cocoa/Cocoa.h</tt> in
|
||
|
|
all of its source files, which represents a significant stress
|
||
|
|
test of the front-end's performance on lexing, preprocessing,
|
||
|
|
parsing, and syntax analysis.</li>
|
||
|
|
<li><i>176.gcc</i>: This is the gcc-2.7.2.2 code base as present in
|
||
|
|
SPECINT 2000. In contrast to Sketch, <i>176.gcc</i> consists of a
|
||
|
|
large amount of C source code (~200,000 lines) with few system
|
||
|
|
dependencies. This stresses the back-end's performance on generating
|
||
|
|
assembly code and debug information.</li>
|
||
|
|
</ul>
|
||
|
|
|
||
|
|
<p>
|
||
|
|
For previous performance numbers, please
|
||
|
|
go <a href="performance-2008-10-31.html">here</a>.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<!--*************************************************************************-->
|
||
|
|
<h2><a name="experiments">Experiments</a></h2>
|
||
|
|
<!--*************************************************************************-->
|
||
|
|
|
||
|
|
<p>Measurements are done by running a full build (using xcodebuild or
|
||
|
|
make for Sketch and 176.gcc respectively) using Clang and gcc 4.2 as
|
||
|
|
compilers; gcc is run both with and without the new clang driver (ccc)
|
||
|
|
in order to evaluate the overhead of the driver itself.</p>
|
||
|
|
|
||
|
|
<p>In order to track the performance of various subsystems the timings
|
||
|
|
have been broken down into separate stages where possible. This is
|
||
|
|
done by over-riding the CC environment variable used during the build
|
||
|
|
to point to one of a few simple shell scripts which may skip part of
|
||
|
|
the build.</p>
|
||
|
|
|
||
|
|
<ul>
|
||
|
|
<li><tt>non-compiler</tt>: The overhead of the build system itself;
|
||
|
|
for Sketch this also includes the time to build/copy various
|
||
|
|
non-source code resource files.</li>
|
||
|
|
<li><tt>+ driver</tt>: Add execution of the driver, but do not execute any
|
||
|
|
commands (by using the -### driver option).</li>
|
||
|
|
<li><tt>+ pch gen</tt>: Add generation of PCH files.</li>
|
||
|
|
<li><tt>+ cpp</tt>: Add preprocessing of source files (this time is
|
||
|
|
include in syntax for gcc).</li>
|
||
|
|
<li><tt>+ parse</tt>: Add parsing of source files (this time is
|
||
|
|
include in syntax for gcc).</li>
|
||
|
|
<li><tt>+ syntax</tt>: Add semantic checking of source files (for
|
||
|
|
gcc, this includes preprocessing and parsing as well).</li>
|
||
|
|
<li><tt>+ IRgen</tt>: Add generation of LLVM IR (gcc has no
|
||
|
|
corresponding phase).</li>
|
||
|
|
<li><tt>+ codegen</tt>: Add generation of assembler files.</li>
|
||
|
|
<li><tt>+ assembler</tt>: Add assembler time to generate .o files.</li>
|
||
|
|
<li><tt>+ linker</tt>: Add linker time.</li>
|
||
|
|
</ul>
|
||
|
|
|
||
|
|
<p>This set of stages is chosen to be approximately additive, that is
|
||
|
|
each subsequent stage simply adds some additional processing. The
|
||
|
|
timings measure the delta of the given stage from the previous
|
||
|
|
one. For example, the timings for <tt>+ syntax</tt> below show the
|
||
|
|
difference of running with <tt>+ syntax</tt> versus running with <tt>+
|
||
|
|
parse</tt> (for clang) or <tt>+ driver</tt> with gcc. This amounts to
|
||
|
|
a fairly accurate measure of only the time to perform semantic
|
||
|
|
analysis (and preprocessing/parsing, in the case of gcc).</p>
|
||
|
|
|
||
|
|
<!--*************************************************************************-->
|
||
|
|
<h2><a name="timings">Timing Results</a></h2>
|
||
|
|
<!--*************************************************************************-->
|
||
|
|
|
||
|
|
<!--=======================================================================-->
|
||
|
|
<h3><a name="2009-03-02">2009-03-02</a></h3>
|
||
|
|
<!--=======================================================================-->
|
||
|
|
|
||
|
|
<a href="timing-data/2009-03-02/sketch.pdf">
|
||
|
|
<img class="img_slide"
|
||
|
|
src="timing-data/2009-03-02/sketch.png" alt="Sketch Timings">
|
||
|
|
</a>
|
||
|
|
|
||
|
|
<a href="timing-data/2009-03-02/176.gcc.pdf">
|
||
|
|
<img class="img_slide"
|
||
|
|
src="timing-data/2009-03-02/176.gcc.png" alt="176.gcc Timings">
|
||
|
|
</a>
|
||
|
|
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|