1 <!doctype html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> 2 <html> 3 <head> 4 <meta http-equiv="content-type" content="text/html; charset=iso-8859-1"> 5 <meta http-equiv="content-style-type" content="text/css"> 6 <link rel="stylesheet" type="text/css" href="style.css"> 7 <title>Optimizations</title> 8 </head> 9 <body> 10 11 <h2>Optimizations</h2> 12 13 The optimization step of ProGuard can be switched off with the 14 <a href="usage.html#dontoptimize"><code>-dontoptimize</code></a> option. For 15 more fine-grained control over individual optimizations, experts can use the 16 <a href="usage.html#optimizations"><code>-optimizations</code></a> option, 17 with a filter based on the optimization names listed below. The filter works 18 like any <a href="usage.html#filters">filter</a> in ProGuard. 19 <p> 20 21 The following wildcards are supported: 22 23 <table cellspacing="10"> 24 <tr><td valign="top"><code><b>?</b></code></td> 25 <td>matches any single character in an optimization name.</td></tr> 26 <tr><td valign="top"><code><b>*</b></code></td> 27 <td>matches any part of an optimization name.</td></tr> 28 </table> 29 30 An optimization that is preceded by an exclamation mark '<b>!</b>' is 31 <i>excluded</i> from further attempts to match with <i>subsequent</i> 32 optimization names in the filter. Make sure to specify filters correctly, 33 since they are not checked for potential typos. 34 <p> 35 36 For example, 37 "<code>code/simplification/variable,code/simplification/arithmetic</code>" 38 only performs the two specified peephole optimizations. 39 <p> 40 41 For example, "<code>!method/propagation/*</code>" performs all optimizations, 42 except the ones that propagate values between methods. 43 <p> 44 45 For example, 46 "<code>!code/simplification/advanced,code/simplification/*</code>" only 47 performs all peephole optimizations. 48 <p> 49 Some optimizations necessarily imply other optimizations. These are then 50 indicated. Note that the list is likely to change over time, as optimizations 51 are added and reorganized. 52 <p> 53 54 <dl> 55 <dt><code><b>class/marking/final</b></code></dt> 56 <dd>Marks classes as final, whenever possible.</dd> 57 58 <dt><code><b>class/merging/vertical</b></code></dt> 59 <dd>Merges classes vertically in the class hierarchy, whenever possible.</dd> 60 61 <dt><code><b>class/merging/horizontal</b></code></dt> 62 <dd>Merges classes horizontally in the class hierarchy, whenever possible.</dd> 63 64 <dt><div>(⇒ <code>code/removal/advanced</code>)</div> 65 <code><b>field/removal/writeonly</b></code></dt> 66 <dd>Removes write-only fields.</dd> 67 68 <dt><code><b>field/marking/private</b></code></dt> 69 <dd>Marks fields as private, whenever possible.</dd> 70 71 <dt><div>(⇒ <code>code/simplification/advanced</code>)</div> 72 <code><b>field/propagation/value</b></code></dt> 73 <dd>Propagates the values of fields across methods.</dd> 74 75 <dt><code><b>method/marking/private</b></code></dt> 76 <dd>Marks methods as private, whenever possible (<i>devirtualization</i>).</dd> 77 78 <dt><div>(⇒ <code>code/removal/advanced</code>)</div> 79 <code><b>method/marking/static</b></code></dt> 80 <dd>Marks methods as static, whenever possible (<i>devirtualization</i>).</dd> 81 82 <dt><code><b>method/marking/final</b></code></dt> 83 <dd>Marks methods as final, whenever possible.</dd> 84 85 <dt><div>(⇒ <code>code/removal/advanced</code>)</div> 86 <code><b>method/removal/parameter</b></code></dt> 87 <dd>Removes unused method parameters.</dd> 88 89 <dt><div>(⇒ <code>code/simplification/advanced</code>)</div> 90 <code><b>method/propagation/parameter</b></code></dt> 91 <dd>Propagates the values of method parameters from method invocations to 92 the invoked methods.</dd> 93 94 <dt><div>(⇒ <code>code/simplification/advanced</code>)</div> 95 <code><b>method/propagation/returnvalue</b></code></dt> 96 <dd>Propagates the values of method return values from methods to their 97 invocations.</dd> 98 99 <dt><code><b>method/inlining/short</b></code></dt> 100 <dd>Inlines short methods.</dd> 101 102 <dt><code><b>method/inlining/unique</b></code></dt> 103 <dd>Inlines methods that are only called once.</dd> 104 105 <dt><code><b>method/inlining/tailrecursion</b></code></dt> 106 <dd>Simplifies tail recursion calls, whenever possible.</dd> 107 108 <dt><code><b>code/merging</b></code></dt> 109 <dd>Merges identical blocks of code by modifying branch targets.</dd> 110 111 <dt><code><b>code/simplification/variable</b></code></dt> 112 <dd>Performs peephole optimizations for variable loading and storing.</dd> 113 114 <dt><code><b>code/simplification/arithmetic</b></code></dt> 115 <dd>Performs peephole optimizations for arithmetic instructions.</dd> 116 117 <dt><code><b>code/simplification/cast</b></code></dt> 118 <dd>Performs peephole optimizations for casting operations.</dd> 119 120 <dt><code><b>code/simplification/field</b></code></dt> 121 <dd>Performs peephole optimizations for field loading and storing.</dd> 122 123 <dt><div>(⇒ <code>code/removal/simple</code>)</div> 124 <code><b>code/simplification/branch</b></code></dt> 125 <dd>Performs peephole optimizations for branch instructions.</dd> 126 127 <dt><div>(<i>best used with</i> <code>code/removal/advanced</code>)</div> 128 <code><b>code/simplification/advanced</b></code></dt> 129 <dd>Simplifies code based on control flow analysis and data flow 130 analysis.</dd> 131 132 <dt><div>(⇒ <code>code/removal/exception</code>)</div> 133 <code><b>code/removal/advanced</b></code></dt> 134 <dd>Removes dead code based on control flow analysis and data flow 135 analysis.</dd> 136 137 <dt><div>(⇒ <code>code/removal/exception</code>)</div> 138 <code><b>code/removal/simple</b></code></dt> 139 <dd>Removes dead code based on a simple control flow analysis.</dd> 140 141 <dt><code><b>code/removal/variable</b></code></dt> 142 <dd>Removes unused variables from the local variable frame.</dd> 143 144 <dt><code><b>code/removal/exception</b></code></dt> 145 <dd>Removes exceptions with empty catch blocks.</dd> 146 147 <dt><code><b>code/allocation/variable</b></code></dt> 148 <dd>Optimizes variable allocation on the local variable frame.</dd> 149 </dl> 150 <p> 151 152 <hr> 153 <address> 154 Copyright © 2002-2009 155 <a href="http://www.graphics.cornell.edu/~eric/">Eric Lafortune</a>. 156 </address> 157 </body> 158 </html> 159
