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| <title>Optimizations</title> |
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| |
| <h2>Optimizations</h2> |
| |
| The optimization step of ProGuard can be switched off with the |
| <a href="usage.html#dontoptimize"><code>-dontoptimize</code></a> option. For |
| more fine-grained control over individual optimizations, experts can use the |
| <a href="usage.html#optimizations"><code>-optimizations</code></a> option, |
| with a filter based on the optimization names listed below. The filter works |
| like any <a href="usage.html#filters">filter</a> in ProGuard. |
| <p> |
| |
| The following wildcards are supported: |
| |
| <table cellspacing="10"> |
| <tr><td valign="top"><code><b>?</b></code></td> |
| <td>matches any single character in an optimization name.</td></tr> |
| <tr><td valign="top"><code><b>*</b></code></td> |
| <td>matches any part of an optimization name.</td></tr> |
| </table> |
| |
| An optimization that is preceded by an exclamation mark '<b>!</b>' is |
| <i>excluded</i> from further attempts to match with <i>subsequent</i> |
| optimization names in the filter. Make sure to specify filters correctly, |
| since they are not checked for potential typos. |
| <p> |
| |
| For example, |
| "<code>code/simplification/variable,code/simplification/arithmetic</code>" |
| only performs the two specified peephole optimizations. |
| <p> |
| |
| For example, "<code>!method/propagation/*</code>" performs all optimizations, |
| except the ones that propagate values between methods. |
| <p> |
| |
| For example, |
| "<code>!code/simplification/advanced,code/simplification/*</code>" only |
| performs all peephole optimizations. |
| <p> |
| Some optimizations necessarily imply other optimizations. These are then |
| indicated. Note that the list is likely to change over time, as optimizations |
| are added and reorganized. |
| <p> |
| |
| <dl> |
| <dt><code><b>class/marking/final</b></code></dt> |
| <dd>Marks classes as final, whenever possible.</dd> |
| |
| <dt><code><b>class/merging/vertical</b></code></dt> |
| <dd>Merges classes vertically in the class hierarchy, whenever possible.</dd> |
| |
| <dt><code><b>class/merging/horizontal</b></code></dt> |
| <dd>Merges classes horizontally in the class hierarchy, whenever possible.</dd> |
| |
| <dt><div>(⇒ <code>code/removal/advanced</code>)</div> |
| <code><b>field/removal/writeonly</b></code></dt> |
| <dd>Removes write-only fields.</dd> |
| |
| <dt><code><b>field/marking/private</b></code></dt> |
| <dd>Marks fields as private, whenever possible.</dd> |
| |
| <dt><div>(⇒ <code>code/simplification/advanced</code>)</div> |
| <code><b>field/propagation/value</b></code></dt> |
| <dd>Propagates the values of fields across methods.</dd> |
| |
| <dt><code><b>method/marking/private</b></code></dt> |
| <dd>Marks methods as private, whenever possible (<i>devirtualization</i>).</dd> |
| |
| <dt><div>(⇒ <code>code/removal/advanced</code>)</div> |
| <code><b>method/marking/static</b></code></dt> |
| <dd>Marks methods as static, whenever possible (<i>devirtualization</i>).</dd> |
| |
| <dt><code><b>method/marking/final</b></code></dt> |
| <dd>Marks methods as final, whenever possible.</dd> |
| |
| <dt><div>(⇒ <code>code/removal/advanced</code>)</div> |
| <code><b>method/removal/parameter</b></code></dt> |
| <dd>Removes unused method parameters.</dd> |
| |
| <dt><div>(⇒ <code>code/simplification/advanced</code>)</div> |
| <code><b>method/propagation/parameter</b></code></dt> |
| <dd>Propagates the values of method parameters from method invocations to |
| the invoked methods.</dd> |
| |
| <dt><div>(⇒ <code>code/simplification/advanced</code>)</div> |
| <code><b>method/propagation/returnvalue</b></code></dt> |
| <dd>Propagates the values of method return values from methods to their |
| invocations.</dd> |
| |
| <dt><code><b>method/inlining/short</b></code></dt> |
| <dd>Inlines short methods.</dd> |
| |
| <dt><code><b>method/inlining/unique</b></code></dt> |
| <dd>Inlines methods that are only called once.</dd> |
| |
| <dt><code><b>method/inlining/tailrecursion</b></code></dt> |
| <dd>Simplifies tail recursion calls, whenever possible.</dd> |
| |
| <dt><code><b>code/merging</b></code></dt> |
| <dd>Merges identical blocks of code by modifying branch targets.</dd> |
| |
| <dt><code><b>code/simplification/variable</b></code></dt> |
| <dd>Performs peephole optimizations for variable loading and storing.</dd> |
| |
| <dt><code><b>code/simplification/arithmetic</b></code></dt> |
| <dd>Performs peephole optimizations for arithmetic instructions.</dd> |
| |
| <dt><code><b>code/simplification/cast</b></code></dt> |
| <dd>Performs peephole optimizations for casting operations.</dd> |
| |
| <dt><code><b>code/simplification/field</b></code></dt> |
| <dd>Performs peephole optimizations for field loading and storing.</dd> |
| |
| <dt><div>(⇒ <code>code/removal/simple</code>)</div> |
| <code><b>code/simplification/branch</b></code></dt> |
| <dd>Performs peephole optimizations for branch instructions.</dd> |
| |
| <dt><div>(<i>best used with</i> <code>code/removal/advanced</code>)</div> |
| <code><b>code/simplification/advanced</b></code></dt> |
| <dd>Simplifies code based on control flow analysis and data flow |
| analysis.</dd> |
| |
| <dt><div>(⇒ <code>code/removal/exception</code>)</div> |
| <code><b>code/removal/advanced</b></code></dt> |
| <dd>Removes dead code based on control flow analysis and data flow |
| analysis.</dd> |
| |
| <dt><div>(⇒ <code>code/removal/exception</code>)</div> |
| <code><b>code/removal/simple</b></code></dt> |
| <dd>Removes dead code based on a simple control flow analysis.</dd> |
| |
| <dt><code><b>code/removal/variable</b></code></dt> |
| <dd>Removes unused variables from the local variable frame.</dd> |
| |
| <dt><code><b>code/removal/exception</b></code></dt> |
| <dd>Removes exceptions with empty catch blocks.</dd> |
| |
| <dt><code><b>code/allocation/variable</b></code></dt> |
| <dd>Optimizes variable allocation on the local variable frame.</dd> |
| </dl> |
| <p> |
| |
| <hr> |
| <address> |
| Copyright © 2002-2009 |
| <a href="http://www.graphics.cornell.edu/~eric/">Eric Lafortune</a>. |
| </address> |
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