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| Next: <a href="RTL.html#RTL" accesskey="n" rel="next">RTL</a>, Previous: <a href="GIMPLE.html#GIMPLE" accesskey="p" rel="prev">GIMPLE</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> |
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| <a name="Analysis-and-Optimization-of-GIMPLE-tuples"></a> |
| <h2 class="chapter">12 Analysis and Optimization of GIMPLE tuples</h2> |
| <a name="index-Tree-SSA"></a> |
| <a name="index-Optimization-infrastructure-for-GIMPLE"></a> |
| |
| <p>GCC uses three main intermediate languages to represent the program |
| during compilation: GENERIC, GIMPLE and RTL. GENERIC is a |
| language-independent representation generated by each front end. It |
| is used to serve as an interface between the parser and optimizer. |
| GENERIC is a common representation that is able to represent programs |
| written in all the languages supported by GCC. |
| </p> |
| <p>GIMPLE and RTL are used to optimize the program. GIMPLE is used for |
| target and language independent optimizations (e.g., inlining, |
| constant propagation, tail call elimination, redundancy elimination, |
| etc). Much like GENERIC, GIMPLE is a language independent, tree based |
| representation. However, it differs from GENERIC in that the GIMPLE |
| grammar is more restrictive: expressions contain no more than 3 |
| operands (except function calls), it has no control flow structures |
| and expressions with side-effects are only allowed on the right hand |
| side of assignments. See the chapter describing GENERIC and GIMPLE |
| for more details. |
| </p> |
| <p>This chapter describes the data structures and functions used in the |
| GIMPLE optimizers (also known as “tree optimizers” or “middle |
| end”). In particular, it focuses on all the macros, data structures, |
| functions and programming constructs needed to implement optimization |
| passes for GIMPLE. |
| </p> |
| <table class="menu" border="0" cellspacing="0"> |
| <tr><td align="left" valign="top">• <a href="Annotations.html#Annotations" accesskey="1">Annotations</a>:</td><td> </td><td align="left" valign="top">Attributes for variables. |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="SSA-Operands.html#SSA-Operands" accesskey="2">SSA Operands</a>:</td><td> </td><td align="left" valign="top">SSA names referenced by GIMPLE statements. |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="SSA.html#SSA" accesskey="3">SSA</a>:</td><td> </td><td align="left" valign="top">Static Single Assignment representation. |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="Alias-analysis.html#Alias-analysis" accesskey="4">Alias analysis</a>:</td><td> </td><td align="left" valign="top">Representing aliased loads and stores. |
| </td></tr> |
| <tr><td align="left" valign="top">• <a href="Memory-model.html#Memory-model" accesskey="5">Memory model</a>:</td><td> </td><td align="left" valign="top">Memory model used by the middle-end. |
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| </table> |
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| Next: <a href="RTL.html#RTL" accesskey="n" rel="next">RTL</a>, Previous: <a href="GIMPLE.html#GIMPLE" accesskey="p" rel="prev">GIMPLE</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p> |
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