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<a name="Statement-and-operand-traversals"></a>
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Previous: <a href="Adding-a-new-GIMPLE-statement-code.html#Adding-a-new-GIMPLE-statement-code" accesskey="p" rel="prev">Adding a new GIMPLE statement code</a>, Up: <a href="GIMPLE.html#GIMPLE" accesskey="u" rel="up">GIMPLE</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="Statement-and-operand-traversals-1"></a>
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<h3 class="section">11.12 Statement and operand traversals</h3>
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<a name="index-Statement-and-operand-traversals"></a>
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<p>There are two functions available for walking statements and
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sequences: <code>walk_gimple_stmt</code> and <code>walk_gimple_seq</code>,
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accordingly, and a third function for walking the operands in a
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statement: <code>walk_gimple_op</code>.
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</p>
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<dl>
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<dt><a name="index-walk_005fgimple_005fstmt"></a>GIMPLE function: <em>tree</em> <strong>walk_gimple_stmt</strong> <em>(gimple_stmt_iterator *gsi, walk_stmt_fn callback_stmt, walk_tree_fn callback_op, struct walk_stmt_info *wi)</em></dt>
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<dd><p>This function is used to walk the current statement in <code>GSI</code>,
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optionally using traversal state stored in <code>WI</code>. If <code>WI</code> is <code>NULL</code>, no
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state is kept during the traversal.
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</p>
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<p>The callback <code>CALLBACK_STMT</code> is called. If <code>CALLBACK_STMT</code> returns
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true, it means that the callback function has handled all the
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operands of the statement and it is not necessary to walk its
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operands.
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</p>
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<p>If <code>CALLBACK_STMT</code> is <code>NULL</code> or it returns false, <code>CALLBACK_OP</code> is
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called on each operand of the statement via <code>walk_gimple_op</code>. If
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<code>walk_gimple_op</code> returns non-<code>NULL</code> for any operand, the remaining
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operands are not scanned.
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</p>
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<p>The return value is that returned by the last call to
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<code>walk_gimple_op</code>, or <code>NULL_TREE</code> if no <code>CALLBACK_OP</code> is specified.
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</p></dd></dl>
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<dl>
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<dt><a name="index-walk_005fgimple_005fop"></a>GIMPLE function: <em>tree</em> <strong>walk_gimple_op</strong> <em>(gimple stmt, walk_tree_fn callback_op, struct walk_stmt_info *wi)</em></dt>
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<dd><p>Use this function to walk the operands of statement <code>STMT</code>. Every
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operand is walked via <code>walk_tree</code> with optional state information
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in <code>WI</code>.
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</p>
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<p><code>CALLBACK_OP</code> is called on each operand of <code>STMT</code> via <code>walk_tree</code>.
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Additional parameters to <code>walk_tree</code> must be stored in <code>WI</code>. For
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each operand <code>OP</code>, <code>walk_tree</code> is called as:
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</p>
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<div class="smallexample">
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<pre class="smallexample">walk_tree (&<code>OP</code>, <code>CALLBACK_OP</code>, <code>WI</code>, <code>PSET</code>)
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</pre></div>
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<p>If <code>CALLBACK_OP</code> returns non-<code>NULL</code> for an operand, the remaining
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operands are not scanned. The return value is that returned by
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the last call to <code>walk_tree</code>, or <code>NULL_TREE</code> if no <code>CALLBACK_OP</code> is
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specified.
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</p></dd></dl>
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<dl>
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<dt><a name="index-walk_005fgimple_005fseq"></a>GIMPLE function: <em>tree</em> <strong>walk_gimple_seq</strong> <em>(gimple_seq seq, walk_stmt_fn callback_stmt, walk_tree_fn callback_op, struct walk_stmt_info *wi)</em></dt>
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<dd><p>This function walks all the statements in the sequence <code>SEQ</code>
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calling <code>walk_gimple_stmt</code> on each one. <code>WI</code> is as in
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<code>walk_gimple_stmt</code>. If <code>walk_gimple_stmt</code> returns non-<code>NULL</code>, the walk
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is stopped and the value returned. Otherwise, all the statements
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are walked and <code>NULL_TREE</code> returned.
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</p></dd></dl>
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Previous: <a href="Adding-a-new-GIMPLE-statement-code.html#Adding-a-new-GIMPLE-statement-code" accesskey="p" rel="prev">Adding a new GIMPLE statement code</a>, Up: <a href="GIMPLE.html#GIMPLE" accesskey="u" rel="up">GIMPLE</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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