67 lines
2.8 KiB
HTML
67 lines
2.8 KiB
HTML
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<html lang="en">
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<head>
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<title>Local Calls - SBCL Internals</title>
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<link title="Top" rel="start" href="index.html#Top">
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<link rel="up" href="Calling-Convention.html#Calling-Convention" title="Calling Convention">
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<link rel="prev" href="Assembly-Routines.html#Assembly-Routines" title="Assembly Routines">
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<link rel="next" href="Full-Calls.html#Full-Calls" title="Full Calls">
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This manual is part of the SBCL software system. See the `README'
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file for more information.
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This manual is in the public domain and is provided with
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absolutely no warranty. See the `COPYING' and `CREDITS' files for
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</head>
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<body>
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<div class="node">
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<p>
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<a name="Local-Calls"></a>
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Next: <a rel="next" accesskey="n" href="Full-Calls.html#Full-Calls">Full Calls</a>,
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Previous: <a rel="previous" accesskey="p" href="Assembly-Routines.html#Assembly-Routines">Assembly Routines</a>,
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Up: <a rel="up" accesskey="u" href="Calling-Convention.html#Calling-Convention">Calling Convention</a>
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<hr>
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</div>
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<!-- node-name, next, previous, up -->
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<h3 class="section">2.2 Local Calls</h3>
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<p>Calls within a block, whatever a block is, can use a local
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calling convention in which the compiler knows where all of the
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values are to be stored, and thus can elide the check for number
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of return values, stack-pointer restoration, etc. Alternately,
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they can use the full unknown-values return convention while
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trying to short-circuit the call convention. There is probably
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some low-hanging fruit here in terms of CPU branch-prediction.
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<p>The local (known-values) calling convention is implemented by
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the <code>known-call-local</code> and <code>known-return</code> VOPs.
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<p>Local unknown-values calls are handled at the call site by the
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<code>call-local</code> and <code>mutiple-call-local</code> VOPs. The main difference
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between the full call and local call protocols here is that
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local calls use a different frame setup protocol, and will tend
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to not use the normal frame layout for the old frame-pointer and
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return-address.
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</body></html>
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