197 lines
9.9 KiB
HTML
197 lines
9.9 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Copyright (C) 1988-2016 Free Software Foundation, Inc.
|
|
|
|
Permission is granted to copy, distribute and/or modify this document
|
|
under the terms of the GNU Free Documentation License, Version 1.3 or
|
|
any later version published by the Free Software Foundation; with the
|
|
Invariant Sections being "Funding Free Software", the Front-Cover
|
|
Texts being (a) (see below), and with the Back-Cover Texts being (b)
|
|
(see below). A copy of the license is included in the section entitled
|
|
"GNU Free Documentation License".
|
|
|
|
(a) The FSF's Front-Cover Text is:
|
|
|
|
A GNU Manual
|
|
|
|
(b) The FSF's Back-Cover Text is:
|
|
|
|
You have freedom to copy and modify this GNU Manual, like GNU
|
|
software. Copies published by the Free Software Foundation raise
|
|
funds for GNU development. -->
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<title>GNU Compiler Collection (GCC) Internals: Dispatch Tables</title>
|
|
|
|
<meta name="description" content="GNU Compiler Collection (GCC) Internals: Dispatch Tables">
|
|
<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Dispatch Tables">
|
|
<meta name="resource-type" content="document">
|
|
<meta name="distribution" content="global">
|
|
<meta name="Generator" content="makeinfo">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<link href="index.html#Top" rel="start" title="Top">
|
|
<link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
|
<link href="Assembler-Format.html#Assembler-Format" rel="up" title="Assembler Format">
|
|
<link href="Exception-Region-Output.html#Exception-Region-Output" rel="next" title="Exception Region Output">
|
|
<link href="Instruction-Output.html#Instruction-Output" rel="prev" title="Instruction Output">
|
|
<style type="text/css">
|
|
<!--
|
|
a.summary-letter {text-decoration: none}
|
|
blockquote.smallquotation {font-size: smaller}
|
|
div.display {margin-left: 3.2em}
|
|
div.example {margin-left: 3.2em}
|
|
div.indentedblock {margin-left: 3.2em}
|
|
div.lisp {margin-left: 3.2em}
|
|
div.smalldisplay {margin-left: 3.2em}
|
|
div.smallexample {margin-left: 3.2em}
|
|
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
|
|
div.smalllisp {margin-left: 3.2em}
|
|
kbd {font-style:oblique}
|
|
pre.display {font-family: inherit}
|
|
pre.format {font-family: inherit}
|
|
pre.menu-comment {font-family: serif}
|
|
pre.menu-preformatted {font-family: serif}
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
|
pre.smallexample {font-size: smaller}
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
|
pre.smalllisp {font-size: smaller}
|
|
span.nocodebreak {white-space:nowrap}
|
|
span.nolinebreak {white-space:nowrap}
|
|
span.roman {font-family:serif; font-weight:normal}
|
|
span.sansserif {font-family:sans-serif; font-weight:normal}
|
|
ul.no-bullet {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
|
|
<a name="Dispatch-Tables"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Exception-Region-Output.html#Exception-Region-Output" accesskey="n" rel="next">Exception Region Output</a>, Previous: <a href="Instruction-Output.html#Instruction-Output" accesskey="p" rel="prev">Instruction Output</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</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>
|
|
</div>
|
|
<hr>
|
|
<a name="Output-of-Dispatch-Tables"></a>
|
|
<h4 class="subsection">17.20.8 Output of Dispatch Tables</h4>
|
|
|
|
<p>This concerns dispatch tables.
|
|
</p>
|
|
<a name="index-dispatch-table"></a>
|
|
<dl>
|
|
<dt><a name="index-ASM_005fOUTPUT_005fADDR_005fDIFF_005fELT"></a>Macro: <strong>ASM_OUTPUT_ADDR_DIFF_ELT</strong> <em>(<var>stream</var>, <var>body</var>, <var>value</var>, <var>rel</var>)</em></dt>
|
|
<dd><p>A C statement to output to the stdio stream <var>stream</var> an assembler
|
|
pseudo-instruction to generate a difference between two labels.
|
|
<var>value</var> and <var>rel</var> are the numbers of two internal labels. The
|
|
definitions of these labels are output using
|
|
<code>(*targetm.asm_out.internal_label)</code>, and they must be printed in the same
|
|
way here. For example,
|
|
</p>
|
|
<div class="smallexample">
|
|
<pre class="smallexample">fprintf (<var>stream</var>, "\t.word L%d-L%d\n",
|
|
<var>value</var>, <var>rel</var>)
|
|
</pre></div>
|
|
|
|
<p>You must provide this macro on machines where the addresses in a
|
|
dispatch table are relative to the table’s own address. If defined, GCC
|
|
will also use this macro on all machines when producing PIC.
|
|
<var>body</var> is the body of the <code>ADDR_DIFF_VEC</code>; it is provided so that the
|
|
mode and flags can be read.
|
|
</p></dd></dl>
|
|
|
|
<dl>
|
|
<dt><a name="index-ASM_005fOUTPUT_005fADDR_005fVEC_005fELT"></a>Macro: <strong>ASM_OUTPUT_ADDR_VEC_ELT</strong> <em>(<var>stream</var>, <var>value</var>)</em></dt>
|
|
<dd><p>This macro should be provided on machines where the addresses
|
|
in a dispatch table are absolute.
|
|
</p>
|
|
<p>The definition should be a C statement to output to the stdio stream
|
|
<var>stream</var> an assembler pseudo-instruction to generate a reference to
|
|
a label. <var>value</var> is the number of an internal label whose
|
|
definition is output using <code>(*targetm.asm_out.internal_label)</code>.
|
|
For example,
|
|
</p>
|
|
<div class="smallexample">
|
|
<pre class="smallexample">fprintf (<var>stream</var>, "\t.word L%d\n", <var>value</var>)
|
|
</pre></div>
|
|
</dd></dl>
|
|
|
|
<dl>
|
|
<dt><a name="index-ASM_005fOUTPUT_005fCASE_005fLABEL"></a>Macro: <strong>ASM_OUTPUT_CASE_LABEL</strong> <em>(<var>stream</var>, <var>prefix</var>, <var>num</var>, <var>table</var>)</em></dt>
|
|
<dd><p>Define this if the label before a jump-table needs to be output
|
|
specially. The first three arguments are the same as for
|
|
<code>(*targetm.asm_out.internal_label)</code>; the fourth argument is the
|
|
jump-table which follows (a <code>jump_table_data</code> containing an
|
|
<code>addr_vec</code> or <code>addr_diff_vec</code>).
|
|
</p>
|
|
<p>This feature is used on system V to output a <code>swbeg</code> statement
|
|
for the table.
|
|
</p>
|
|
<p>If this macro is not defined, these labels are output with
|
|
<code>(*targetm.asm_out.internal_label)</code>.
|
|
</p></dd></dl>
|
|
|
|
<dl>
|
|
<dt><a name="index-ASM_005fOUTPUT_005fCASE_005fEND"></a>Macro: <strong>ASM_OUTPUT_CASE_END</strong> <em>(<var>stream</var>, <var>num</var>, <var>table</var>)</em></dt>
|
|
<dd><p>Define this if something special must be output at the end of a
|
|
jump-table. The definition should be a C statement to be executed
|
|
after the assembler code for the table is written. It should write
|
|
the appropriate code to stdio stream <var>stream</var>. The argument
|
|
<var>table</var> is the jump-table insn, and <var>num</var> is the label-number
|
|
of the preceding label.
|
|
</p>
|
|
<p>If this macro is not defined, nothing special is output at the end of
|
|
the jump-table.
|
|
</p></dd></dl>
|
|
|
|
<dl>
|
|
<dt><a name="index-TARGET_005fASM_005fEMIT_005fUNWIND_005fLABEL"></a>Target Hook: <em>void</em> <strong>TARGET_ASM_EMIT_UNWIND_LABEL</strong> <em>(FILE *<var>stream</var>, tree <var>decl</var>, int <var>for_eh</var>, int <var>empty</var>)</em></dt>
|
|
<dd><p>This target hook emits a label at the beginning of each FDE. It
|
|
should be defined on targets where FDEs need special labels, and it
|
|
should write the appropriate label, for the FDE associated with the
|
|
function declaration <var>decl</var>, to the stdio stream <var>stream</var>.
|
|
The third argument, <var>for_eh</var>, is a boolean: true if this is for an
|
|
exception table. The fourth argument, <var>empty</var>, is a boolean:
|
|
true if this is a placeholder label for an omitted FDE.
|
|
</p>
|
|
<p>The default is that FDEs are not given nonlocal labels.
|
|
</p></dd></dl>
|
|
|
|
<dl>
|
|
<dt><a name="index-TARGET_005fASM_005fEMIT_005fEXCEPT_005fTABLE_005fLABEL"></a>Target Hook: <em>void</em> <strong>TARGET_ASM_EMIT_EXCEPT_TABLE_LABEL</strong> <em>(FILE *<var>stream</var>)</em></dt>
|
|
<dd><p>This target hook emits a label at the beginning of the exception table.
|
|
It should be defined on targets where it is desirable for the table
|
|
to be broken up according to function.
|
|
</p>
|
|
<p>The default is that no label is emitted.
|
|
</p></dd></dl>
|
|
|
|
<dl>
|
|
<dt><a name="index-TARGET_005fASM_005fEMIT_005fEXCEPT_005fPERSONALITY"></a>Target Hook: <em>void</em> <strong>TARGET_ASM_EMIT_EXCEPT_PERSONALITY</strong> <em>(rtx <var>personality</var>)</em></dt>
|
|
<dd><p>If the target implements <code>TARGET_ASM_UNWIND_EMIT</code>, this hook may be used to emit a directive to install a personality hook into the unwind info. This hook should not be used if dwarf2 unwind info is used.
|
|
</p></dd></dl>
|
|
|
|
<dl>
|
|
<dt><a name="index-TARGET_005fASM_005fUNWIND_005fEMIT"></a>Target Hook: <em>void</em> <strong>TARGET_ASM_UNWIND_EMIT</strong> <em>(FILE *<var>stream</var>, rtx_insn *<var>insn</var>)</em></dt>
|
|
<dd><p>This target hook emits assembly directives required to unwind the
|
|
given instruction. This is only used when <code>TARGET_EXCEPT_UNWIND_INFO</code>
|
|
returns <code>UI_TARGET</code>.
|
|
</p></dd></dl>
|
|
|
|
<dl>
|
|
<dt><a name="index-TARGET_005fASM_005fUNWIND_005fEMIT_005fBEFORE_005fINSN"></a>Target Hook: <em>bool</em> <strong>TARGET_ASM_UNWIND_EMIT_BEFORE_INSN</strong></dt>
|
|
<dd><p>True if the <code>TARGET_ASM_UNWIND_EMIT</code> hook should be called before the assembly for <var>insn</var> has been emitted, false if the hook should be called afterward.
|
|
</p></dd></dl>
|
|
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Exception-Region-Output.html#Exception-Region-Output" accesskey="n" rel="next">Exception Region Output</a>, Previous: <a href="Instruction-Output.html#Instruction-Output" accesskey="p" rel="prev">Instruction Output</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</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>
|
|
</div>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|