aarch64-linux-gnu-4.9/share/doc/gccint/Instruction-Output.html - toolchains/linux-x86/gcc - Git at Google

 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 <html>
 <!-- Copyright (C) 1988-2015 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: Instruction Output</title>

 <meta name="description" content="GNU Compiler Collection (GCC) Internals: Instruction Output">
 <meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Instruction Output">
 <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="Dispatch-Tables.html#Dispatch-Tables" rel="next" title="Dispatch Tables">
 <link href="Macros-for-Initialization.html#Macros-for-Initialization" rel="prev" title="Macros for Initialization">
 <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="Instruction-Output"></a>
 <div class="header">
 <p>
 Next: <a href="Dispatch-Tables.html#Dispatch-Tables" accesskey="n" rel="next">Dispatch Tables</a>, Previous: <a href="Macros-for-Initialization.html#Macros-for-Initialization" accesskey="p" rel="prev">Macros for Initialization</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</a> &nbsp; [<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-Assembler-Instructions"></a>
 <h4 class="subsection">17.21.7 Output of Assembler Instructions</h4>

 <p>This describes assembler instruction output.
 </p>
 <dl>
 <dt><a name="index-REGISTER_005fNAMES"></a>Macro: <strong>REGISTER_NAMES</strong></dt>
 <dd><p>A C initializer containing the assembler&rsquo;s names for the machine
 registers, each one as a C string constant.  This is what translates
 register numbers in the compiler into assembler language.
 </p></dd></dl>

 <dl>
 <dt><a name="index-ADDITIONAL_005fREGISTER_005fNAMES"></a>Macro: <strong>ADDITIONAL_REGISTER_NAMES</strong></dt>
 <dd><p>If defined, a C initializer for an array of structures containing a name
 and a register number.  This macro defines additional names for hard
 registers, thus allowing the <code>asm</code> option in declarations to refer
 to registers using alternate names.
 </p></dd></dl>

 <dl>
 <dt><a name="index-OVERLAPPING_005fREGISTER_005fNAMES"></a>Macro: <strong>OVERLAPPING_REGISTER_NAMES</strong></dt>
 <dd><p>If defined, a C initializer for an array of structures containing a
 name, a register number and a count of the number of consecutive
 machine registers the name overlaps.  This macro defines additional
 names for hard registers, thus allowing the <code>asm</code> option in
 declarations to refer to registers using alternate names.  Unlike
 <code>ADDITIONAL_REGISTER_NAMES</code>, this macro should be used when the
 register name implies multiple underlying registers.
 </p>
 <p>This macro should be used when it is important that a clobber in an
 <code>asm</code> statement clobbers all the underlying values implied by the
 register name.  For example, on ARM, clobbering the double-precision
 VFP register &ldquo;d0&rdquo; implies clobbering both single-precision registers
 &ldquo;s0&rdquo; and &ldquo;s1&rdquo;.
 </p></dd></dl>

 <dl>
 <dt><a name="index-ASM_005fOUTPUT_005fOPCODE"></a>Macro: <strong>ASM_OUTPUT_OPCODE</strong> <em>(<var>stream</var>, <var>ptr</var>)</em></dt>
 <dd><p>Define this macro if you are using an unusual assembler that
 requires different names for the machine instructions.
 </p>
 <p>The definition is a C statement or statements which output an
 assembler instruction opcode to the stdio stream <var>stream</var>.  The
 macro-operand <var>ptr</var> is a variable of type <code>char *</code> which
 points to the opcode name in its &ldquo;internal&rdquo; form&mdash;the form that is
 written in the machine description.  The definition should output the
 opcode name to <var>stream</var>, performing any translation you desire, and
 increment the variable <var>ptr</var> to point at the end of the opcode
 so that it will not be output twice.
 </p>
 <p>In fact, your macro definition may process less than the entire opcode
 name, or more than the opcode name; but if you want to process text
 that includes &lsquo;<samp>%</samp>&rsquo;-sequences to substitute operands, you must take
 care of the substitution yourself.  Just be sure to increment
 <var>ptr</var> over whatever text should not be output normally.
 </p>
 <a name="index-recog_005fdata_002eoperand"></a>
 <p>If you need to look at the operand values, they can be found as the
 elements of <code>recog_data.operand</code>.
 </p>
 <p>If the macro definition does nothing, the instruction is output
 in the usual way.
 </p></dd></dl>

 <dl>
 <dt><a name="index-FINAL_005fPRESCAN_005fINSN"></a>Macro: <strong>FINAL_PRESCAN_INSN</strong> <em>(<var>insn</var>, <var>opvec</var>, <var>noperands</var>)</em></dt>
 <dd><p>If defined, a C statement to be executed just prior to the output of
 assembler code for <var>insn</var>, to modify the extracted operands so
 they will be output differently.
 </p>
 <p>Here the argument <var>opvec</var> is the vector containing the operands
 extracted from <var>insn</var>, and <var>noperands</var> is the number of
 elements of the vector which contain meaningful data for this insn.
 The contents of this vector are what will be used to convert the insn
 template into assembler code, so you can change the assembler output
 by changing the contents of the vector.
 </p>
 <p>This macro is useful when various assembler syntaxes share a single
 file of instruction patterns; by defining this macro differently, you
 can cause a large class of instructions to be output differently (such
 as with rearranged operands).  Naturally, variations in assembler
 syntax affecting individual insn patterns ought to be handled by
 writing conditional output routines in those patterns.
 </p>
 <p>If this macro is not defined, it is equivalent to a null statement.
 </p></dd></dl>

 <dl>
 <dt><a name="index-TARGET_005fASM_005fFINAL_005fPOSTSCAN_005fINSN"></a>Target Hook: <em>void</em> <strong>TARGET_ASM_FINAL_POSTSCAN_INSN</strong> <em>(FILE *<var>file</var>, rtx <var>insn</var>, rtx *<var>opvec</var>, int <var>noperands</var>)</em></dt>
 <dd><p>If defined, this target hook is a function which is executed just after the
 output of assembler code for <var>insn</var>, to change the mode of the assembler
 if necessary.
 </p>
 <p>Here the argument <var>opvec</var> is the vector containing the operands
 extracted from <var>insn</var>, and <var>noperands</var> is the number of
 elements of the vector which contain meaningful data for this insn.
 The contents of this vector are what was used to convert the insn
 template into assembler code, so you can change the assembler mode
 by checking the contents of the vector.
 </p></dd></dl>

 <dl>
 <dt><a name="index-PRINT_005fOPERAND"></a>Macro: <strong>PRINT_OPERAND</strong> <em>(<var>stream</var>, <var>x</var>, <var>code</var>)</em></dt>
 <dd><p>A C compound statement to output to stdio stream <var>stream</var> the
 assembler syntax for an instruction operand <var>x</var>.  <var>x</var> is an
 RTL expression.
 </p>
 <p><var>code</var> is a value that can be used to specify one of several ways
 of printing the operand.  It is used when identical operands must be
 printed differently depending on the context.  <var>code</var> comes from
 the &lsquo;<samp>%</samp>&rsquo; specification that was used to request printing of the
 operand.  If the specification was just &lsquo;<samp>%<var>digit</var></samp>&rsquo; then
 <var>code</var> is 0; if the specification was &lsquo;<samp>%<var>ltr</var>
 <var>digit</var></samp>&rsquo; then <var>code</var> is the ASCII code for <var>ltr</var>.
 </p>
 <a name="index-reg_005fnames-1"></a>
 <p>If <var>x</var> is a register, this macro should print the register&rsquo;s name.
 The names can be found in an array <code>reg_names</code> whose type is
 <code>char *[]</code>.  <code>reg_names</code> is initialized from
 <code>REGISTER_NAMES</code>.
 </p>
 <p>When the machine description has a specification &lsquo;<samp>%<var>punct</var></samp>&rsquo;
 (a &lsquo;<samp>%</samp>&rsquo; followed by a punctuation character), this macro is called
 with a null pointer for <var>x</var> and the punctuation character for
 <var>code</var>.
 </p></dd></dl>

 <dl>
 <dt><a name="index-PRINT_005fOPERAND_005fPUNCT_005fVALID_005fP"></a>Macro: <strong>PRINT_OPERAND_PUNCT_VALID_P</strong> <em>(<var>code</var>)</em></dt>
 <dd><p>A C expression which evaluates to true if <var>code</var> is a valid
 punctuation character for use in the <code>PRINT_OPERAND</code> macro.  If
 <code>PRINT_OPERAND_PUNCT_VALID_P</code> is not defined, it means that no
 punctuation characters (except for the standard one, &lsquo;<samp>%</samp>&rsquo;) are used
 in this way.
 </p></dd></dl>

 <dl>
 <dt><a name="index-PRINT_005fOPERAND_005fADDRESS"></a>Macro: <strong>PRINT_OPERAND_ADDRESS</strong> <em>(<var>stream</var>, <var>x</var>)</em></dt>
 <dd><p>A C compound statement to output to stdio stream <var>stream</var> the
 assembler syntax for an instruction operand that is a memory reference
 whose address is <var>x</var>.  <var>x</var> is an RTL expression.
 </p>
 <a name="index-TARGET_005fENCODE_005fSECTION_005fINFO-usage"></a>
 <p>On some machines, the syntax for a symbolic address depends on the
 section that the address refers to.  On these machines, define the hook
 <code>TARGET_ENCODE_SECTION_INFO</code> to store the information into the
 <code>symbol_ref</code>, and then check for it here.  See <a href="Assembler-Format.html#Assembler-Format">Assembler Format</a>.
 </p></dd></dl>

 <a name="index-dbr_005fsequence_005flength"></a>
 <dl>
 <dt><a name="index-DBR_005fOUTPUT_005fSEQEND"></a>Macro: <strong>DBR_OUTPUT_SEQEND</strong> <em>(<var>file</var>)</em></dt>
 <dd><p>A C statement, to be executed after all slot-filler instructions have
 been output.  If necessary, call <code>dbr_sequence_length</code> to
 determine the number of slots filled in a sequence (zero if not
 currently outputting a sequence), to decide how many no-ops to output,
 or whatever.
 </p>
 <p>Don&rsquo;t define this macro if it has nothing to do, but it is helpful in
 reading assembly output if the extent of the delay sequence is made
 explicit (e.g. with white space).
 </p></dd></dl>

 <a name="index-final_005fsequence"></a>
 <p>Note that output routines for instructions with delay slots must be
 prepared to deal with not being output as part of a sequence
 (i.e. when the scheduling pass is not run, or when no slot fillers could be
 found.)  The variable <code>final_sequence</code> is null when not
 processing a sequence, otherwise it contains the <code>sequence</code> rtx
 being output.
 </p>
 <a name="index-asm_005ffprintf"></a>
 <dl>
 <dt><a name="index-REGISTER_005fPREFIX"></a>Macro: <strong>REGISTER_PREFIX</strong></dt>
 <dt><a name="index-LOCAL_005fLABEL_005fPREFIX"></a>Macro: <strong>LOCAL_LABEL_PREFIX</strong></dt>
 <dt><a name="index-USER_005fLABEL_005fPREFIX"></a>Macro: <strong>USER_LABEL_PREFIX</strong></dt>
 <dt><a name="index-IMMEDIATE_005fPREFIX"></a>Macro: <strong>IMMEDIATE_PREFIX</strong></dt>
 <dd><p>If defined, C string expressions to be used for the &lsquo;<samp>%R</samp>&rsquo;, &lsquo;<samp>%L</samp>&rsquo;,
 &lsquo;<samp>%U</samp>&rsquo;, and &lsquo;<samp>%I</samp>&rsquo; options of <code>asm_fprintf</code> (see
 <samp>final.c</samp>).  These are useful when a single <samp>md</samp> file must
 support multiple assembler formats.  In that case, the various <samp>tm.h</samp>
 files can define these macros differently.
 </p></dd></dl>

 <dl>
 <dt><a name="index-ASM_005fFPRINTF_005fEXTENSIONS"></a>Macro: <strong>ASM_FPRINTF_EXTENSIONS</strong> <em>(<var>file</var>, <var>argptr</var>, <var>format</var>)</em></dt>
 <dd><p>If defined this macro should expand to a series of <code>case</code>
 statements which will be parsed inside the <code>switch</code> statement of
 the <code>asm_fprintf</code> function.  This allows targets to define extra
 printf formats which may useful when generating their assembler
 statements.  Note that uppercase letters are reserved for future
 generic extensions to asm_fprintf, and so are not available to target
 specific code.  The output file is given by the parameter <var>file</var>.
 The varargs input pointer is <var>argptr</var> and the rest of the format
 string, starting the character after the one that is being switched
 upon, is pointed to by <var>format</var>.
 </p></dd></dl>

 <dl>
 <dt><a name="index-ASSEMBLER_005fDIALECT"></a>Macro: <strong>ASSEMBLER_DIALECT</strong></dt>
 <dd><p>If your target supports multiple dialects of assembler language (such as
 different opcodes), define this macro as a C expression that gives the
 numeric index of the assembler language dialect to use, with zero as the
 first variant.
 </p>
 <p>If this macro is defined, you may use constructs of the form
 </p><div class="smallexample">
 <pre class="smallexample">&lsquo;<samp>{option0|option1|option2&hellip;}</samp>&rsquo;
 </pre></div>
 <p>in the output templates of patterns (see <a href="Output-Template.html#Output-Template">Output Template</a>) or in the
 first argument of <code>asm_fprintf</code>.  This construct outputs
 &lsquo;<samp>option0</samp>&rsquo;, &lsquo;<samp>option1</samp>&rsquo;, &lsquo;<samp>option2</samp>&rsquo;, etc., if the value of
 <code>ASSEMBLER_DIALECT</code> is zero, one, two, etc.  Any special characters
 within these strings retain their usual meaning.  If there are fewer
 alternatives within the braces than the value of
 <code>ASSEMBLER_DIALECT</code>, the construct outputs nothing. If it&rsquo;s needed
 to print curly braces or &lsquo;<samp>|</samp>&rsquo; character in assembler output directly,
 &lsquo;<samp>%{</samp>&rsquo;, &lsquo;<samp>%}</samp>&rsquo; and &lsquo;<samp>%|</samp>&rsquo; can be used.
 </p>
 <p>If you do not define this macro, the characters &lsquo;<samp>{</samp>&rsquo;, &lsquo;<samp>|</samp>&rsquo; and
 &lsquo;<samp>}</samp>&rsquo; do not have any special meaning when used in templates or
 operands to <code>asm_fprintf</code>.
 </p>
 <p>Define the macros <code>REGISTER_PREFIX</code>, <code>LOCAL_LABEL_PREFIX</code>,
 <code>USER_LABEL_PREFIX</code> and <code>IMMEDIATE_PREFIX</code> if you can express
 the variations in assembler language syntax with that mechanism.  Define
 <code>ASSEMBLER_DIALECT</code> and use the &lsquo;<samp>{option0|option1}</samp>&rsquo; syntax
 if the syntax variant are larger and involve such things as different
 opcodes or operand order.
 </p></dd></dl>

 <dl>
 <dt><a name="index-ASM_005fOUTPUT_005fREG_005fPUSH"></a>Macro: <strong>ASM_OUTPUT_REG_PUSH</strong> <em>(<var>stream</var>, <var>regno</var>)</em></dt>
 <dd><p>A C expression to output to <var>stream</var> some assembler code
 which will push hard register number <var>regno</var> onto the stack.
 The code need not be optimal, since this macro is used only when
 profiling.
 </p></dd></dl>

 <dl>
 <dt><a name="index-ASM_005fOUTPUT_005fREG_005fPOP"></a>Macro: <strong>ASM_OUTPUT_REG_POP</strong> <em>(<var>stream</var>, <var>regno</var>)</em></dt>
 <dd><p>A C expression to output to <var>stream</var> some assembler code
 which will pop hard register number <var>regno</var> off of the stack.
 The code need not be optimal, since this macro is used only when
 profiling.
 </p></dd></dl>

 <hr>
 <div class="header">
 <p>
 Next: <a href="Dispatch-Tables.html#Dispatch-Tables" accesskey="n" rel="next">Dispatch Tables</a>, Previous: <a href="Macros-for-Initialization.html#Macros-for-Initialization" accesskey="p" rel="prev">Macros for Initialization</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</a> &nbsp; [<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>
	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
	<html>
	<!-- Copyright (C) 1988-2015 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: Instruction Output</title>

	<meta name="description" content="GNU Compiler Collection (GCC) Internals: Instruction Output">
	<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Instruction Output">
	<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="Dispatch-Tables.html#Dispatch-Tables" rel="next" title="Dispatch Tables">
	<link href="Macros-for-Initialization.html#Macros-for-Initialization" rel="prev" title="Macros for Initialization">
	<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="Instruction-Output"></a>
	<div class="header">
	<p>
	Next: <a href="Dispatch-Tables.html#Dispatch-Tables" accesskey="n" rel="next">Dispatch Tables</a>, Previous: <a href="Macros-for-Initialization.html#Macros-for-Initialization" accesskey="p" rel="prev">Macros for Initialization</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-Assembler-Instructions"></a>
	<h4 class="subsection">17.21.7 Output of Assembler Instructions</h4>

	<p>This describes assembler instruction output.
	</p>
	<dl>
	<dt><a name="index-REGISTER_005fNAMES"></a>Macro: <strong>REGISTER_NAMES</strong></dt>
	<dd><p>A C initializer containing the assembler’s names for the machine
	registers, each one as a C string constant. This is what translates
	register numbers in the compiler into assembler language.
	</p></dd></dl>

	<dl>
	<dt><a name="index-ADDITIONAL_005fREGISTER_005fNAMES"></a>Macro: <strong>ADDITIONAL_REGISTER_NAMES</strong></dt>
	<dd><p>If defined, a C initializer for an array of structures containing a name
	and a register number. This macro defines additional names for hard
	registers, thus allowing the <code>asm</code> option in declarations to refer
	to registers using alternate names.
	</p></dd></dl>

	<dl>
	<dt><a name="index-OVERLAPPING_005fREGISTER_005fNAMES"></a>Macro: <strong>OVERLAPPING_REGISTER_NAMES</strong></dt>
	<dd><p>If defined, a C initializer for an array of structures containing a
	name, a register number and a count of the number of consecutive
	machine registers the name overlaps. This macro defines additional
	names for hard registers, thus allowing the <code>asm</code> option in
	declarations to refer to registers using alternate names. Unlike
	<code>ADDITIONAL_REGISTER_NAMES</code>, this macro should be used when the
	register name implies multiple underlying registers.
	</p>
	<p>This macro should be used when it is important that a clobber in an
	<code>asm</code> statement clobbers all the underlying values implied by the
	register name. For example, on ARM, clobbering the double-precision
	VFP register “d0” implies clobbering both single-precision registers
	“s0” and “s1”.
	</p></dd></dl>

	<dl>
	<dt><a name="index-ASM_005fOUTPUT_005fOPCODE"></a>Macro: <strong>ASM_OUTPUT_OPCODE</strong> <em>(<var>stream</var>, <var>ptr</var>)</em></dt>
	<dd><p>Define this macro if you are using an unusual assembler that
	requires different names for the machine instructions.
	</p>
	<p>The definition is a C statement or statements which output an
	assembler instruction opcode to the stdio stream <var>stream</var>. The
	macro-operand <var>ptr</var> is a variable of type <code>char *</code> which
	points to the opcode name in its “internal” form—the form that is
	written in the machine description. The definition should output the
	opcode name to <var>stream</var>, performing any translation you desire, and
	increment the variable <var>ptr</var> to point at the end of the opcode
	so that it will not be output twice.
	</p>
	<p>In fact, your macro definition may process less than the entire opcode
	name, or more than the opcode name; but if you want to process text
	that includes ‘<samp>%</samp>’-sequences to substitute operands, you must take
	care of the substitution yourself. Just be sure to increment
	<var>ptr</var> over whatever text should not be output normally.
	</p>
	<a name="index-recog_005fdata_002eoperand"></a>
	<p>If you need to look at the operand values, they can be found as the
	elements of <code>recog_data.operand</code>.
	</p>
	<p>If the macro definition does nothing, the instruction is output
	in the usual way.
	</p></dd></dl>

	<dl>
	<dt><a name="index-FINAL_005fPRESCAN_005fINSN"></a>Macro: <strong>FINAL_PRESCAN_INSN</strong> <em>(<var>insn</var>, <var>opvec</var>, <var>noperands</var>)</em></dt>
	<dd><p>If defined, a C statement to be executed just prior to the output of
	assembler code for <var>insn</var>, to modify the extracted operands so
	they will be output differently.
	</p>
	<p>Here the argument <var>opvec</var> is the vector containing the operands
	extracted from <var>insn</var>, and <var>noperands</var> is the number of
	elements of the vector which contain meaningful data for this insn.
	The contents of this vector are what will be used to convert the insn
	template into assembler code, so you can change the assembler output
	by changing the contents of the vector.
	</p>
	<p>This macro is useful when various assembler syntaxes share a single
	file of instruction patterns; by defining this macro differently, you
	can cause a large class of instructions to be output differently (such
	as with rearranged operands). Naturally, variations in assembler
	syntax affecting individual insn patterns ought to be handled by
	writing conditional output routines in those patterns.
	</p>
	<p>If this macro is not defined, it is equivalent to a null statement.
	</p></dd></dl>

	<dl>
	<dt><a name="index-TARGET_005fASM_005fFINAL_005fPOSTSCAN_005fINSN"></a>Target Hook: <em>void</em> <strong>TARGET_ASM_FINAL_POSTSCAN_INSN</strong> <em>(FILE <var>file</var>, rtx <var>insn</var>, rtx <var>opvec</var>, int <var>noperands</var>)</em></dt>
	<dd><p>If defined, this target hook is a function which is executed just after the
	output of assembler code for <var>insn</var>, to change the mode of the assembler
	if necessary.
	</p>
	<p>Here the argument <var>opvec</var> is the vector containing the operands
	extracted from <var>insn</var>, and <var>noperands</var> is the number of
	elements of the vector which contain meaningful data for this insn.
	The contents of this vector are what was used to convert the insn
	template into assembler code, so you can change the assembler mode
	by checking the contents of the vector.
	</p></dd></dl>

	<dl>
	<dt><a name="index-PRINT_005fOPERAND"></a>Macro: <strong>PRINT_OPERAND</strong> <em>(<var>stream</var>, <var>x</var>, <var>code</var>)</em></dt>
	<dd><p>A C compound statement to output to stdio stream <var>stream</var> the
	assembler syntax for an instruction operand <var>x</var>. <var>x</var> is an
	RTL expression.
	</p>
	<p><var>code</var> is a value that can be used to specify one of several ways
	of printing the operand. It is used when identical operands must be
	printed differently depending on the context. <var>code</var> comes from
	the ‘<samp>%</samp>’ specification that was used to request printing of the
	operand. If the specification was just ‘<samp>%<var>digit</var></samp>’ then
	<var>code</var> is 0; if the specification was ‘<samp>%<var>ltr</var>
	<var>digit</var></samp>’ then <var>code</var> is the ASCII code for <var>ltr</var>.
	</p>
	<a name="index-reg_005fnames-1"></a>
	<p>If <var>x</var> is a register, this macro should print the register’s name.
	The names can be found in an array <code>reg_names</code> whose type is
	<code>char *[]</code>. <code>reg_names</code> is initialized from
	<code>REGISTER_NAMES</code>.
	</p>
	<p>When the machine description has a specification ‘<samp>%<var>punct</var></samp>’
	(a ‘<samp>%</samp>’ followed by a punctuation character), this macro is called
	with a null pointer for <var>x</var> and the punctuation character for
	<var>code</var>.
	</p></dd></dl>

	<dl>
	<dt><a name="index-PRINT_005fOPERAND_005fPUNCT_005fVALID_005fP"></a>Macro: <strong>PRINT_OPERAND_PUNCT_VALID_P</strong> <em>(<var>code</var>)</em></dt>
	<dd><p>A C expression which evaluates to true if <var>code</var> is a valid
	punctuation character for use in the <code>PRINT_OPERAND</code> macro. If
	<code>PRINT_OPERAND_PUNCT_VALID_P</code> is not defined, it means that no
	punctuation characters (except for the standard one, ‘<samp>%</samp>’) are used
	in this way.
	</p></dd></dl>

	<dl>
	<dt><a name="index-PRINT_005fOPERAND_005fADDRESS"></a>Macro: <strong>PRINT_OPERAND_ADDRESS</strong> <em>(<var>stream</var>, <var>x</var>)</em></dt>
	<dd><p>A C compound statement to output to stdio stream <var>stream</var> the
	assembler syntax for an instruction operand that is a memory reference
	whose address is <var>x</var>. <var>x</var> is an RTL expression.
	</p>
	<a name="index-TARGET_005fENCODE_005fSECTION_005fINFO-usage"></a>
	<p>On some machines, the syntax for a symbolic address depends on the
	section that the address refers to. On these machines, define the hook
	<code>TARGET_ENCODE_SECTION_INFO</code> to store the information into the
	<code>symbol_ref</code>, and then check for it here. See <a href="Assembler-Format.html#Assembler-Format">Assembler Format</a>.
	</p></dd></dl>

	<a name="index-dbr_005fsequence_005flength"></a>
	<dl>
	<dt><a name="index-DBR_005fOUTPUT_005fSEQEND"></a>Macro: <strong>DBR_OUTPUT_SEQEND</strong> <em>(<var>file</var>)</em></dt>
	<dd><p>A C statement, to be executed after all slot-filler instructions have
	been output. If necessary, call <code>dbr_sequence_length</code> to
	determine the number of slots filled in a sequence (zero if not
	currently outputting a sequence), to decide how many no-ops to output,
	or whatever.
	</p>
	<p>Don’t define this macro if it has nothing to do, but it is helpful in
	reading assembly output if the extent of the delay sequence is made
	explicit (e.g. with white space).
	</p></dd></dl>

	<a name="index-final_005fsequence"></a>
	<p>Note that output routines for instructions with delay slots must be
	prepared to deal with not being output as part of a sequence
	(i.e. when the scheduling pass is not run, or when no slot fillers could be
	found.) The variable <code>final_sequence</code> is null when not
	processing a sequence, otherwise it contains the <code>sequence</code> rtx
	being output.
	</p>
	<a name="index-asm_005ffprintf"></a>
	<dl>
	<dt><a name="index-REGISTER_005fPREFIX"></a>Macro: <strong>REGISTER_PREFIX</strong></dt>
	<dt><a name="index-LOCAL_005fLABEL_005fPREFIX"></a>Macro: <strong>LOCAL_LABEL_PREFIX</strong></dt>
	<dt><a name="index-USER_005fLABEL_005fPREFIX"></a>Macro: <strong>USER_LABEL_PREFIX</strong></dt>
	<dt><a name="index-IMMEDIATE_005fPREFIX"></a>Macro: <strong>IMMEDIATE_PREFIX</strong></dt>
	<dd><p>If defined, C string expressions to be used for the ‘<samp>%R</samp>’, ‘<samp>%L</samp>’,
	‘<samp>%U</samp>’, and ‘<samp>%I</samp>’ options of <code>asm_fprintf</code> (see
	<samp>final.c</samp>). These are useful when a single <samp>md</samp> file must
	support multiple assembler formats. In that case, the various <samp>tm.h</samp>
	files can define these macros differently.
	</p></dd></dl>

	<dl>
	<dt><a name="index-ASM_005fFPRINTF_005fEXTENSIONS"></a>Macro: <strong>ASM_FPRINTF_EXTENSIONS</strong> <em>(<var>file</var>, <var>argptr</var>, <var>format</var>)</em></dt>
	<dd><p>If defined this macro should expand to a series of <code>case</code>
	statements which will be parsed inside the <code>switch</code> statement of
	the <code>asm_fprintf</code> function. This allows targets to define extra
	printf formats which may useful when generating their assembler
	statements. Note that uppercase letters are reserved for future
	generic extensions to asm_fprintf, and so are not available to target
	specific code. The output file is given by the parameter <var>file</var>.
	The varargs input pointer is <var>argptr</var> and the rest of the format
	string, starting the character after the one that is being switched
	upon, is pointed to by <var>format</var>.
	</p></dd></dl>

	<dl>
	<dt><a name="index-ASSEMBLER_005fDIALECT"></a>Macro: <strong>ASSEMBLER_DIALECT</strong></dt>
	<dd><p>If your target supports multiple dialects of assembler language (such as
	different opcodes), define this macro as a C expression that gives the
	numeric index of the assembler language dialect to use, with zero as the
	first variant.
	</p>
	<p>If this macro is defined, you may use constructs of the form
	</p><div class="smallexample">
	<pre class="smallexample">‘<samp>{option0\|option1\|option2…}</samp>’
	</pre></div>
	<p>in the output templates of patterns (see <a href="Output-Template.html#Output-Template">Output Template</a>) or in the
	first argument of <code>asm_fprintf</code>. This construct outputs
	‘<samp>option0</samp>’, ‘<samp>option1</samp>’, ‘<samp>option2</samp>’, etc., if the value of
	<code>ASSEMBLER_DIALECT</code> is zero, one, two, etc. Any special characters
	within these strings retain their usual meaning. If there are fewer
	alternatives within the braces than the value of
	<code>ASSEMBLER_DIALECT</code>, the construct outputs nothing. If it’s needed
	to print curly braces or ‘<samp>\|</samp>’ character in assembler output directly,
	‘<samp>%{</samp>’, ‘<samp>%}</samp>’ and ‘<samp>%\|</samp>’ can be used.
	</p>
	<p>If you do not define this macro, the characters ‘<samp>{</samp>’, ‘<samp>\|</samp>’ and
	‘<samp>}</samp>’ do not have any special meaning when used in templates or
	operands to <code>asm_fprintf</code>.
	</p>
	<p>Define the macros <code>REGISTER_PREFIX</code>, <code>LOCAL_LABEL_PREFIX</code>,
	<code>USER_LABEL_PREFIX</code> and <code>IMMEDIATE_PREFIX</code> if you can express
	the variations in assembler language syntax with that mechanism. Define
	<code>ASSEMBLER_DIALECT</code> and use the ‘<samp>{option0\|option1}</samp>’ syntax
	if the syntax variant are larger and involve such things as different
	opcodes or operand order.
	</p></dd></dl>

	<dl>
	<dt><a name="index-ASM_005fOUTPUT_005fREG_005fPUSH"></a>Macro: <strong>ASM_OUTPUT_REG_PUSH</strong> <em>(<var>stream</var>, <var>regno</var>)</em></dt>
	<dd><p>A C expression to output to <var>stream</var> some assembler code
	which will push hard register number <var>regno</var> onto the stack.
	The code need not be optimal, since this macro is used only when
	profiling.
	</p></dd></dl>

	<dl>
	<dt><a name="index-ASM_005fOUTPUT_005fREG_005fPOP"></a>Macro: <strong>ASM_OUTPUT_REG_POP</strong> <em>(<var>stream</var>, <var>regno</var>)</em></dt>
	<dd><p>A C expression to output to <var>stream</var> some assembler code
	which will pop hard register number <var>regno</var> off of the stack.
	The code need not be optimal, since this macro is used only when
	profiling.
	</p></dd></dl>

	<hr>
	<div class="header">
	<p>
	Next: <a href="Dispatch-Tables.html#Dispatch-Tables" accesskey="n" rel="next">Dispatch Tables</a>, Previous: <a href="Macros-for-Initialization.html#Macros-for-Initialization" accesskey="p" rel="prev">Macros for Initialization</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>