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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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diff --git a/share/doc/gccint/Instruction-Output.html b/share/doc/gccint/Instruction-Output.html new file mode 100644 index 0000000..cc1b511 --- /dev/null +++ b/share/doc/gccint/Instruction-Output.html @@ -0,0 +1,334 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 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 5.1, 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="previous" 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="previous">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">18.20.7 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_insn *<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.cc</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="previous">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> |