| <!-- Copyright (c) 2010-2025 Arm Limited or its affiliates. All rights reserved. --> |
| <!-- This document is Non-confidential and licensed under the BSD 3-clause license. --> |
| <!DOCTYPE html> |
| <html> |
| <head> |
| <meta charset="utf-8" /> |
| <meta name="viewport" content="width=device-width, initial-scale=1"> |
| <meta http-equiv="x-ua-compatible" content="ie=edge"> |
| |
| <!--FAVICON.ico--> |
| <meta name="msapplication-TileColor" content="#2b5797"> |
| <meta name="msapplication-TileImage" content="../img/mstile-144x144.png"> |
| <link rel="icon" href="../img/favicon.ico"> |
| |
| <title>Instruction.InstructionAlias - ARM Machine Readable Schema - 2.6.3</title> |
| |
| <!--CSS--> |
| <link rel="stylesheet" type="text/css" href="../css/bootstrap.min.css"> |
| <link rel="stylesheet" type="text/css" href="../css/schema.css"> |
| <link rel="stylesheet" type="text/css" href="../css/hljs-github.css"> |
| </head> |
| <body> |
| <div class="container"> |
| <div class="row heading"> |
| <div class="col-md-6 pull-left"><a href="../index.html"><img src="../img/arm.svg" class="logo" /></a></div> |
| <div class="col-md-6 pull-left"><h1>AARCHMRS Schema <small>2.6.3</small></h1></div> |
| |
| <!--Show the home button--> |
| <a href="../index.html"><div class="back-to-home">↚ Home</div></a> |
| </div> |
| </div> |
| |
| <div class="container"> |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| <div class="row"> |
| |
| |
| |
| |
| <h2> |
| <span class="title-namespace">Instruction.</span><span class=" title-type">InstructionAlias</span> |
| |
| <!-- if oneOf is set, then type is ignored --> |
| <span class="type">object</span> |
| </h2> |
| |
| |
| |
| |
| <div class="static-markdown"><p>An <a class="schema_link" href="../Instruction/InstructionAlias_schema.html" title="Instruction.InstructionAlias">InstructionAlias</a> object defines an alias of an <a class="schema_link" href="../Instruction/Instruction_schema.html" title="Instruction.Instruction">Instruction</a> as a child of |
| that instruction. The alias assembly can be different, but the assembly it defines maps back to the assembly |
| of its parent <a class="schema_link" href="../Instruction/Instruction_schema.html" title="Instruction.Instruction">Instruction</a>.</p> |
| <p>The <code>operation_id</code> refers to an instance of <code>OperationAlias</code>, which provides a link to the ASL pseudocode |
| for the alias and overrides the descriptive elements.</p> |
| <p>The <code>preferred</code> attribute states when a disassembler should emit the alias instead of the parent instruction. |
| It is a condition that evaluates True when the alias |
| should be emitted and False when the parent instruction should be emitted.</p> |
| <p>The first example below is of an alias named 'ADC32'. Its assembly is never preferred.</p> |
| <p>The second example has a <code>preferred</code> attribute. Its assembly is preferred if and only if FEAT_ADC is implemented |
| (otherwise, its parent is the preferred disassembly).</p></div> |
| </div> |
| |
| |
| |
| |
| |
| |
| <div class="row"> |
| |
| <div> |
| <!-- A simple object --> |
| <h3 class="type">object</h3> |
| |
| <table class="table table-hover properties"> |
| <thead> |
| <tr> |
| <th class="col-md-4">Properties</th> |
| <th class="col-md-4">Type</th> |
| <th class="col-md-4">Description</th> |
| </tr> |
| </thead> |
| <tbody> |
| |
| <!-- properties --> |
| |
| |
| <tr id="/properties/_meta" class="property"> |
| <th class="col-md-4"> |
| <a href="#/properties/_meta">_meta</a> |
| </th> |
| <td class="col-md-4"> |
| <a href="../Meta_schema.html" class="schema_link">Meta</a> |
| </td> |
| <td class="col-md-4"> |
| <div><p>Metadata</p></div> |
| |
| <div> |
| See |
| <a href="../Meta_schema.html" class="schema_link">Meta</a> |
| for more information. |
| </div> |
| |
| |
| |
| |
| </td> |
| </tr> |
| |
| <tr id="/properties/_type" class="property"> |
| <th class="col-md-4"> |
| <a href="#/properties/_type">_type</a> |
| </th> |
| <td class="col-md-4"> |
| </td> |
| <td class="col-md-4"> |
| <dl> |
| <dt>Enum</dt> |
| <dd> |
| <code>Instruction.InstructionAlias</code> |
| </dd> |
| </dl> |
| |
| |
| |
| </td> |
| </tr> |
| |
| <tr id="/properties/assembly" class="property"> |
| <th class="col-md-4"> |
| <a href="#/properties/assembly">assembly<sup>◊</sup></a> |
| </th> |
| <td class="col-md-4"> |
| <a href="Assembly_schema.html" class="schema_link">Assembly</a> |
| </td> |
| <td class="col-md-4"> |
| <div><p>The assembly for this <a class="schema_link" href="../Instruction/InstructionAlias_schema.html" title="Instruction.InstructionAlias">InstructionAlias</a>.</p></div> |
| |
| <div> |
| See |
| <a href="Assembly_schema.html" class="schema_link">Assembly</a> |
| for more information. |
| </div> |
| |
| |
| |
| |
| </td> |
| </tr> |
| |
| <tr id="/properties/condition" class="property"> |
| <th class="col-md-4"> |
| <a href="#/properties/condition">condition</a> |
| </th> |
| <td class="col-md-4"> |
| <a href="../Traits/HasCondition_schema.html#/definitions/condition" class="schema_link">Traits.HasCondition</a> |
| </td> |
| <td class="col-md-4"> |
| |
| <div> |
| See |
| <a href="../Traits/HasCondition_schema.html#/definitions/condition" class="schema_link">definitions.condition</a> in |
| <a href="../Traits/HasCondition_schema.html#/definitions/condition" class="schema_link">Traits.HasCondition</a> |
| for more information. |
| </div> |
| |
| |
| |
| |
| </td> |
| </tr> |
| |
| <tr id="/properties/name" class="property"> |
| <th class="col-md-4"> |
| <a href="#/properties/name">name<sup>◊</sup></a> |
| </th> |
| <td class="col-md-4"> |
| <a href="../AST/Identifier_schema.html#/definitions/c_identifier_regex" class="schema_link">AST.Identifier</a> |
| </td> |
| <td class="col-md-4"> |
| <div><p>The unique name of the <a class="schema_link" href="../Instruction/InstructionAlias_schema.html" title="Instruction.InstructionAlias">InstructionAlias</a>, which identifies it in the instruction set.</p></div> |
| |
| <div> |
| See |
| <a href="../AST/Identifier_schema.html#/definitions/c_identifier_regex" class="schema_link">definitions.c_identifier_regex</a> in |
| <a href="../AST/Identifier_schema.html#/definitions/c_identifier_regex" class="schema_link">AST.Identifier</a> |
| for more information. |
| </div> |
| |
| |
| |
| |
| </td> |
| </tr> |
| |
| <tr id="/properties/operation_id" class="property"> |
| <th class="col-md-4"> |
| <a href="#/properties/operation_id">operation_id<sup>◊</sup></a> |
| </th> |
| <td class="col-md-4"> |
| <a href="../AST/Identifier_schema.html#/definitions/c_identifier_regex" class="schema_link">AST.Identifier</a> |
| </td> |
| <td class="col-md-4"> |
| <div><p>The ID of the <a class="schema_link" href="../Instruction/OperationAlias_schema.html" title="Instruction.OperationAlias">OperationAlias</a> for this <a class="schema_link" href="../Instruction/InstructionAlias_schema.html" title="Instruction.InstructionAlias">InstructionAlias</a>. The <a class="schema_link" href="../Instruction/OperationAlias_schema.html" title="Instruction.OperationAlias">OperationAlias</a> |
| is a value in the <code>operations</code> property of the top-level <a class="schema_link" href="../Instruction/Instructions_schema.html" title="Instruction.Instructions">Instructions</a> element, and this <code>operation_id</code> matches its key.</p></div> |
| |
| <div> |
| See |
| <a href="../AST/Identifier_schema.html#/definitions/c_identifier_regex" class="schema_link">definitions.c_identifier_regex</a> in |
| <a href="../AST/Identifier_schema.html#/definitions/c_identifier_regex" class="schema_link">AST.Identifier</a> |
| for more information. |
| </div> |
| |
| |
| |
| |
| </td> |
| </tr> |
| |
| <tr id="/properties/preferred" class="property"> |
| <th class="col-md-4"> |
| <a href="#/properties/preferred">preferred</a> |
| </th> |
| <td class="col-md-4"> |
| <a href="../Traits/HasCondition_schema.html#/definitions/condition" class="schema_link">Traits.HasCondition</a> |
| </td> |
| <td class="col-md-4"> |
| <div><p>Defines whether this <a class="schema_link" href="../Instruction/InstructionAlias_schema.html" title="Instruction.InstructionAlias">InstructionAlias</a> is the preferred disassembly for the parent <a class="schema_link" href="../Instruction/Instruction_schema.html" title="Instruction.Instruction">Instruction</a>. |
| If the <code>preferred</code> condition evaluates True, this <a class="schema_link" href="../Instruction/InstructionAlias_schema.html" title="Instruction.InstructionAlias">InstructionAlias</a> is the preferred disassembly. |
| This can be a complex condition that needs to be evaluated.</p></div> |
| |
| <div> |
| See |
| <a href="../Traits/HasCondition_schema.html#/definitions/condition" class="schema_link">definitions.condition</a> in |
| <a href="../Traits/HasCondition_schema.html#/definitions/condition" class="schema_link">Traits.HasCondition</a> |
| for more information. |
| </div> |
| |
| <div> |
| <b>Default</b> |
| <pre class="schema-json"><code class="language-json">{ |
| "_type": "AST.Bool", |
| "value": false |
| }</code></pre> |
| </div> |
| |
| |
| |
| </td> |
| </tr> |
| |
| |
| <!-- patternProperties --> |
| |
| <!-- object property attributes --> |
| <tr> |
| <td colspan="3"> |
| <dl> |
| <dt>Additional Properties</dt> |
| <dd>Not Allowed</dd> |
| </dl> |
| </td> |
| </tr> |
| |
| <tr> |
| <td colspan="3"> |
| <dl> |
| <dt>◊ Required</dt> |
| <dd>Properties marked with ◊ are required properties.</dd> |
| </dl> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| |
| |
| |
| |
| <!-- array, and it has described items --> |
| </div> |
| |
| |
| <h5>Examples</h5> |
| <div> |
| <pre class="schema-json"><code class="language-json">{ |
| "_type": "Instruction.InstructionAlias", |
| "name": "ADC32", |
| "operation_id": "foo", |
| "assembly": { |
| "_type": "Instruction.Assembly", |
| "symbols": [ |
| { |
| "_type": "Instruction.Symbols.Literal", |
| "value": "ADD" |
| }, |
| { |
| "_type": "Instruction.Symbols.RuleReference", |
| "rule_id": "Rd" |
| }, |
| { |
| "_type": "Instruction.Symbols.RuleReference", |
| "rule_id": "imm4" |
| } |
| ] |
| } |
| }</code></pre> |
| <pre class="schema-json"><code class="language-json">{ |
| "_type": "Instruction.InstructionAlias", |
| "name": "ADC32", |
| "operation_id": "foo", |
| "assembly": { |
| "_type": "Instruction.Assembly", |
| "symbols": [ |
| { |
| "_type": "Instruction.Symbols.Literal", |
| "value": "ADD" |
| }, |
| { |
| "_type": "Instruction.Symbols.RuleReference", |
| "rule_id": "Rd" |
| }, |
| { |
| "_type": "Instruction.Symbols.RuleReference", |
| "rule_id": "imm4" |
| } |
| ] |
| }, |
| "preferred": { |
| "_type": "AST.Function", |
| "arguments": [ |
| { |
| "_type": "AST.Identifier", |
| "value": "FEAT_ADC" |
| } |
| ], |
| "name": "IsFeatureImplemented" |
| } |
| }</code></pre> |
| </div> |
| |
| |
| |
| |
| </div> |
| |
| <div class="row schema"> |
| <h3>Schema <small><a href="http://json-schema.org/draft-04/schema#">http://json-schema.org/draft-04/schema#</a></small></h3> |
| <pre class="schema-json"><code class="language-json">{ |
| "type": "object", |
| "info": [ |
| [ |
| "An $(~Instruction.InstructionAlias) object defines an alias of an $(~Instruction.Instruction) as a child of", |
| "that instruction. The alias assembly can be different, but the assembly it defines maps back to the assembly", |
| "of its parent $(~Instruction.Instruction)." |
| ], |
| [ |
| "The `operation_id` refers to an instance of `OperationAlias`, which provides a link to the ASL pseudocode", |
| "for the alias and overrides the descriptive elements." |
| ], |
| [ |
| "The `preferred` attribute states when a disassembler should emit the alias instead of the parent instruction.", |
| "It is a condition that evaluates True when the alias", |
| "should be emitted and False when the parent instruction should be emitted." |
| ], |
| "The first example below is of an alias named 'ADC32'. Its assembly is never preferred.", |
| [ |
| "The second example has a `preferred` attribute. Its assembly is preferred if and only if FEAT_ADC is implemented", |
| "(otherwise, its parent is the preferred disassembly)." |
| ] |
| ], |
| "examples": [ |
| { |
| "_type": "Instruction.InstructionAlias", |
| "name": "ADC32", |
| "operation_id": "foo", |
| "assembly": { |
| "_type": "Instruction.Assembly", |
| "symbols": [ |
| { |
| "_type": "Instruction.Symbols.Literal", |
| "value": "ADD" |
| }, |
| { |
| "_type": "Instruction.Symbols.RuleReference", |
| "rule_id": "Rd" |
| }, |
| { |
| "_type": "Instruction.Symbols.RuleReference", |
| "rule_id": "imm4" |
| } |
| ] |
| } |
| }, |
| { |
| "_type": "Instruction.InstructionAlias", |
| "name": "ADC32", |
| "operation_id": "foo", |
| "assembly": { |
| "_type": "Instruction.Assembly", |
| "symbols": [ |
| { |
| "_type": "Instruction.Symbols.Literal", |
| "value": "ADD" |
| }, |
| { |
| "_type": "Instruction.Symbols.RuleReference", |
| "rule_id": "Rd" |
| }, |
| { |
| "_type": "Instruction.Symbols.RuleReference", |
| "rule_id": "imm4" |
| } |
| ] |
| }, |
| "preferred": { |
| "_type": "AST.Function", |
| "arguments": [ |
| { |
| "_type": "AST.Identifier", |
| "value": "FEAT_ADC" |
| } |
| ], |
| "name": "IsFeatureImplemented" |
| } |
| } |
| ], |
| "properties": { |
| "_meta": { |
| "$ref": "../Meta.json", |
| "info": [ |
| "Metadata" |
| ] |
| }, |
| "_type": { |
| "enum": [ |
| "Instruction.InstructionAlias" |
| ] |
| }, |
| "name": { |
| "info": [ |
| "The unique name of the $(~Instruction.InstructionAlias), which identifies it in the instruction set." |
| ], |
| "$ref": "../AST/Identifier.json#/definitions/c_identifier_regex" |
| }, |
| "operation_id": { |
| "info": [ |
| [ |
| "The ID of the $(~Instruction.OperationAlias) for this $(~Instruction.InstructionAlias). The $(~Instruction.OperationAlias)", |
| "is a value in the `operations` property of the top-level $(~Instruction.Instructions) element, and this `operation_id` matches its key." |
| ] |
| ], |
| "$ref": "../AST/Identifier.json#/definitions/c_identifier_regex" |
| }, |
| "assembly": { |
| "info": [ |
| "The assembly for this $(~Instruction.InstructionAlias)." |
| ], |
| "$ref": "Assembly.json" |
| }, |
| "preferred": { |
| "info": [ |
| [ |
| "Defines whether this $(~Instruction.InstructionAlias) is the preferred disassembly for the parent $(~Instruction.Instruction).", |
| "If the `preferred` condition evaluates True, this $(~Instruction.InstructionAlias) is the preferred disassembly.", |
| "This can be a complex condition that needs to be evaluated." |
| ] |
| ], |
| "$ref": "../Traits/HasCondition.json#/definitions/condition", |
| "default": { |
| "_type": "AST.Bool", |
| "value": false |
| } |
| }, |
| "condition": { |
| "$ref": "../Traits/HasCondition.json#/definitions/condition" |
| } |
| }, |
| "required": [ |
| "name", |
| "operation_id", |
| "assembly" |
| ], |
| "additionalProperties": false, |
| "$schema": "http://json-schema.org/draft-04/schema#", |
| "title": "Instruction.InstructionAlias" |
| }</code></pre> |
| </div> |
| |
| </div> |
| |
| <div class="container"> |
| <div class="footer text-right"> |
| Copyright © 2025 ARM Limited or its affiliates. All rights reserved. |
| </div> |
| </div> |
| |
| <script src="../js/highlight/highlight.js"></script> |
| <script src="../js/highlight/languages/json.min.js"></script> |
| <script src="../js/highlight/languages/django.min.js"></script> <!-- JINJA2 --> |
| <script src="../js/highlight/languages/yaml.min.js"></script> |
| <script src="../js/highlight/languages/isa.js"></script> |
| <script type="text/javascript"> |
| window.onload = function() { |
| hljs.configure({ |
| cssSelector: ".schema-json code, .includes code, pre code", |
| noHighlightRe: /^(no-?highlight|nohl)$/i, |
| }); |
| hljs.highlightAll() |
| }; |
| </script> |
| |
| </body> |
| </html> |