221 lines
8.8 KiB
XML
221 lines
8.8 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
|
|
<?xml-stylesheet type="text/xsl" encoding="UTF-8" href="iform.xsl" version="1.0"?>
|
|
<!DOCTYPE instructionsection PUBLIC "-//ARM//DTD instructionsection //EN" "iform-p.dtd">
|
|
<!-- Copyright (c) 2010-2022 Arm Limited or its affiliates. All rights reserved. -->
|
|
<!-- This document is Non-Confidential. This document may only be used and distributed in accordance with the terms of the agreement entered into by Arm and the party that Arm delivered this document to. -->
|
|
|
|
<instructionsection id="CLRBHB" title="CLRBHB -- AArch32" type="instruction">
|
|
<docvars>
|
|
<docvar key="instr-class" value="general" />
|
|
<docvar key="mnemonic" value="CLRBHB" />
|
|
</docvars>
|
|
<heading>CLRBHB</heading>
|
|
<desc>
|
|
<brief>
|
|
<para>Clear Branch History</para>
|
|
</brief>
|
|
<authored>
|
|
<para>Clear Branch History clears the branch history for the current context to the extent that branch history information created before the <instruction>CLRBHB</instruction> instruction cannot be used by code before the <instruction>CLRBHB</instruction> instruction to exploitatively control the execution of any indirect branches in code in the current context that appear in program order after the instruction.</para>
|
|
</authored>
|
|
</desc>
|
|
<alias_list howmany="0"></alias_list>
|
|
<classes>
|
|
<classesintro count="2">
|
|
<txt>It has encodings from the following instruction sets:</txt>
|
|
<txt> A32 (</txt>
|
|
<a href="#iclass_a1">A1</a>
|
|
<txt>)</txt>
|
|
<txt> and </txt>
|
|
<txt> T32 (</txt>
|
|
<a href="#iclass_t1">T1</a>
|
|
<txt>)</txt>
|
|
<txt>.</txt>
|
|
</classesintro>
|
|
<iclass name="A1" oneof="2" id="iclass_a1" no_encodings="1" isa="A32">
|
|
<docvars>
|
|
<docvar key="armarmheading" value="A1" />
|
|
<docvar key="instr-class" value="general" />
|
|
<docvar key="isa" value="A32" />
|
|
<docvar key="mnemonic" value="CLRBHB" />
|
|
</docvars>
|
|
<iclassintro count="1"></iclassintro>
|
|
<arch_variants>
|
|
<arch_variant name="ARMv8.9" feature="FEAT_CLRBHB" />
|
|
</arch_variants>
|
|
<regdiagram form="32" psname="aarch32/instrs/CLRBHB/A1_A.txt" tworows="1">
|
|
<box hibit="31" width="4" name="cond" usename="1" settings="4" constraint="!= 1111">
|
|
<c colspan="4">!= 1111</c>
|
|
</box>
|
|
<box hibit="27" width="5" settings="5">
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>1</c>
|
|
<c>1</c>
|
|
<c>0</c>
|
|
</box>
|
|
<box hibit="22" name="R" settings="1">
|
|
<c>0</c>
|
|
</box>
|
|
<box hibit="21" width="2" settings="2">
|
|
<c>1</c>
|
|
<c>0</c>
|
|
</box>
|
|
<box hibit="19" width="4" name="imm4" settings="4">
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>0</c>
|
|
</box>
|
|
<box hibit="15" settings="1">
|
|
<c>(1)</c>
|
|
</box>
|
|
<box hibit="14" settings="1">
|
|
<c>(1)</c>
|
|
</box>
|
|
<box hibit="13" settings="1">
|
|
<c>(1)</c>
|
|
</box>
|
|
<box hibit="12" settings="1">
|
|
<c>(1)</c>
|
|
</box>
|
|
<box hibit="11" width="12" name="imm12" settings="12">
|
|
<c>(0)</c>
|
|
<c>(0)</c>
|
|
<c>(0)</c>
|
|
<c>(0)</c>
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>1</c>
|
|
<c>0</c>
|
|
<c>1</c>
|
|
<c>1</c>
|
|
<c>0</c>
|
|
</box>
|
|
</regdiagram>
|
|
<encoding name="CLRBHB_A1" oneofinclass="1" oneof="2" label="A1">
|
|
<docvars>
|
|
<docvar key="armarmheading" value="A1" />
|
|
<docvar key="instr-class" value="general" />
|
|
<docvar key="isa" value="A32" />
|
|
<docvar key="mnemonic" value="CLRBHB" />
|
|
</docvars>
|
|
<asmtemplate><text>CLRBHB</text><text>{</text><a link="sa_c" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}"><c></a><text>}</text><text>{</text><a link="sa_q" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}"><q></a><text>}</text></asmtemplate>
|
|
</encoding>
|
|
<ps_section howmany="1">
|
|
<ps name="aarch32/instrs/CLRBHB/A1_A.txt" mylink="aarch32.instrs.CLRBHB.A1_A.txt" enclabels="" sections="1" secttype="noheading">
|
|
<pstext mayhavelinks="1" section="Decode" rep_section="decode">if !<a link="impl-shared.HaveFeatCLRBHB.0" file="shared_pseudocode.xml" hover="function: boolean HaveFeatCLRBHB()">HaveFeatCLRBHB</a>() then <a link="impl-shared.EndOfInstruction.0" file="shared_pseudocode.xml" hover="function: EndOfInstruction()">EndOfInstruction</a>(); // Instruction executes as NOP</pstext>
|
|
</ps>
|
|
</ps_section>
|
|
</iclass>
|
|
<iclass name="T1" oneof="2" id="iclass_t1" no_encodings="1" isa="T32">
|
|
<docvars>
|
|
<docvar key="armarmheading" value="T1" />
|
|
<docvar key="instr-class" value="general" />
|
|
<docvar key="isa" value="T32" />
|
|
<docvar key="mnemonic" value="CLRBHB" />
|
|
</docvars>
|
|
<iclassintro count="1"></iclassintro>
|
|
<arch_variants>
|
|
<arch_variant name="ARMv8.9" feature="FEAT_CLRBHB" />
|
|
</arch_variants>
|
|
<regdiagram form="16x2" psname="aarch32/instrs/CLRBHB/T1_A.txt">
|
|
<box hibit="31" width="12" settings="12">
|
|
<c>1</c>
|
|
<c>1</c>
|
|
<c>1</c>
|
|
<c>1</c>
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>1</c>
|
|
<c>1</c>
|
|
<c>1</c>
|
|
<c>0</c>
|
|
<c>1</c>
|
|
<c>0</c>
|
|
</box>
|
|
<box hibit="19" settings="1">
|
|
<c>(1)</c>
|
|
</box>
|
|
<box hibit="18" settings="1">
|
|
<c>(1)</c>
|
|
</box>
|
|
<box hibit="17" settings="1">
|
|
<c>(1)</c>
|
|
</box>
|
|
<box hibit="16" settings="1">
|
|
<c>(1)</c>
|
|
</box>
|
|
<box hibit="15" width="2" settings="2">
|
|
<c>1</c>
|
|
<c>0</c>
|
|
</box>
|
|
<box hibit="13" settings="1">
|
|
<c>(0)</c>
|
|
</box>
|
|
<box hibit="12" settings="1">
|
|
<c>0</c>
|
|
</box>
|
|
<box hibit="11" settings="1">
|
|
<c>(0)</c>
|
|
</box>
|
|
<box hibit="10" width="3" settings="3">
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>0</c>
|
|
</box>
|
|
<box hibit="7" width="4" name="hint" settings="4">
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>0</c>
|
|
<c>1</c>
|
|
</box>
|
|
<box hibit="3" width="4" name="option" settings="4">
|
|
<c>0</c>
|
|
<c>1</c>
|
|
<c>1</c>
|
|
<c>0</c>
|
|
</box>
|
|
</regdiagram>
|
|
<encoding name="CLRBHB_T1" oneofinclass="1" oneof="2" label="T1">
|
|
<docvars>
|
|
<docvar key="armarmheading" value="T1" />
|
|
<docvar key="instr-class" value="general" />
|
|
<docvar key="isa" value="T32" />
|
|
<docvar key="mnemonic" value="CLRBHB" />
|
|
</docvars>
|
|
<asmtemplate><text>CLRBHB</text><text>{</text><a link="sa_c" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}"><c></a><text>}</text><text>{</text><a link="sa_q" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}"><q></a><text>}</text></asmtemplate>
|
|
</encoding>
|
|
<ps_section howmany="1">
|
|
<ps name="aarch32/instrs/CLRBHB/T1_A.txt" mylink="aarch32.instrs.CLRBHB.T1_A.txt" enclabels="" sections="1" secttype="noheading">
|
|
<pstext mayhavelinks="1" section="Decode" rep_section="decode">if !<a link="impl-shared.HaveFeatCLRBHB.0" file="shared_pseudocode.xml" hover="function: boolean HaveFeatCLRBHB()">HaveFeatCLRBHB</a>() then <a link="impl-shared.EndOfInstruction.0" file="shared_pseudocode.xml" hover="function: EndOfInstruction()">EndOfInstruction</a>(); // Instruction executes as NOP</pstext>
|
|
</ps>
|
|
</ps_section>
|
|
</iclass>
|
|
</classes>
|
|
<explanations scope="all">
|
|
<explanation enclist="CLRBHB_A1, CLRBHB_T1" symboldefcount="1">
|
|
<symbol link="sa_c"><c></symbol>
|
|
<account encodedin="">
|
|
<intro>
|
|
<para>See <xref linkend="Babbefhf">Standard assembler syntax fields</xref>.</para>
|
|
</intro>
|
|
</account>
|
|
</explanation>
|
|
<explanation enclist="CLRBHB_A1, CLRBHB_T1" symboldefcount="1">
|
|
<symbol link="sa_q"><q></symbol>
|
|
<account encodedin="">
|
|
<intro>
|
|
<para>See <xref linkend="Babbefhf">Standard assembler syntax fields</xref>.</para>
|
|
</intro>
|
|
</account>
|
|
</explanation>
|
|
</explanations>
|
|
<ps_section howmany="1">
|
|
<ps name="aarch32/instrs/CLRBHB/Op_A.txt" mylink="execute" enclabels="" sections="1" secttype="Operation">
|
|
<pstext mayhavelinks="1" section="Execute" rep_section="execute">if <a link="impl-aarch32.ConditionPassed.0" file="shared_pseudocode.xml" hover="function: boolean ConditionPassed()">ConditionPassed</a>() then
|
|
EncodingSpecificOperations();
|
|
<a link="impl-shared.Hint_CLRBHB.0" file="shared_pseudocode.xml" hover="function: Hint_CLRBHB()">Hint_CLRBHB</a>();</pstext>
|
|
</ps>
|
|
</ps_section>
|
|
</instructionsection>
|