slonik/specs/fldmx.xml

367 lines
22 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="FLDMX" title="FLDM*X (FLDMDBX, FLDMIAX) -- AArch32" type="instruction">
<docvars>
<docvar key="fpdatasize" value="doubleprec" />
<docvar key="instr-class" value="fpsimd" />
</docvars>
<heading>FLDM*X (FLDMDBX, FLDMIAX)</heading>
<desc>
<brief>
<para>FLDM*X</para>
</brief>
<authored>
<para>FLDMDBX is the Decrement Before variant of this instruction, and FLDMIAX is the Increment After variant. FLDM*X loads multiple SIMD&amp;FP registers from consecutive locations in the Advanced SIMD and floating-point register file using an address from a general-purpose register.</para>
<para>Arm deprecates use of FLDMDBX and FLDMIAX, except for disassembly purposes, and reassembly of disassembled code.</para>
<para>Depending on settings in the <xref linkend="AArch32.cpacr">CPACR</xref>, <xref linkend="AArch32.nsacr">NSACR</xref>, and <xref linkend="AArch32.hcptr">HCPTR</xref> registers, and the Security state and PE mode in which the instruction is executed, an attempt to execute the instruction might be <arm-defined-word>undefined</arm-defined-word>, or trapped to Hyp mode. For more information, see <xref linkend="CIHIDDFF">Enabling Advanced SIMD and floating-point support</xref>.</para>
</authored>
<encodingnotes>
<para>For more information about the <arm-defined-word>constrained unpredictable</arm-defined-word> behavior of this instruction, see <xref linkend="CJAEGDJC">Architectural Constraints on UNPREDICTABLE behaviors</xref>.</para>
<para>Related encodings: See <xref linkend="T32.encoding_index.simdfp_mov64">Advanced SIMD and floating-point 64-bit move</xref> for the T32 instruction set, or <xref linkend="A32.encoding_index.movsimdfpgp64">Advanced SIMD and floating-point 64-bit move</xref> for the A32 instruction set.</para>
</encodingnotes>
</desc>
<operationalnotes>
<para>If CPSR.DIT is 1, the timing of this instruction is insensitive to the value of the data being loaded or stored.</para>
</operationalnotes>
<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="2" isa="A32">
<docvars>
<docvar key="armarmheading" value="A1" />
<docvar key="fpdatasize" value="doubleprec" />
<docvar key="instr-class" value="fpsimd" />
<docvar key="isa" value="A32" />
</docvars>
<iclassintro count="2"></iclassintro>
<regdiagram form="32" psname="aarch32/instrs/VLDM/T1A1_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="3" settings="3">
<c>1</c>
<c>1</c>
<c>0</c>
</box>
<box hibit="24" name="P" usename="1">
<c></c>
</box>
<box hibit="23" name="U" usename="1">
<c></c>
</box>
<box hibit="22" name="D" usename="1">
<c></c>
</box>
<box hibit="21" name="W" usename="1">
<c></c>
</box>
<box hibit="20" name="L" settings="1">
<c>1</c>
</box>
<box hibit="19" width="4" name="Rn" usename="1">
<c colspan="4"></c>
</box>
<box hibit="15" width="4" name="Vd" usename="1">
<c colspan="4"></c>
</box>
<box hibit="11" width="2" settings="2">
<c>1</c>
<c>0</c>
</box>
<box hibit="9" width="2" name="size" settings="2">
<c>1</c>
<c>1</c>
</box>
<box hibit="7" width="7" name="imm8&lt;7:1&gt;" usename="1">
<c colspan="7"></c>
</box>
<box hibit="0" name="imm8&lt;0&gt;" usename="1" settings="1">
<c>1</c>
</box>
</regdiagram>
<encoding name="FLDMDBX_A1" oneofinclass="2" oneof="4" label="Decrement Before" bitdiffs="P == 1 &amp;&amp; U == 0 &amp;&amp; W == 1">
<docvars>
<docvar key="armarmheading" value="A1" />
<docvar key="fpdatasize" value="doubleprec" />
<docvar key="instr-class" value="fpsimd" />
<docvar key="isa" value="A32" />
<docvar key="ldmstm-mode" value="dec-before" />
<docvar key="mnemonic" value="FLDMDBX" />
<docvar key="mnemonic-fpdatasize" value="FLDMDBX-doubleprec" />
</docvars>
<box hibit="24" width="1" name="P">
<c>1</c>
</box>
<box hibit="23" width="1" name="U">
<c>0</c>
</box>
<box hibit="21" width="1" name="W">
<c>1</c>
</box>
<asmtemplate><text>FLDMDBX</text><text>{</text><a link="sa_c" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;c&gt;</a><text>}</text><text>{</text><a link="sa_q" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;q&gt;</a><text>}</text><text> </text><a link="sa_rn" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><text>!, </text><a link="sa_dreglist" hover="List of consecutively numbered 64-bit SIMD&amp;FP registers to be transferred (field &quot;D:Vd&quot;)">&lt;dreglist&gt;</a></asmtemplate>
</encoding>
<encoding name="FLDMIAX_A1" oneofinclass="2" oneof="4" label="Increment After" bitdiffs="P == 0 &amp;&amp; U == 1">
<docvars>
<docvar key="armarmheading" value="A1" />
<docvar key="fpdatasize" value="doubleprec" />
<docvar key="instr-class" value="fpsimd" />
<docvar key="isa" value="A32" />
<docvar key="ldmstm-mode" value="inc-after" />
<docvar key="mnemonic" value="FLDMIAX" />
<docvar key="mnemonic-fpdatasize" value="FLDMIAX-doubleprec" />
</docvars>
<box hibit="24" width="1" name="P">
<c>0</c>
</box>
<box hibit="23" width="1" name="U">
<c>1</c>
</box>
<asmtemplate><text>FLDMIAX</text><text>{</text><a link="sa_c" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;c&gt;</a><text>}</text><text>{</text><a link="sa_q" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;q&gt;</a><text>}</text><text> </text><a link="sa_rn" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><a link="sa_0d33" hover="Specifies base register writeback (field &quot;W&quot;)">{!}</a><text>, </text><a link="sa_dreglist" hover="List of consecutively numbered 64-bit SIMD&amp;FP registers to be transferred (field &quot;D:Vd&quot;)">&lt;dreglist&gt;</a></asmtemplate>
</encoding>
<ps_section howmany="1">
<ps name="aarch32/instrs/VLDM/T1A1_A.txt" mylink="aarch32.instrs.VLDM.T1A1_A.txt" enclabels="" sections="1" secttype="noheading">
<pstext mayhavelinks="1" section="Decode" rep_section="decode">if P == '0' &amp;&amp; U == '0' &amp;&amp; W == '0' then SEE "Related encodings";
if P == '1' &amp;&amp; W == '0' then SEE "VLDR";
if P == U &amp;&amp; W == '1' then UNDEFINED;
// Remaining combinations are PUW = 010 (IA without !), 011 (IA with !), 101 (DB with !)
single_regs = FALSE; add = (U == '1'); wback = (W == '1');
d = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(D:Vd); n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rn); imm32 = <a link="impl-shared.ZeroExtend.2" file="shared_pseudocode.xml" hover="function: bits(N) ZeroExtend(bits(M) x, integer N)">ZeroExtend</a>(imm8:'00', 32);
regs = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(imm8) DIV 2; // If UInt(imm8) is odd, see "FLDM*X".
if n == 15 &amp;&amp; (wback || <a link="impl-shared.CurrentInstrSet.0" file="shared_pseudocode.xml" hover="function: InstrSet CurrentInstrSet()">CurrentInstrSet</a>() != <a link="InstrSet_A32" file="shared_pseudocode.xml" hover="enumeration InstrSet {InstrSet_A64, InstrSet_A32, InstrSet_T32}">InstrSet_A32</a>) then UNPREDICTABLE;
if regs == 0 || regs &gt; 16 || (d+regs) &gt; 32 then UNPREDICTABLE;
if imm8&lt;0&gt; == '1' &amp;&amp; (d+regs) &gt; 16 then UNPREDICTABLE;</pstext>
</ps>
</ps_section>
<constrained_unpredictables encoding="A1" ps_block="Decode">
<cu_case>
<cu_cause>
<pstext mayhavelinks="1">regs == 0</pstext>
</cu_cause>
<cu_type constraint="Constraint_UNDEF" />
<cu_type constraint="Constraint_NOP" />
<cu_type>
<cu_type_text>The instruction operates as a <instruction>VLDM</instruction> with the same addressing mode but loads no registers.</cu_type_text>
</cu_type>
</cu_case>
<cu_case>
<cu_cause>
<pstext mayhavelinks="1">regs &gt; 16 || (d+regs) &gt; 16</pstext>
</cu_cause>
<cu_type constraint="Constraint_UNDEF" />
<cu_type constraint="Constraint_NOP" />
<cu_type>
<cu_type_text>One or more of the SIMD and floating-point registers are <arm-defined-word>unknown</arm-defined-word>. If the instruction specifies writeback, the base register becomes <arm-defined-word>unknown</arm-defined-word>. This behavior does not affect any general-purpose registers.</cu_type_text>
</cu_type>
</cu_case>
</constrained_unpredictables>
</iclass>
<iclass name="T1" oneof="2" id="iclass_t1" no_encodings="2" isa="T32">
<docvars>
<docvar key="armarmheading" value="T1" />
<docvar key="fpdatasize" value="doubleprec" />
<docvar key="instr-class" value="fpsimd" />
<docvar key="isa" value="T32" />
</docvars>
<iclassintro count="2"></iclassintro>
<regdiagram form="16x2" psname="aarch32/instrs/VLDM/T1A1_A.txt" tworows="1">
<box hibit="31" width="7" settings="7">
<c>1</c>
<c>1</c>
<c>1</c>
<c>0</c>
<c>1</c>
<c>1</c>
<c>0</c>
</box>
<box hibit="24" name="P" usename="1">
<c></c>
</box>
<box hibit="23" name="U" usename="1">
<c></c>
</box>
<box hibit="22" name="D" usename="1">
<c></c>
</box>
<box hibit="21" name="W" usename="1">
<c></c>
</box>
<box hibit="20" name="L" settings="1">
<c>1</c>
</box>
<box hibit="19" width="4" name="Rn" usename="1">
<c colspan="4"></c>
</box>
<box hibit="15" width="4" name="Vd" usename="1">
<c colspan="4"></c>
</box>
<box hibit="11" width="2" settings="2">
<c>1</c>
<c>0</c>
</box>
<box hibit="9" width="2" name="size" settings="2">
<c>1</c>
<c>1</c>
</box>
<box hibit="7" width="7" name="imm8&lt;7:1&gt;" usename="1">
<c colspan="7"></c>
</box>
<box hibit="0" name="imm8&lt;0&gt;" usename="1" settings="1">
<c>1</c>
</box>
</regdiagram>
<encoding name="FLDMDBX_T1" oneofinclass="2" oneof="4" label="Decrement Before" bitdiffs="P == 1 &amp;&amp; U == 0 &amp;&amp; W == 1">
<docvars>
<docvar key="armarmheading" value="T1" />
<docvar key="fpdatasize" value="doubleprec" />
<docvar key="instr-class" value="fpsimd" />
<docvar key="isa" value="T32" />
<docvar key="ldmstm-mode" value="dec-before" />
<docvar key="mnemonic" value="FLDMDBX" />
<docvar key="mnemonic-fpdatasize" value="FLDMDBX-doubleprec" />
</docvars>
<box hibit="24" width="1" name="P">
<c>1</c>
</box>
<box hibit="23" width="1" name="U">
<c>0</c>
</box>
<box hibit="21" width="1" name="W">
<c>1</c>
</box>
<asmtemplate><text>FLDMDBX</text><text>{</text><a link="sa_c" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;c&gt;</a><text>}</text><text>{</text><a link="sa_q" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;q&gt;</a><text>}</text><text> </text><a link="sa_rn" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><text>!, </text><a link="sa_dreglist" hover="List of consecutively numbered 64-bit SIMD&amp;FP registers to be transferred (field &quot;D:Vd&quot;)">&lt;dreglist&gt;</a></asmtemplate>
</encoding>
<encoding name="FLDMIAX_T1" oneofinclass="2" oneof="4" label="Increment After" bitdiffs="P == 0 &amp;&amp; U == 1">
<docvars>
<docvar key="armarmheading" value="T1" />
<docvar key="fpdatasize" value="doubleprec" />
<docvar key="instr-class" value="fpsimd" />
<docvar key="isa" value="T32" />
<docvar key="ldmstm-mode" value="inc-after" />
<docvar key="mnemonic" value="FLDMIAX" />
<docvar key="mnemonic-fpdatasize" value="FLDMIAX-doubleprec" />
</docvars>
<box hibit="24" width="1" name="P">
<c>0</c>
</box>
<box hibit="23" width="1" name="U">
<c>1</c>
</box>
<asmtemplate><text>FLDMIAX</text><text>{</text><a link="sa_c" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;c&gt;</a><text>}</text><text>{</text><a link="sa_q" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;q&gt;</a><text>}</text><text> </text><a link="sa_rn" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><a link="sa_0d33" hover="Specifies base register writeback (field &quot;W&quot;)">{!}</a><text>, </text><a link="sa_dreglist" hover="List of consecutively numbered 64-bit SIMD&amp;FP registers to be transferred (field &quot;D:Vd&quot;)">&lt;dreglist&gt;</a></asmtemplate>
</encoding>
<ps_section howmany="1">
<ps name="aarch32/instrs/VLDM/T1A1_A.txt" mylink="aarch32.instrs.VLDM.T1A1_A.txt" enclabels="" sections="1" secttype="noheading">
<pstext mayhavelinks="1" section="Decode" rep_section="decode">if P == '0' &amp;&amp; U == '0' &amp;&amp; W == '0' then SEE "Related encodings";
if P == '1' &amp;&amp; W == '0' then SEE "VLDR";
if P == U &amp;&amp; W == '1' then UNDEFINED;
// Remaining combinations are PUW = 010 (IA without !), 011 (IA with !), 101 (DB with !)
single_regs = FALSE; add = (U == '1'); wback = (W == '1');
d = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(D:Vd); n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rn); imm32 = <a link="impl-shared.ZeroExtend.2" file="shared_pseudocode.xml" hover="function: bits(N) ZeroExtend(bits(M) x, integer N)">ZeroExtend</a>(imm8:'00', 32);
regs = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(imm8) DIV 2; // If UInt(imm8) is odd, see "FLDM*X".
if n == 15 &amp;&amp; (wback || <a link="impl-shared.CurrentInstrSet.0" file="shared_pseudocode.xml" hover="function: InstrSet CurrentInstrSet()">CurrentInstrSet</a>() != <a link="InstrSet_A32" file="shared_pseudocode.xml" hover="enumeration InstrSet {InstrSet_A64, InstrSet_A32, InstrSet_T32}">InstrSet_A32</a>) then UNPREDICTABLE;
if regs == 0 || regs &gt; 16 || (d+regs) &gt; 32 then UNPREDICTABLE;
if imm8&lt;0&gt; == '1' &amp;&amp; (d+regs) &gt; 16 then UNPREDICTABLE;</pstext>
</ps>
</ps_section>
<constrained_unpredictables encoding="T1" ps_block="Decode">
<cu_case>
<cu_cause>
<pstext mayhavelinks="1">regs == 0</pstext>
</cu_cause>
<cu_type constraint="Constraint_UNDEF" />
<cu_type constraint="Constraint_NOP" />
<cu_type>
<cu_type_text>The instruction operates as a <instruction>VLDM</instruction> with the same addressing mode but loads no registers.</cu_type_text>
</cu_type>
</cu_case>
<cu_case>
<cu_cause>
<pstext mayhavelinks="1">regs &gt; 16 || (d+regs) &gt; 16</pstext>
</cu_cause>
<cu_type constraint="Constraint_UNDEF" />
<cu_type constraint="Constraint_NOP" />
<cu_type>
<cu_type_text>One or more of the SIMD and floating-point registers are <arm-defined-word>unknown</arm-defined-word>. If the instruction specifies writeback, the base register becomes <arm-defined-word>unknown</arm-defined-word>. This behavior does not affect any general-purpose registers.</cu_type_text>
</cu_type>
</cu_case>
</constrained_unpredictables>
</iclass>
</classes>
<explanations scope="all">
<explanation enclist="FLDMIAX_A1, FLDMIAX_T1" symboldefcount="1">
<symbol link="sa_c">&lt;c&gt;</symbol>
<account encodedin="">
<intro>
<para>See <xref linkend="Babbefhf">Standard assembler syntax fields</xref>.</para>
</intro>
</account>
</explanation>
<explanation enclist="FLDMIAX_A1, FLDMIAX_T1" symboldefcount="1">
<symbol link="sa_q">&lt;q&gt;</symbol>
<account encodedin="">
<intro>
<para>See <xref linkend="Babbefhf">Standard assembler syntax fields</xref>.</para>
</intro>
</account>
</explanation>
<explanation enclist="FLDMIAX_A1, FLDMIAX_T1" symboldefcount="1">
<symbol link="sa_rn">&lt;Rn&gt;</symbol>
<account encodedin="Rn">
<intro>
<para>Is the general-purpose base register, encoded in the "Rn" field. If writeback is not specified, the PC can be used.</para>
</intro>
</account>
</explanation>
<explanation enclist="FLDMIAX_A1, FLDMIAX_T1" symboldefcount="1">
<symbol link="sa_0d33">!</symbol>
<account encodedin="W">
<intro>
<para>Specifies base register writeback. Encoded in the "W" field as 1 if present, otherwise 0.</para>
</intro>
</account>
</explanation>
<explanation enclist="FLDMIAX_A1, FLDMIAX_T1" symboldefcount="1">
<symbol link="sa_dreglist">&lt;dreglist&gt;</symbol>
<account encodedin="">
<intro>
<para>Is the list of consecutively numbered 64-bit SIMD&amp;FP registers to be transferred. The first register in the list is encoded in "D:Vd", and "imm8" is set to twice the number of registers in the list plus one. The list must contain at least one register, all registers must be in the range D0-D15, and must not contain more than 16 registers.</para>
</intro>
</account>
</explanation>
</explanations>
<ps_section howmany="1">
<ps name="aarch32/instrs/VLDM/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-aarch32.CheckVFPEnabled.1" file="shared_pseudocode.xml" hover="function: CheckVFPEnabled(boolean include_fpexc_check)">CheckVFPEnabled</a>(TRUE);
address = if add then <a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[n] else <a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[n]-imm32;
for r = 0 to regs-1
if single_regs then
<a link="impl-aarch32.S.write.1" file="shared_pseudocode.xml" hover="accessor: S[integer n] = bits(32) value">S</a>[d+r] = <a link="impl-aarch32.MemA.read.2" file="shared_pseudocode.xml" hover="accessor: bits(8*size) MemA[bits(32) address, integer size]">MemA</a>[address,4];
address = address+4;
else
word1 = <a link="impl-aarch32.MemA.read.2" file="shared_pseudocode.xml" hover="accessor: bits(8*size) MemA[bits(32) address, integer size]">MemA</a>[address,4];
word2 = <a link="impl-aarch32.MemA.read.2" file="shared_pseudocode.xml" hover="accessor: bits(8*size) MemA[bits(32) address, integer size]">MemA</a>[address+4,4];
address = address+8;
// Combine the word-aligned words in the correct order for current endianness.
<a link="impl-aarch32.D.write.1" file="shared_pseudocode.xml" hover="accessor: D[integer n] = bits(64) value">D</a>[d+r] = if <a link="impl-shared.BigEndian.1" file="shared_pseudocode.xml" hover="function: boolean BigEndian(AccessType acctype)">BigEndian</a>(<a link="AccessType_ASIMD" file="shared_pseudocode.xml" hover="enumeration AccessType { AccessType_IFETCH, AccessType_GPR, AccessType_ASIMD, AccessType_SVE, AccessType_SME, AccessType_IC, AccessType_DC, AccessType_DCZero, AccessType_AT, AccessType_NV2, AccessType_SPE, AccessType_GCS, AccessType_TRBE, AccessType_GPTW, AccessType_TTW }">AccessType_ASIMD</a>) then word1:word2 else word2:word1;
if wback then <a link="impl-aarch32.R.write.1" file="shared_pseudocode.xml" hover="accessor: R[integer n] = bits(32) value">R</a>[n] = if add then <a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[n]+imm32 else <a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[n]-imm32;</pstext>
</ps>
</ps_section>
</instructionsection>