slonik/specs/ldr_r.xml

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<instructionsection id="LDR_r" title="LDR (register) -- AArch32" type="instruction">
  <docvars>
    <docvar key="instr-class" value="general" />
    <docvar key="mnemonic" value="LDR" />
  </docvars>
  <heading>LDR (register)</heading>
  <desc>
    <brief>
      <para>Load Register (register)</para>
    </brief>
    <authored>
      <para>Load Register (register) calculates an address from a base register value and an offset register value, loads a word from memory, and writes it to a register. The offset register value can optionally be shifted. For information about memory accesses, see <xref linkend="Chddjfjf">Memory accesses</xref>.</para>
      <para>The T32 form of <instruction>LDR</instruction> (register) does not support register writeback.</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>
    </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="3">
      <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> and </txt>
      <a href="#iclass_t2">T2</a>
      <txt>)</txt>
      <txt>.</txt>
    </classesintro>
    <iclass name="A1" oneof="3" id="iclass_a1" no_encodings="3" isa="A32">
      <docvars>
        <docvar key="armarmheading" value="A1" />
        <docvar key="instr-class" value="general" />
        <docvar key="isa" value="A32" />
        <docvar key="mnemonic" value="LDR" />
      </docvars>
      <iclassintro count="3"></iclassintro>
      <regdiagram form="32" psname="aarch32/instrs/LDR_r/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="3" settings="3">
          <c>0</c>
          <c>1</c>
          <c>1</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="o2" settings="1">
          <c>0</c>
        </box>
        <box hibit="21" name="W" usename="1">
          <c></c>
        </box>
        <box hibit="20" name="o1" 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="Rt" usename="1">
          <c colspan="4"></c>
        </box>
        <box hibit="11" width="5" name="imm5" usename="1">
          <c colspan="5"></c>
        </box>
        <box hibit="6" width="2" name="stype" usename="1">
          <c colspan="2"></c>
        </box>
        <box hibit="4" settings="1">
          <c>0</c>
        </box>
        <box hibit="3" width="4" name="Rm" usename="1">
          <c colspan="4"></c>
        </box>
      </regdiagram>
      <encoding name="LDR_r_A1_off" oneofinclass="3" oneof="5" label="Offset" bitdiffs="P == 1 &amp;&amp; W == 0">
        <docvars>
          <docvar key="address-form" value="base-plus-offset" />
          <docvar key="address-offset" value="signed-offset" />
          <docvar key="armarmheading" value="A1" />
          <docvar key="instr-class" value="general" />
          <docvar key="isa" value="A32" />
          <docvar key="mnemonic" value="LDR" />
        </docvars>
        <box hibit="24" width="1" name="P">
          <c>1</c>
        </box>
        <box hibit="21" width="1" name="W">
          <c>0</c>
        </box>
        <asmtemplate><text>LDR</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_rt_2" hover="General-purpose register to be transferred (field &quot;Rt&quot;)">&lt;Rt&gt;</a><text>, [</text><a link="sa_rn_1" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><text>, </text><a link="sa__plusminus_" hover="Specifies the index register is added to or subtracted from the base register (field &quot;U&quot;) [+,-]">{+/-}</a><a link="sa_rm" hover="General-purpose index register (field &quot;Rm&quot;)">&lt;Rm&gt;</a><text>{</text><text>, </text><a link="sa_shift" hover="The shift to apply to the value read from {syntax{&lt;Rm&gt;}}">&lt;shift&gt;</a><text>}</text><text>]</text></asmtemplate>
      </encoding>
      <encoding name="LDR_r_A1_post" oneofinclass="3" oneof="5" label="Post-indexed" bitdiffs="P == 0 &amp;&amp; W == 0">
        <docvars>
          <docvar key="address-form" value="post-indexed" />
          <docvar key="armarmheading" value="A1" />
          <docvar key="instr-class" value="general" />
          <docvar key="isa" value="A32" />
          <docvar key="mnemonic" value="LDR" />
        </docvars>
        <box hibit="24" width="1" name="P">
          <c>0</c>
        </box>
        <box hibit="21" width="1" name="W">
          <c>0</c>
        </box>
        <asmtemplate><text>LDR</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_rt_2" hover="General-purpose register to be transferred (field &quot;Rt&quot;)">&lt;Rt&gt;</a><text>, [</text><a link="sa_rn_1" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><text>], </text><a link="sa__plusminus_" hover="Specifies the index register is added to or subtracted from the base register (field &quot;U&quot;) [+,-]">{+/-}</a><a link="sa_rm" hover="General-purpose index register (field &quot;Rm&quot;)">&lt;Rm&gt;</a><text>{</text><text>, </text><a link="sa_shift" hover="The shift to apply to the value read from {syntax{&lt;Rm&gt;}}">&lt;shift&gt;</a><text>}</text></asmtemplate>
      </encoding>
      <encoding name="LDR_r_A1_pre" oneofinclass="3" oneof="5" label="Pre-indexed" bitdiffs="P == 1 &amp;&amp; W == 1">
        <docvars>
          <docvar key="address-form" value="pre-indexed" />
          <docvar key="armarmheading" value="A1" />
          <docvar key="instr-class" value="general" />
          <docvar key="isa" value="A32" />
          <docvar key="mnemonic" value="LDR" />
        </docvars>
        <box hibit="24" width="1" name="P">
          <c>1</c>
        </box>
        <box hibit="21" width="1" name="W">
          <c>1</c>
        </box>
        <asmtemplate><text>LDR</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_rt_2" hover="General-purpose register to be transferred (field &quot;Rt&quot;)">&lt;Rt&gt;</a><text>, [</text><a link="sa_rn_1" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><text>, </text><a link="sa__plusminus_" hover="Specifies the index register is added to or subtracted from the base register (field &quot;U&quot;) [+,-]">{+/-}</a><a link="sa_rm" hover="General-purpose index register (field &quot;Rm&quot;)">&lt;Rm&gt;</a><text>{</text><text>, </text><a link="sa_shift" hover="The shift to apply to the value read from {syntax{&lt;Rm&gt;}}">&lt;shift&gt;</a><text>}</text><text>]!</text></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="aarch32/instrs/LDR_r/A1_A.txt" mylink="aarch32.instrs.LDR_r.A1_A.txt" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">if P == '0' &amp;&amp; W == '1' then SEE "LDRT";
t = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rt);  n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rn);  m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rm);
index = (P == '1');  add = (U == '1');  wback = (P == '0') || (W == '1');
(shift_t, shift_n) = <a link="impl-aarch32.DecodeImmShift.2" file="shared_pseudocode.xml" hover="function: (SRType, integer) DecodeImmShift(bits(2) srtype, bits(5) imm5)">DecodeImmShift</a>(stype, imm5);
if m == 15 then UNPREDICTABLE;
if wback &amp;&amp; (n == 15 || n == t) then UNPREDICTABLE;</pstext>
        </ps>
      </ps_section>
      <constrained_unpredictables encoding="A1" ps_block="Decode">
        <cu_case>
          <cu_cause>
            <pstext mayhavelinks="1">wback &amp;&amp; n == t</pstext>
          </cu_cause>
          <cu_type constraint="Constraint_UNDEF" />
          <cu_type constraint="Constraint_NOP" />
          <cu_type>
            <cu_type_text>The instruction performs all of the loads using the specified addressing mode and the content of the register that is written back is <arm-defined-word>unknown</arm-defined-word>. In addition, if an exception occurs during such as instruction, the base address might be corrupted so that the instruction cannot be repeated.</cu_type_text>
          </cu_type>
        </cu_case>
      </constrained_unpredictables>
    </iclass>
    <iclass name="T1" oneof="3" id="iclass_t1" no_encodings="1" isa="T32">
      <docvars>
        <docvar key="address-form" value="base-plus-offset" />
        <docvar key="armarmheading" value="T1" />
        <docvar key="instr-class" value="general" />
        <docvar key="isa" value="T32" />
        <docvar key="mnemonic" value="LDR" />
      </docvars>
      <iclassintro count="1"></iclassintro>
      <regdiagram form="16" psname="aarch32/instrs/LDR_r/T1_A.txt">
        <box hibit="31" width="4" settings="4">
          <c>0</c>
          <c>1</c>
          <c>0</c>
          <c>1</c>
        </box>
        <box hibit="27" name="L" settings="1">
          <c>1</c>
        </box>
        <box hibit="26" name="B" settings="1">
          <c>0</c>
        </box>
        <box hibit="25" name="H" settings="1">
          <c>0</c>
        </box>
        <box hibit="24" width="3" name="Rm" usename="1">
          <c colspan="3"></c>
        </box>
        <box hibit="21" width="3" name="Rn" usename="1">
          <c colspan="3"></c>
        </box>
        <box hibit="18" width="3" name="Rt" usename="1">
          <c colspan="3"></c>
        </box>
      </regdiagram>
      <encoding name="LDR_r_T1" oneofinclass="1" oneof="5" label="T1">
        <docvars>
          <docvar key="address-form" value="base-plus-offset" />
          <docvar key="armarmheading" value="T1" />
          <docvar key="instr-class" value="general" />
          <docvar key="isa" value="T32" />
          <docvar key="mnemonic" value="LDR" />
        </docvars>
        <asmtemplate><text>LDR</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_rt" hover="General-purpose register to be transferred (field &quot;Rt&quot;)">&lt;Rt&gt;</a><text>, [</text><a link="sa_rn" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><text>, </text><a link="sa__plus_" hover="Specifies the index register is added to the base register">{+}</a><a link="sa_rm" hover="General-purpose index register (field &quot;Rm&quot;)">&lt;Rm&gt;</a><text>]</text></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="aarch32/instrs/LDR_r/T1_A.txt" mylink="aarch32.instrs.LDR_r.T1_A.txt" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">t = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rt);  n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rn);  m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rm);
(shift_t, shift_n) = (<a link="SRType_LSL" file="shared_pseudocode.xml" hover="enumeration SRType {SRType_LSL, SRType_LSR, SRType_ASR, SRType_ROR, SRType_RRX}">SRType_LSL</a>, 0);</pstext>
        </ps>
      </ps_section>
    </iclass>
    <iclass name="T2" oneof="3" id="iclass_t2" no_encodings="1" isa="T32">
      <docvars>
        <docvar key="address-form" value="register-offset" />
        <docvar key="armarmheading" value="T2" />
        <docvar key="instr-class" value="general" />
        <docvar key="isa" value="T32" />
        <docvar key="mnemonic" value="LDR" />
      </docvars>
      <iclassintro count="1"></iclassintro>
      <regdiagram form="16x2" psname="aarch32/instrs/LDR_r/T2_A.txt" tworows="1">
        <box hibit="31" width="9" settings="9">
          <c>1</c>
          <c>1</c>
          <c>1</c>
          <c>1</c>
          <c>1</c>
          <c>0</c>
          <c>0</c>
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="22" width="2" name="size" settings="2">
          <c>1</c>
          <c>0</c>
        </box>
        <box hibit="20" name="L" settings="1">
          <c>1</c>
        </box>
        <box hibit="19" width="4" name="Rn" usename="1" settings="4" constraint="!= 1111">
          <c colspan="4">!= 1111</c>
        </box>
        <box hibit="15" width="4" name="Rt" usename="1">
          <c colspan="4"></c>
        </box>
        <box hibit="11" width="6" settings="6">
          <c>0</c>
          <c>0</c>
          <c>0</c>
          <c>0</c>
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="5" width="2" name="imm2" usename="1">
          <c colspan="2"></c>
        </box>
        <box hibit="3" width="4" name="Rm" usename="1">
          <c colspan="4"></c>
        </box>
      </regdiagram>
      <encoding name="LDR_r_T2" oneofinclass="1" oneof="5" label="T2">
        <docvars>
          <docvar key="address-form" value="register-offset" />
          <docvar key="armarmheading" value="T2" />
          <docvar key="instr-class" value="general" />
          <docvar key="isa" value="T32" />
          <docvar key="mnemonic" value="LDR" />
        </docvars>
        <asmtemplate comment="&lt;Rt&gt;, &lt;Rn&gt;, &lt;Rm&gt; can be represented in T1"><text>LDR</text><text>{</text><a link="sa_c" hover="See {xref{ARMARM_Babbefhf}{Standard assembler syntax fields}}">&lt;c&gt;</a><text>}</text><text>.W </text><a link="sa_rt_1" hover="General-purpose register to be transferred (field &quot;Rt&quot;)">&lt;Rt&gt;</a><text>, [</text><a link="sa_rn" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><text>, </text><a link="sa__plus_" hover="Specifies the index register is added to the base register">{+}</a><a link="sa_rm" hover="General-purpose index register (field &quot;Rm&quot;)">&lt;Rm&gt;</a><text>]</text></asmtemplate>
        <asmtemplate><text>LDR</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_rt_1" hover="General-purpose register to be transferred (field &quot;Rt&quot;)">&lt;Rt&gt;</a><text>, [</text><a link="sa_rn" hover="General-purpose base register (field &quot;Rn&quot;)">&lt;Rn&gt;</a><text>, </text><a link="sa__plus_" hover="Specifies the index register is added to the base register">{+}</a><a link="sa_rm" hover="General-purpose index register (field &quot;Rm&quot;)">&lt;Rm&gt;</a><text>{</text><text>, LSL #</text><a link="sa_imm" hover="If present, the size of left shift to apply to the value from {syntax{&lt;Rm&gt;}}, in the range 1-3">&lt;imm&gt;</a><text>}</text><text>]</text></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="aarch32/instrs/LDR_r/T2_A.txt" mylink="aarch32.instrs.LDR_r.T2_A.txt" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">if Rn == '1111' then SEE "LDR (literal)";
t = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rt);  n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rn);  m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rm);
(shift_t, shift_n) = (<a link="SRType_LSL" file="shared_pseudocode.xml" hover="enumeration SRType {SRType_LSL, SRType_LSR, SRType_ASR, SRType_ROR, SRType_RRX}">SRType_LSL</a>, <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(imm2));
if m == 15 then UNPREDICTABLE; // Armv8-A removes UNPREDICTABLE for R13
if t == 15 &amp;&amp; <a link="impl-aarch32.InITBlock.0" file="shared_pseudocode.xml" hover="function: boolean InITBlock()">InITBlock</a>() &amp;&amp; !<a link="impl-aarch32.LastInITBlock.0" file="shared_pseudocode.xml" hover="function: boolean LastInITBlock()">LastInITBlock</a>() then UNPREDICTABLE;</pstext>
        </ps>
      </ps_section>
    </iclass>
  </classes>
  <explanations scope="all">
    <explanation enclist="LDR_r_A1_off, LDR_r_T1, LDR_r_T2" 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="LDR_r_A1_off, LDR_r_T1, LDR_r_T2" 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="LDR_r_A1_off" symboldefcount="1">
      <symbol link="sa_rt_2">&lt;Rt&gt;</symbol>
      <account encodedin="Rt">
        <docvars>
          <docvar key="address-form" value="base-plus-offset" />
          <docvar key="address-offset" value="signed-offset" />
          <docvar key="armarmheading" value="A1" />
          <docvar key="isa" value="A32" />
        </docvars>
        <intro>
          <para>For encoding A1: is the general-purpose register to be transferred, encoded in the "Rt" field. The PC can be used. If the PC is used, the instruction branches to the address (data) loaded to the PC. This branch is an interworking branch, see <xref linkend="BEICJFEH">Pseudocode description of operations on the AArch32 general-purpose registers and the PC</xref>.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_r_T1" symboldefcount="2">
      <symbol link="sa_rt">&lt;Rt&gt;</symbol>
      <account encodedin="Rt">
        <docvars>
          <docvar key="address-form" value="base-plus-offset" />
          <docvar key="armarmheading" value="T1" />
          <docvar key="isa" value="T32" />
        </docvars>
        <intro>
          <para>For encoding T1: is the general-purpose register to be transferred, encoded in the "Rt" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_r_T2" symboldefcount="3">
      <symbol link="sa_rt_1">&lt;Rt&gt;</symbol>
      <account encodedin="Rt">
        <docvars>
          <docvar key="address-form" value="register-offset" />
          <docvar key="armarmheading" value="T2" />
          <docvar key="isa" value="T32" />
        </docvars>
        <intro>
          <para>For encoding T2: is the general-purpose register to be transferred, encoded in the "Rt" field. The PC can be used, provided the instruction is either outside an IT block or the last instruction of an IT block. If the PC is used, the instruction branches to the address (data) loaded to the PC. This is an interworking branch, see <xref linkend="BEICJFEH">Pseudocode description of operations on the AArch32 general-purpose registers and the PC</xref>.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_r_A1_off" symboldefcount="1">
      <symbol link="sa_rn_1">&lt;Rn&gt;</symbol>
      <account encodedin="Rn">
        <docvars>
          <docvar key="address-form" value="base-plus-offset" />
          <docvar key="address-offset" value="signed-offset" />
          <docvar key="armarmheading" value="A1" />
          <docvar key="isa" value="A32" />
        </docvars>
        <intro>
          <para>For encoding A1: is the general-purpose base register, encoded in the "Rn" field. The PC can be used in the offset variant.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_r_T1, LDR_r_T2" symboldefcount="2">
      <symbol link="sa_rn">&lt;Rn&gt;</symbol>
      <account encodedin="Rn">
        <docvars>
          <docvar key="isa" value="T32" />
        </docvars>
        <intro>
          <para>For encoding T1 and T2: is the general-purpose base register, encoded in the "Rn" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_r_A1_off" symboldefcount="1">
      <symbol link="sa__plusminus_">+/-</symbol>
      <definition encodedin="U">
        <intro>Specifies the index register is added to or subtracted from the base register, defaulting to + if omitted and </intro>
        <table class="valuetable">
          <tgroup cols="2">
            <thead>
              <row>
                <entry class="bitfield">U</entry>
                <entry class="symbol">+/-</entry>
              </row>
            </thead>
            <tbody>
              <row>
                <entry class="bitfield">0</entry>
                <entry class="symbol">-</entry>
              </row>
              <row>
                <entry class="bitfield">1</entry>
                <entry class="symbol">+</entry>
              </row>
            </tbody>
          </tgroup>
        </table>
      </definition>
    </explanation>
    <explanation enclist="LDR_r_T1, LDR_r_T2" symboldefcount="1">
      <symbol link="sa__plus_">+</symbol>
      <account encodedin="">
        <intro>
          <para>Specifies the index register is added to the base register.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_r_A1_off, LDR_r_T1, LDR_r_T2" symboldefcount="1">
      <symbol link="sa_rm">&lt;Rm&gt;</symbol>
      <account encodedin="Rm">
        <intro>
          <para>Is the general-purpose index register, encoded in the "Rm" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_r_A1_off" symboldefcount="1">
      <symbol link="sa_shift">&lt;shift&gt;</symbol>
      <account encodedin="">
        <intro>
          <para>The shift to apply to the value read from <syntax>&lt;Rm&gt;</syntax>. If absent, no shift is applied. Otherwise, see <xref linkend="Chdibjii">Shifts applied to a register</xref>.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_r_T2" symboldefcount="1">
      <symbol link="sa_imm">&lt;imm&gt;</symbol>
      <account encodedin="">
        <intro>
          <para>If present, the size of the left shift to apply to the value from <syntax>&lt;Rm&gt;</syntax>, in the range 1-3. <syntax>&lt;imm&gt;</syntax> is encoded in imm2. If absent, no shift is specified and imm2 is encoded as <binarynumber>0b00</binarynumber>.</para>
        </intro>
      </account>
    </explanation>
  </explanations>
  <ps_section howmany="1">
    <ps name="aarch32/instrs/LDR_r/Op_A.txt" mylink="execute" enclabels="" sections="1" secttype="Operation">
      <pstext mayhavelinks="1" section="Execute" rep_section="execute">if <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
    if <a link="impl-aarch32.ConditionPassed.0" file="shared_pseudocode.xml" hover="function: boolean ConditionPassed()">ConditionPassed</a>() then
        EncodingSpecificOperations();
        offset = <a link="impl-aarch32.Shift.4" file="shared_pseudocode.xml" hover="function: bits(N) Shift(bits(N) value, SRType srtype, integer amount, bit carry_in)">Shift</a>(<a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[m], shift_t, shift_n, PSTATE.C);
        offset_addr = if add then (<a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[n] + offset) else (<a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[n] - offset);
        address = if index then offset_addr else <a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[n];
        data = <a link="impl-aarch32.MemU.read.2" file="shared_pseudocode.xml" hover="accessor: bits(8*size) MemU[bits(32) address, integer size]">MemU</a>[address,4];
        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] = offset_addr;
        if t == 15 then
            if address&lt;1:0&gt; == '00' then
                <a link="impl-aarch32.LoadWritePC.1" file="shared_pseudocode.xml" hover="function: LoadWritePC(bits(32) address)">LoadWritePC</a>(data);
            else
                UNPREDICTABLE;
        else
            <a link="impl-aarch32.R.write.1" file="shared_pseudocode.xml" hover="accessor: R[integer n] = bits(32) value">R</a>[t] = data;
else
    if <a link="impl-aarch32.ConditionPassed.0" file="shared_pseudocode.xml" hover="function: boolean ConditionPassed()">ConditionPassed</a>() then
        EncodingSpecificOperations();
        offset = <a link="impl-aarch32.Shift.4" file="shared_pseudocode.xml" hover="function: bits(N) Shift(bits(N) value, SRType srtype, integer amount, bit carry_in)">Shift</a>(<a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[m], shift_t, shift_n, PSTATE.C);
        offset_addr = (<a link="impl-aarch32.R.read.1" file="shared_pseudocode.xml" hover="accessor: bits(32) R[integer n]">R</a>[n] + offset);
        address = offset_addr;
        data = <a link="impl-aarch32.MemU.read.2" file="shared_pseudocode.xml" hover="accessor: bits(8*size) MemU[bits(32) address, integer size]">MemU</a>[address,4];
        if t == 15 then
            if address&lt;1:0&gt; == '00' then
                <a link="impl-aarch32.LoadWritePC.1" file="shared_pseudocode.xml" hover="function: LoadWritePC(bits(32) address)">LoadWritePC</a>(data);
            else
                UNPREDICTABLE;
        else
            <a link="impl-aarch32.R.write.1" file="shared_pseudocode.xml" hover="accessor: R[integer n] = bits(32) value">R</a>[t] = data;</pstext>
    </ps>
  </ps_section>
</instructionsection>