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<instructionsection id="LDR_lit_gen" title="LDR (literal) -- A64" type="instruction">
  <docvars>
    <docvar key="address-form" value="literal" />
    <docvar key="instr-class" value="general" />
    <docvar key="isa" value="A64" />
    <docvar key="mnemonic" value="LDR" />
    <docvar key="offset-type" value="off19s" />
  </docvars>
  <heading>LDR (literal)</heading>
  <desc>
    <brief>
      <para>Load Register (literal)</para>
    </brief>
    <authored>
      <para>Load Register (literal) calculates an address from the PC value and an immediate offset, loads a word from memory, and writes it to a register. For information about memory accesses, see <xref linkend="CHDIIIBB">Load/Store addressing modes</xref>.</para>
    </authored>
  </desc>
  <operationalnotes>
    <para>If PSTATE.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>
    <iclass name="Literal" oneof="1" id="iclass_literal" no_encodings="2" isa="A64">
      <docvars>
        <docvar key="address-form" value="literal" />
        <docvar key="instr-class" value="general" />
        <docvar key="isa" value="A64" />
        <docvar key="mnemonic" value="LDR" />
        <docvar key="offset-type" value="off19s" />
      </docvars>
      <iclassintro count="2"></iclassintro>
      <regdiagram form="32" psname="aarch64/instrs/memory/literal/general" tworows="1">
        <box hibit="31" width="2" name="opc" usename="1" settings="1" psbits="xx">
          <c>0</c>
          <c>x</c>
        </box>
        <box hibit="29" width="3" settings="3">
          <c>0</c>
          <c>1</c>
          <c>1</c>
        </box>
        <box hibit="26" name="V" settings="1">
          <c>0</c>
        </box>
        <box hibit="25" width="2" settings="2">
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="23" width="19" name="imm19" usename="1">
          <c colspan="19"></c>
        </box>
        <box hibit="4" width="5" name="Rt" usename="1">
          <c colspan="5"></c>
        </box>
      </regdiagram>
      <encoding name="LDR_32_loadlit" oneofinclass="2" oneof="2" label="32-bit" bitdiffs="opc == 00">
        <docvars>
          <docvar key="address-form" value="literal" />
          <docvar key="address-form-reg-type" value="literal-32-reg" />
          <docvar key="atomic-ops" value="LDR-32-reg" />
          <docvar key="instr-class" value="general" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="LDR" />
          <docvar key="offset-type" value="off19s" />
          <docvar key="reg-type" value="32-reg" />
        </docvars>
        <box hibit="31" width="2" name="opc">
          <c></c>
          <c>0</c>
        </box>
        <asmtemplate><text>LDR  </text><a link="sa_wt" hover="32-bit general-purpose register to be loaded (field &quot;Rt&quot;)">&lt;Wt&gt;</a><text>, </text><a link="sa_label" hover="Label from which the data is to be loaded (field imm19)">&lt;label&gt;</a></asmtemplate>
      </encoding>
      <encoding name="LDR_64_loadlit" oneofinclass="2" oneof="2" label="64-bit" bitdiffs="opc == 01">
        <docvars>
          <docvar key="address-form" value="literal" />
          <docvar key="address-form-reg-type" value="literal-64-reg" />
          <docvar key="atomic-ops" value="LDR-64-reg" />
          <docvar key="instr-class" value="general" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="LDR" />
          <docvar key="offset-type" value="off19s" />
          <docvar key="reg-type" value="64-reg" />
        </docvars>
        <box hibit="31" width="2" name="opc">
          <c></c>
          <c>1</c>
        </box>
        <asmtemplate><text>LDR  </text><a link="sa_xt" hover="64-bit general-purpose register to be loaded (field &quot;Rt&quot;)">&lt;Xt&gt;</a><text>, </text><a link="sa_label" hover="Label from which the data is to be loaded (field imm19)">&lt;label&gt;</a></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="aarch64/instrs/memory/literal/general" mylink="aarch64.instrs.memory.literal.general" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">integer t = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rt);
<a link="MemOp" file="shared_pseudocode.xml" hover="enumeration MemOp {MemOp_LOAD, MemOp_STORE, MemOp_PREFETCH}">MemOp</a> memop = <a link="MemOp_LOAD" file="shared_pseudocode.xml" hover="enumeration MemOp {MemOp_LOAD, MemOp_STORE, MemOp_PREFETCH}">MemOp_LOAD</a>;
boolean signed = FALSE;
boolean nontemporal = FALSE;
integer size;
bits(64) offset;

case opc of
    when '00'
        size = 4;
    when '01'
        size = 8;
    when '10'
        size = 4;
        signed = TRUE;
    when '11'
        memop = <a link="MemOp_PREFETCH" file="shared_pseudocode.xml" hover="enumeration MemOp {MemOp_LOAD, MemOp_STORE, MemOp_PREFETCH}">MemOp_PREFETCH</a>;

offset = <a link="impl-shared.SignExtend.2" file="shared_pseudocode.xml" hover="function: bits(N) SignExtend(bits(M) x, integer N)">SignExtend</a>(imm19:'00', 64);
boolean tagchecked = FALSE;</pstext>
        </ps>
      </ps_section>
    </iclass>
  </classes>
  <explanations scope="all">
    <explanation enclist="LDR_32_loadlit" symboldefcount="1">
      <symbol link="sa_wt">&lt;Wt&gt;</symbol>
      <account encodedin="Rt">
        <intro>
          <para>Is the 32-bit name of the general-purpose register to be loaded, encoded in the "Rt" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_64_loadlit" symboldefcount="1">
      <symbol link="sa_xt">&lt;Xt&gt;</symbol>
      <account encodedin="Rt">
        <intro>
          <para>Is the 64-bit name of the general-purpose register to be loaded, encoded in the "Rt" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="LDR_32_loadlit, LDR_64_loadlit" symboldefcount="1">
      <symbol link="sa_label">&lt;label&gt;</symbol>
      <account encodedin="imm19">
        <intro>
          <para>Is the program label from which the data is to be loaded. Its offset from the address of this instruction, in the range +/-1MB, is encoded as "imm19" times 4.</para>
        </intro>
      </account>
    </explanation>
  </explanations>
  <ps_section howmany="1">
    <ps name="aarch64/instrs/memory/literal/general" mylink="execute" enclabels="" sections="1" secttype="Operation">
      <pstext mayhavelinks="1" section="Execute" rep_section="execute">bits(64) address = <a link="impl-aarch64.PC.read.0" file="shared_pseudocode.xml" hover="accessor: bits(64) PC[]">PC</a>[] + offset;
bits(size*8) data;
boolean privileged = PSTATE.EL != <a link="EL0" file="shared_pseudocode.xml" hover="constant bits(2) EL0 = '00'">EL0</a>;

<a link="AccessDescriptor" file="shared_pseudocode.xml" hover="type AccessDescriptor is ( AccessType acctype, bits(2) el, SecurityState ss, boolean acqsc, boolean acqpc, boolean relsc, boolean limitedordered, boolean exclusive, boolean atomicop, MemAtomicOp modop, boolean nontemporal, boolean read, boolean write, CacheOp cacheop, CacheOpScope opscope, CacheType cachetype, boolean pan, boolean transactional, boolean nonfault, boolean firstfault, boolean first, boolean contiguous, boolean streamingsve, boolean ls64, boolean mops, boolean rcw, boolean rcws, boolean toplevel, VARange varange, boolean a32lsmd, boolean tagchecked, boolean tagaccess, MPAMinfo mpam )">AccessDescriptor</a> accdesc = <a link="impl-shared.CreateAccDescGPR.4" file="shared_pseudocode.xml" hover="function: AccessDescriptor CreateAccDescGPR(MemOp memop, boolean nontemporal, boolean privileged, boolean tagchecked)">CreateAccDescGPR</a>(memop, nontemporal, privileged, tagchecked);
case memop of
    when <a link="MemOp_LOAD" file="shared_pseudocode.xml" hover="enumeration MemOp {MemOp_LOAD, MemOp_STORE, MemOp_PREFETCH}">MemOp_LOAD</a>
        data = <a link="impl-aarch64.Mem.read.3" file="shared_pseudocode.xml" hover="accessor: bits(size*8) Mem[bits(64) address, integer size, AccessDescriptor accdesc]">Mem</a>[address, size, accdesc];
        if signed then
            <a link="impl-aarch64.X.write.2" file="shared_pseudocode.xml" hover="accessor: X[integer n, integer width] = bits(width) value">X</a>[t, 64] = <a link="impl-shared.SignExtend.2" file="shared_pseudocode.xml" hover="function: bits(N) SignExtend(bits(M) x, integer N)">SignExtend</a>(data, 64);
        else
            <a link="impl-aarch64.X.write.2" file="shared_pseudocode.xml" hover="accessor: X[integer n, integer width] = bits(width) value">X</a>[t, size*8] = data;

    when <a link="MemOp_PREFETCH" file="shared_pseudocode.xml" hover="enumeration MemOp {MemOp_LOAD, MemOp_STORE, MemOp_PREFETCH}">MemOp_PREFETCH</a>
        <a link="impl-aarch64.Prefetch.2" file="shared_pseudocode.xml" hover="function: Prefetch(bits(64) address, bits(5) prfop)">Prefetch</a>(address, t&lt;4:0&gt;);</pstext>
    </ps>
  </ps_section>
</instructionsection>
