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<instructionsection id="ld1rob_z_p_br" title="LD1ROB (scalar plus scalar)" type="instruction">
  <docvars>
    <docvar key="instr-class" value="sve" />
    <docvar key="isa" value="A64" />
    <docvar key="mnemonic" value="LD1ROB" />
  </docvars>
  <heading>LD1ROB (scalar plus scalar)</heading>
  <desc>
    <brief>Contiguous load and replicate thirty-two bytes (scalar index)</brief>
    <description>
      <para>Load thirty-two contiguous bytes to elements of a 256-bit (octaword) vector from the memory address generated by a 64-bit scalar base address and scalar index which is added to the base address.</para>
      <para>Inactive elements will not cause a read from Device memory or signal a fault, and are set to zero.</para>
      <para>The resulting 256-bit vector is then replicated to fill the destination vector. The instruction requires that the current vector length is at least 256 bits, and if the current vector length is not an integer multiple of 256 bits then the trailing bits in the destination vector are set to zero.</para>
      <para>Only the first thirty-two predicate elements are used and higher numbered predicate elements are ignored.</para>
      <para>ID_AA64ZFR0_EL1.F64MM indicates whether this instruction is implemented.</para>
      <para>This instruction is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled.</para>
    </description>
    <status>Amber</status>
    <predicated>True</predicated>
    <sm_policy>SM_0_only</sm_policy>
  </desc>
  <alias_list howmany="0"></alias_list>
  <classes>
    <iclass name="SVE" oneof="1" id="iclass_sve" no_encodings="1" isa="A64">
      <docvars>
        <docvar key="instr-class" value="sve" />
        <docvar key="isa" value="A64" />
        <docvar key="mnemonic" value="LD1ROB" />
      </docvars>
      <iclassintro count="1"></iclassintro>
      <arch_variants>
        <arch_variant name="ARMv8.6" feature="FEAT_F64MM" />
      </arch_variants>
      <regdiagram form="32" psname="LD1ROB-Z.P.BR-Contiguous" tworows="1">
        <box hibit="31" width="7" settings="7">
          <c>1</c>
          <c>0</c>
          <c>1</c>
          <c>0</c>
          <c>0</c>
          <c>1</c>
          <c>0</c>
        </box>
        <box hibit="24" name="msz&lt;1&gt;" usename="1" settings="1">
          <c>0</c>
        </box>
        <box hibit="23" name="msz&lt;0&gt;" usename="1" settings="1">
          <c>0</c>
        </box>
        <box hibit="22" width="2" name="ssz" usename="1" settings="2">
          <c>0</c>
          <c>1</c>
        </box>
        <box hibit="20" width="5" name="Rm" usename="1">
          <c colspan="5"></c>
        </box>
        <box hibit="15" width="3" settings="3">
          <c>0</c>
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="12" width="3" name="Pg" usename="1">
          <c colspan="3"></c>
        </box>
        <box hibit="9" width="5" name="Rn" usename="1">
          <c colspan="5"></c>
        </box>
        <box hibit="4" width="5" name="Zt" usename="1">
          <c colspan="5"></c>
        </box>
      </regdiagram>
      <encoding name="ld1rob_z_p_br_contiguous" oneofinclass="1" oneof="1" label="">
        <docvars>
          <docvar key="instr-class" value="sve" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="LD1ROB" />
        </docvars>
        <asmtemplate><text>LD1ROB  </text><text>{</text><text> </text><a link="sa_zt" hover="Scalable vector register to be transferred (field &quot;Zt&quot;)">&lt;Zt&gt;</a><text>.B </text><text>}</text><text>, </text><a link="sa_pg" hover="Governing scalable predicate register P0-P7 (field &quot;Pg&quot;)">&lt;Pg&gt;</a><text>/Z, [</text><a link="sa_xn_sp" hover="64-bit general-purpose base register or SP (field &quot;Rn&quot;)">&lt;Xn|SP&gt;</a><text>, </text><a link="sa_xm" hover="64-bit general-purpose offset register (field &quot;Rm&quot;)">&lt;Xm&gt;</a><text>]</text></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="LD1ROB-Z.P.BR-Contiguous" mylink="LD1ROB-Z.P.BR-Contiguous" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">if !<a link="impl-aarch64.HaveSVE.0" file="shared_pseudocode.xml" hover="function: boolean HaveSVE()">HaveSVE</a>() || !<a link="impl-aarch64.HaveSVEFP64MatMulExt.0" file="shared_pseudocode.xml" hover="function: boolean HaveSVEFP64MatMulExt()">HaveSVEFP64MatMulExt</a>() then UNDEFINED;
if Rm == '11111' then UNDEFINED;
integer t = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zt);
integer n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rn);
integer m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Rm);
integer g = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Pg);
constant integer esize = 8;</pstext>
        </ps>
      </ps_section>
    </iclass>
  </classes>
  <explanations scope="all">
    <explanation enclist="ld1rob_z_p_br_contiguous" symboldefcount="1">
      <symbol link="sa_zt">&lt;Zt&gt;</symbol>
      <account encodedin="Zt">
        <intro>
          <para>Is the name of the scalable vector register to be transferred, encoded in the "Zt" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="ld1rob_z_p_br_contiguous" symboldefcount="1">
      <symbol link="sa_pg">&lt;Pg&gt;</symbol>
      <account encodedin="Pg">
        <intro>
          <para>Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="ld1rob_z_p_br_contiguous" symboldefcount="1">
      <symbol link="sa_xn_sp">&lt;Xn|SP&gt;</symbol>
      <account encodedin="Rn">
        <intro>
          <para>Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="ld1rob_z_p_br_contiguous" symboldefcount="1">
      <symbol link="sa_xm">&lt;Xm&gt;</symbol>
      <account encodedin="Rm">
        <intro>
          <para>Is the 64-bit name of the general-purpose offset register, encoded in the "Rm" field.</para>
        </intro>
      </account>
    </explanation>
  </explanations>
  <ps_section howmany="1">
    <ps name="LD1ROB-Z.P.BR-Contiguous" mylink="execute" enclabels="" sections="1" secttype="Operation">
      <pstext mayhavelinks="1" section="Execute" rep_section="execute"><a link="impl-aarch64.CheckNonStreamingSVEEnabled.0" file="shared_pseudocode.xml" hover="function: CheckNonStreamingSVEEnabled()">CheckNonStreamingSVEEnabled</a>();
constant integer VL = <a link="impl-aarch64.CurrentVL.read.none" file="shared_pseudocode.xml" hover="accessor: integer CurrentVL">CurrentVL</a>;
constant integer PL = VL DIV 8;
if VL &lt; 256 then UNDEFINED;
constant integer elements = 256 DIV esize;
bits(64) base;
bits(PL) mask = <a link="impl-aarch64.P.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) P[integer n, integer width]">P</a>[g, PL]; // low bits only
bits(64) offset;
bits(256) result;
constant integer mbytes = esize DIV 8;
boolean contiguous = TRUE;
boolean nontemporal = FALSE;
boolean tagchecked = TRUE;
<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.CreateAccDescSVE.4" file="shared_pseudocode.xml" hover="function: AccessDescriptor CreateAccDescSVE(MemOp memop, boolean nontemporal, boolean contiguous, boolean tagchecked)">CreateAccDescSVE</a>(<a link="MemOp_LOAD" file="shared_pseudocode.xml" hover="enumeration MemOp {MemOp_LOAD, MemOp_STORE, MemOp_PREFETCH}">MemOp_LOAD</a>, nontemporal, contiguous, tagchecked);

if !<a link="impl-aarch64.AnyActiveElement.2" file="shared_pseudocode.xml" hover="function: boolean AnyActiveElement(bits(N) mask, integer esize)">AnyActiveElement</a>(mask, esize) then
    if n == 31 &amp;&amp; <a link="impl-shared.ConstrainUnpredictableBool.1" file="shared_pseudocode.xml" hover="function: boolean ConstrainUnpredictableBool(Unpredictable which)">ConstrainUnpredictableBool</a>(<a link="Unpredictable_CHECKSPNONEACTIVE" file="shared_pseudocode.xml" hover="enumeration Unpredictable {  Unpredictable_VMSR,  Unpredictable_WBOVERLAPLD,  Unpredictable_WBOVERLAPST,  Unpredictable_LDPOVERLAP,  Unpredictable_BASEOVERLAP,  Unpredictable_DATAOVERLAP,  Unpredictable_DEVPAGE2,  Unpredictable_INSTRDEVICE,  Unpredictable_RESCPACR,  Unpredictable_RESMAIR,  Unpredictable_S1CTAGGED,  Unpredictable_S2RESMEMATTR,  Unpredictable_RESTEXCB,  Unpredictable_RESPRRR,  Unpredictable_RESDACR,  Unpredictable_RESVTCRS,  Unpredictable_RESTnSZ,  Unpredictable_RESTCF,  Unpredictable_DEVICETAGSTORE,  Unpredictable_OORTnSZ,  Unpredictable_LARGEIPA,  Unpredictable_ESRCONDPASS,  Unpredictable_ILZEROIT,  Unpredictable_ILZEROT,  Unpredictable_BPVECTORCATCHPRI,  Unpredictable_VCMATCHHALF,   Unpredictable_VCMATCHDAPA,  Unpredictable_WPMASKANDBAS,  Unpredictable_WPBASCONTIGUOUS,  Unpredictable_RESWPMASK,  Unpredictable_WPMASKEDBITS,  Unpredictable_RESBPWPCTRL,  Unpredictable_BPNOTIMPL,  Unpredictable_RESBPTYPE,  Unpredictable_BPNOTCTXCMP,  Unpredictable_BPMATCHHALF,  Unpredictable_BPMISMATCHHALF,  Unpredictable_RESTARTALIGNPC,  Unpredictable_RESTARTZEROUPPERPC,  Unpredictable_ZEROUPPER,   Unpredictable_ERETZEROUPPERPC,   Unpredictable_A32FORCEALIGNPC,  Unpredictable_SMD,  Unpredictable_NONFAULT,  Unpredictable_SVEZEROUPPER,  Unpredictable_SVELDNFDATA,  Unpredictable_SVELDNFZERO,  Unpredictable_CHECKSPNONEACTIVE,  Unpredictable_SMEZEROUPPER,  Unpredictable_NVNV1,  Unpredictable_Shareability,  Unpredictable_AFUPDATE,  Unpredictable_DBUPDATE,  Unpredictable_IESBinDebug,  Unpredictable_BADPMSFCR,  Unpredictable_ZEROBTYPE,  Unpredictable_EL2TIMESTAMP, Unpredictable_EL1TIMESTAMP,  Unpredictable_RESERVEDNSxB,  Unpredictable_WFxTDEBUG,  Unpredictable_LS64UNSUPPORTED,   Unpredictable_MISALIGNEDATOMIC,  Unpredictable_CLEARERRITEZERO,   Unpredictable_ALUEXCEPTIONRETURN,  Unpredictable_IGNORETRAPINDEBUG,  Unpredictable_DBGxVR_RESS,  Unpredictable_PMUEVENTCOUNTER,  Unpredictable_PMSCR_PCT,   Unpredictable_CounterReservedForEL2,  Unpredictable_BRBFILTRATE,   Unpredictable_MOPSOVERLAP31,  Unpredictable_STOREONLYTAGCHECKEDCAS,  Unpredictable_RESTC }">Unpredictable_CHECKSPNONEACTIVE</a>) then
        <a link="impl-aarch64.CheckSPAlignment.0" file="shared_pseudocode.xml" hover="function: CheckSPAlignment()">CheckSPAlignment</a>();
else
    if n == 31 then <a link="impl-aarch64.CheckSPAlignment.0" file="shared_pseudocode.xml" hover="function: CheckSPAlignment()">CheckSPAlignment</a>();
    base = if n == 31 then <a link="impl-aarch64.SP.read.0" file="shared_pseudocode.xml" hover="accessor: bits(64) SP[]">SP</a>[] else <a link="impl-aarch64.X.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) X[integer n, integer width]">X</a>[n, 64];
    offset = <a link="impl-aarch64.X.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) X[integer n, integer width]">X</a>[m, 64];

for e = 0 to elements-1
    if <a link="impl-aarch64.ActivePredicateElement.3" file="shared_pseudocode.xml" hover="function: boolean ActivePredicateElement(bits(N) pred, integer e, integer esize)">ActivePredicateElement</a>(mask, e, esize) then
        integer eoff = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(offset) + e;
        bits(64) addr = base + eoff * mbytes;
        <a link="impl-shared.Elem.write.3" file="shared_pseudocode.xml" hover="accessor: Elem[bits(N) &amp;vector, integer e, integer size] = bits(size) value">Elem</a>[result, e, esize] = <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>[addr, mbytes, accdesc];
    else
        <a link="impl-shared.Elem.write.3" file="shared_pseudocode.xml" hover="accessor: Elem[bits(N) &amp;vector, integer e, integer size] = bits(size) value">Elem</a>[result, e, esize] = <a link="impl-shared.Zeros.1" file="shared_pseudocode.xml" hover="function: bits(N) Zeros(integer N)">Zeros</a>(esize);

<a link="impl-aarch64.Z.write.2" file="shared_pseudocode.xml" hover="accessor: Z[integer n, integer width] = bits(width) value">Z</a>[t, VL] = <a link="impl-shared.ZeroExtend.2" file="shared_pseudocode.xml" hover="function: bits(N) ZeroExtend(bits(M) x, integer N)">ZeroExtend</a>(<a link="impl-shared.Replicate.2" file="shared_pseudocode.xml" hover="function: bits(M*N) Replicate(bits(M) x, integer N)">Replicate</a>(result, VL DIV 256), VL);</pstext>
    </ps>
  </ps_section>
</instructionsection>
