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<instructionsection id="udot_za32_zzi" title="UDOT (2-way, multiple and indexed vector)" type="instruction">
  <docvars>
    <docvar key="instr-class" value="mortlach2" />
    <docvar key="isa" value="A64" />
    <docvar key="mnemonic" value="UDOT" />
  </docvars>
  <heading>UDOT (2-way, multiple and indexed vector)</heading>
  <desc>
    <brief>Multi-vector unsigned integer dot-product by indexed element</brief>
    <description>
      <para>The instruction operates on two or four ZA single-vector groups.</para>
      <para>The unsigned integer dot product instruction computes the dot product of two unsigned 16-bit integer values held in each 32-bit element of the two or four first source vectors and two unsigned 16-bit integer values in the corresponding indexed 32-bit element of the second source vector. The widened dot product result is destructively added to the corresponding 32-bit element of the two or four ZA single-vector groups.</para>
      <para>The groups within the second source vector are specified using an immediate element index which selects the same group position within each 128-bit vector segment. The index range is from 0 to 3, encoded in 2 bits. The vector numbers forming the single-vector group within each half or each quarter of the ZA array are selected by the sum of the vector select register and immediate offset, modulo half or quarter the number of ZA array vectors.</para>
      <para>The <arm-defined-word>vector group</arm-defined-word> symbol, <syntax>VGx2</syntax> or <syntax>VGx4</syntax>, indicates that the ZA operand consists of two or four ZA single-vector groups respectively. The <arm-defined-word>vector group</arm-defined-word> symbol is preferred for disassembly, but optional in assembler source code.</para>
      <para>This instruction is unpredicated.</para>
    </description>
    <status>Green</status>
    <predicated>False</predicated>
    <sm_policy>SM_1_only</sm_policy>
  </desc>
  <alias_list howmany="0"></alias_list>
  <classes>
    <classesintro count="2">
      <txt>It has encodings from 2 classes:</txt>
      <a href="#iclass_sme_vgx2_single">Two ZA single-vectors</a>
      <txt> and </txt>
      <a href="#iclass_sme_vgx4_single">Four ZA single-vectors</a>
    </classesintro>
    <iclass name="Two ZA single-vectors" oneof="2" id="iclass_sme_vgx2_single" no_encodings="1" isa="A64">
      <docvars>
        <docvar key="instr-class" value="mortlach2" />
        <docvar key="isa" value="A64" />
        <docvar key="mnemonic" value="UDOT" />
        <docvar key="sme-multireg" value="sme-vgx2-single" />
      </docvars>
      <iclassintro count="1"></iclassintro>
      <arch_variants>
        <arch_variant name="FEAT_SME2" feature="FEAT_SME2" />
      </arch_variants>
      <regdiagram form="32" psname="UDOT-ZA32.ZZi-2xi" tworows="1">
        <box hibit="31" width="12" settings="12">
          <c>1</c>
          <c>1</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>0</c>
          <c>1</c>
        </box>
        <box hibit="19" width="4" name="Zm" usename="1">
          <c colspan="4"></c>
        </box>
        <box hibit="15" settings="1">
          <c>0</c>
        </box>
        <box hibit="14" width="2" name="Rv" usename="1">
          <c colspan="2"></c>
        </box>
        <box hibit="12" name="op" settings="1">
          <c>1</c>
        </box>
        <box hibit="11" width="2" name="i2" usename="1">
          <c colspan="2"></c>
        </box>
        <box hibit="9" width="4" name="Zn" usename="1">
          <c colspan="4"></c>
        </box>
        <box hibit="5" settings="1">
          <c>0</c>
        </box>
        <box hibit="4" name="U" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="3" settings="1">
          <c>0</c>
        </box>
        <box hibit="2" width="3" name="off3" usename="1">
          <c colspan="3"></c>
        </box>
      </regdiagram>
      <encoding name="udot_za32_zzi_2xi" oneofinclass="1" oneof="2" label="">
        <docvars>
          <docvar key="instr-class" value="mortlach2" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="UDOT" />
          <docvar key="sme-multireg" value="sme-vgx2-single" />
        </docvars>
        <asmtemplate><text>UDOT    ZA.S[</text><a link="sa_wv" hover="32-bit vector select register W8-W11 (field &quot;Rv&quot;)">&lt;Wv&gt;</a><text>, </text><a link="sa_offs" hover="Vector select offset [0-7] (field &quot;off3&quot;)">&lt;offs&gt;</a><a>{, VGx2}</a><text>], </text><text>{</text><text> </text><a link="sa_zn1" hover="First scalable vector register of a multi-vector sequence (field Zn)">&lt;Zn1&gt;</a><text>.H-</text><a link="sa_zn2" hover="Second scalable vector register of a multi-vector sequence (field Zn)">&lt;Zn2&gt;</a><text>.H </text><text>}</text><text>, </text><a link="sa_zm" hover="Second source scalable vector register Z0-Z15 (field &quot;Zm&quot;)">&lt;Zm&gt;</a><text>.H[</text><a link="sa_index" hover="Element index [0-3] (field &quot;i2&quot;)">&lt;index&gt;</a><text>]</text></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="UDOT-ZA32.ZZi-2xi" mylink="UDOT-ZA32.ZZi-2xi" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">if !<a link="impl-aarch64.HaveSME2.0" file="shared_pseudocode.xml" hover="function: boolean HaveSME2()">HaveSME2</a>() then UNDEFINED;
integer v = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>('010':Rv);
constant integer esize = 32;
integer n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zn:'0');
integer m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>('0':Zm);
integer offset = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(off3);
integer index = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(i2);
constant integer nreg = 2;</pstext>
        </ps>
      </ps_section>
    </iclass>
    <iclass name="Four ZA single-vectors" oneof="2" id="iclass_sme_vgx4_single" no_encodings="1" isa="A64">
      <docvars>
        <docvar key="instr-class" value="mortlach2" />
        <docvar key="isa" value="A64" />
        <docvar key="mnemonic" value="UDOT" />
        <docvar key="sme-multireg" value="sme-vgx4-single" />
      </docvars>
      <iclassintro count="1"></iclassintro>
      <arch_variants>
        <arch_variant name="FEAT_SME2" feature="FEAT_SME2" />
      </arch_variants>
      <regdiagram form="32" psname="UDOT-ZA32.ZZi-4xi" tworows="1">
        <box hibit="31" width="12" settings="12">
          <c>1</c>
          <c>1</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>0</c>
          <c>1</c>
        </box>
        <box hibit="19" width="4" name="Zm" usename="1">
          <c colspan="4"></c>
        </box>
        <box hibit="15" settings="1">
          <c>1</c>
        </box>
        <box hibit="14" width="2" name="Rv" usename="1">
          <c colspan="2"></c>
        </box>
        <box hibit="12" name="op" settings="1">
          <c>1</c>
        </box>
        <box hibit="11" width="2" name="i2" usename="1">
          <c colspan="2"></c>
        </box>
        <box hibit="9" width="3" name="Zn" usename="1">
          <c colspan="3"></c>
        </box>
        <box hibit="6" settings="1">
          <c>0</c>
        </box>
        <box hibit="5" settings="1">
          <c>0</c>
        </box>
        <box hibit="4" name="U" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="3" settings="1">
          <c>0</c>
        </box>
        <box hibit="2" width="3" name="off3" usename="1">
          <c colspan="3"></c>
        </box>
      </regdiagram>
      <encoding name="udot_za32_zzi_4xi" oneofinclass="1" oneof="2" label="">
        <docvars>
          <docvar key="instr-class" value="mortlach2" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="UDOT" />
          <docvar key="sme-multireg" value="sme-vgx4-single" />
        </docvars>
        <asmtemplate><text>UDOT    ZA.S[</text><a link="sa_wv" hover="32-bit vector select register W8-W11 (field &quot;Rv&quot;)">&lt;Wv&gt;</a><text>, </text><a link="sa_offs" hover="Vector select offset [0-7] (field &quot;off3&quot;)">&lt;offs&gt;</a><a>{, VGx4}</a><text>], </text><text>{</text><text> </text><a link="sa_zn1_1" hover="First scalable vector register of a multi-vector sequence (field Zn)">&lt;Zn1&gt;</a><text>.H-</text><a link="sa_zn4" hover="Fourth scalable vector register of a multi-vector sequence (field Zn)">&lt;Zn4&gt;</a><text>.H </text><text>}</text><text>, </text><a link="sa_zm" hover="Second source scalable vector register Z0-Z15 (field &quot;Zm&quot;)">&lt;Zm&gt;</a><text>.H[</text><a link="sa_index" hover="Element index [0-3] (field &quot;i2&quot;)">&lt;index&gt;</a><text>]</text></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="UDOT-ZA32.ZZi-4xi" mylink="UDOT-ZA32.ZZi-4xi" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">if !<a link="impl-aarch64.HaveSME2.0" file="shared_pseudocode.xml" hover="function: boolean HaveSME2()">HaveSME2</a>() then UNDEFINED;
integer v = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>('010':Rv);
constant integer esize = 32;
integer n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zn:'00');
integer m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>('0':Zm);
integer offset = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(off3);
integer index = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(i2);
constant integer nreg = 4;</pstext>
        </ps>
      </ps_section>
    </iclass>
  </classes>
  <explanations scope="all">
    <explanation enclist="udot_za32_zzi_2xi, udot_za32_zzi_4xi" symboldefcount="1">
      <symbol link="sa_wv">&lt;Wv&gt;</symbol>
      <account encodedin="Rv">
        <intro>
          <para>Is the 32-bit name of the vector select register W8-W11, encoded in the "Rv" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="udot_za32_zzi_2xi, udot_za32_zzi_4xi" symboldefcount="1">
      <symbol link="sa_offs">&lt;offs&gt;</symbol>
      <account encodedin="off3">
        <intro>
          <para>Is the vector select offset, in the range 0 to 7, encoded in the "off3" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="udot_za32_zzi_2xi" symboldefcount="1">
      <symbol link="sa_zn1">&lt;Zn1&gt;</symbol>
      <account encodedin="Zn">
        <docvars>
          <docvar key="sme-multireg" value="sme-vgx2-single" />
        </docvars>
        <intro>
          <para>For the two ZA single-vectors variant: is the name of the first scalable vector register of a multi-vector sequence, encoded as "Zn" times 2.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="udot_za32_zzi_4xi" symboldefcount="2">
      <symbol link="sa_zn1_1">&lt;Zn1&gt;</symbol>
      <account encodedin="Zn">
        <docvars>
          <docvar key="sme-multireg" value="sme-vgx4-single" />
        </docvars>
        <intro>
          <para>For the four ZA single-vectors variant: is the name of the first scalable vector register of a multi-vector sequence, encoded as "Zn" times 4.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="udot_za32_zzi_4xi" symboldefcount="1">
      <symbol link="sa_zn4">&lt;Zn4&gt;</symbol>
      <account encodedin="Zn">
        <intro>
          <para>Is the name of the fourth scalable vector register of a multi-vector sequence, encoded as "Zn" times 4 plus 3.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="udot_za32_zzi_2xi" symboldefcount="1">
      <symbol link="sa_zn2">&lt;Zn2&gt;</symbol>
      <account encodedin="Zn">
        <intro>
          <para>Is the name of the second scalable vector register of a multi-vector sequence, encoded as "Zn" times 2 plus 1.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="udot_za32_zzi_2xi, udot_za32_zzi_4xi" symboldefcount="1">
      <symbol link="sa_zm">&lt;Zm&gt;</symbol>
      <account encodedin="Zm">
        <intro>
          <para>Is the name of the second source scalable vector register Z0-Z15, encoded in the "Zm" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="udot_za32_zzi_2xi, udot_za32_zzi_4xi" symboldefcount="1">
      <symbol link="sa_index">&lt;index&gt;</symbol>
      <account encodedin="i2">
        <intro>
          <para>Is the element index, in the range 0 to 3, encoded in the "i2" field.</para>
        </intro>
      </account>
    </explanation>
  </explanations>
  <ps_section howmany="1">
    <ps name="UDOT-ZA32.ZZi-2xi" mylink="execute" enclabels="" sections="1" secttype="Operation">
      <pstext mayhavelinks="1" section="Execute" rep_section="execute"><a link="impl-aarch64.CheckStreamingSVEAndZAEnabled.0" file="shared_pseudocode.xml" hover="function: CheckStreamingSVEAndZAEnabled()">CheckStreamingSVEAndZAEnabled</a>();
constant integer VL = <a link="impl-aarch64.CurrentVL.read.none" file="shared_pseudocode.xml" hover="accessor: integer CurrentVL">CurrentVL</a>;
constant integer elements = VL DIV esize;
integer vectors = VL DIV 8;
integer vstride = vectors DIV nreg;
integer eltspersegment = 128 DIV esize;
bits(32) vbase = <a link="impl-aarch64.X.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) X[integer n, integer width]">X</a>[v, 32];
integer vec = (<a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(vbase) + offset) MOD vstride;
bits(VL) result;

for r = 0 to nreg-1
    bits(VL) operand1 = <a link="impl-aarch64.Z.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) Z[integer n, integer width]">Z</a>[n+r, VL];
    bits(VL) operand2 = <a link="impl-aarch64.Z.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) Z[integer n, integer width]">Z</a>[m, VL];
    bits(VL) operand3 = <a link="impl-aarch64.ZAvector.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) ZAvector[integer index, integer width]">ZAvector</a>[vec, VL];
    for e = 0 to elements-1
        bits(esize) sum = <a link="impl-shared.Elem.read.3" file="shared_pseudocode.xml" hover="accessor: bits(size) Elem[bits(N) vector, integer e, integer size]">Elem</a>[operand3, e, esize];
        integer segmentbase = e - (e MOD eltspersegment);
        integer s = segmentbase + index;
        for i = 0 to 1
            integer element1 = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(<a link="impl-shared.Elem.read.3" file="shared_pseudocode.xml" hover="accessor: bits(size) Elem[bits(N) vector, integer e, integer size]">Elem</a>[operand1, 2 * e + i, esize DIV 2]);
            integer element2 = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(<a link="impl-shared.Elem.read.3" file="shared_pseudocode.xml" hover="accessor: bits(size) Elem[bits(N) vector, integer e, integer size]">Elem</a>[operand2, 2 * s + i, esize DIV 2]);
            sum = sum + element1 * element2;
        <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] = sum;
    <a link="impl-aarch64.ZAvector.write.2" file="shared_pseudocode.xml" hover="accessor: ZAvector[integer index, integer width] = bits(width) value">ZAvector</a>[vec, VL] = result;
    vec = vec + vstride;</pstext>
    </ps>
  </ps_section>
</instructionsection>
