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<instructionsection id="smlslt_z_zzzi" title="SMLSLT (indexed)" type="instruction">
  <docvars>
    <docvar key="instr-class" value="sve2" />
    <docvar key="isa" value="A64" />
    <docvar key="mnemonic" value="SMLSLT" />
  </docvars>
  <heading>SMLSLT (indexed)</heading>
  <desc>
    <brief>Signed multiply-subtract long from accumulator (top, indexed)</brief>
    <description>
      <para>Multiply the odd-numbered signed elements within each 128-bit segment of the first source vector by the specified signed element in the corresponding second source vector segment and destructively subtract from the overlapping double-width elements of the addend vector.</para>
      <para>The elements within the second source vector are specified using an immediate index which selects the same element position within each 128-bit vector segment. The index range is from 0 to one less than the number of elements per 128-bit segment, encoded in 2 or 3 bits depending on the size of the element.</para>
    </description>
    <status>Green</status>
    <predicated>False</predicated>
    <uses_dit condition="FEAT_SVE2 is implemented or FEAT_SME is implemented">True</uses_dit>
    <takes_movprfx>True</takes_movprfx>
  </desc>
  <alias_list howmany="0"></alias_list>
  <classes>
    <classesintro count="2">
      <txt>It has encodings from 2 classes:</txt>
      <a href="#iclass_of_words">32-bit</a>
      <txt> and </txt>
      <a href="#iclass_of_doublewords">64-bit</a>
    </classesintro>
    <iclass name="32-bit" oneof="2" id="iclass_of_words" no_encodings="1" isa="A64">
      <docvars>
        <docvar key="as-structure-org" value="of-words" />
        <docvar key="instr-class" value="sve2" />
        <docvar key="isa" value="A64" />
        <docvar key="mnemonic" value="SMLSLT" />
      </docvars>
      <iclassintro count="1"></iclassintro>
      <regdiagram form="32" psname="SMLSLT-Z.ZZZi-S" tworows="1">
        <box hibit="31" width="8" settings="8">
          <c>0</c>
          <c>1</c>
          <c>0</c>
          <c>0</c>
          <c>0</c>
          <c>1</c>
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="23" name="size&lt;1&gt;" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="22" name="size&lt;0&gt;" usename="1" settings="1">
          <c>0</c>
        </box>
        <box hibit="21" settings="1">
          <c>1</c>
        </box>
        <box hibit="20" width="2" name="i3h" usename="1">
          <c colspan="2"></c>
        </box>
        <box hibit="18" width="3" name="Zm" usename="1">
          <c colspan="3"></c>
        </box>
        <box hibit="15" width="2" settings="2">
          <c>1</c>
          <c>0</c>
        </box>
        <box hibit="13" name="S" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="12" name="U" usename="1" settings="1">
          <c>0</c>
        </box>
        <box hibit="11" name="i3l" usename="1">
          <c></c>
        </box>
        <box hibit="10" name="T" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="9" width="5" name="Zn" usename="1">
          <c colspan="5"></c>
        </box>
        <box hibit="4" width="5" name="Zda" usename="1">
          <c colspan="5"></c>
        </box>
      </regdiagram>
      <encoding name="smlslt_z_zzzi_s" oneofinclass="1" oneof="2" label="">
        <docvars>
          <docvar key="as-structure-org" value="of-words" />
          <docvar key="instr-class" value="sve2" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="SMLSLT" />
        </docvars>
        <asmtemplate><text>SMLSLT  </text><a link="sa_zda" hover="Third source and destination scalable vector register (field &quot;Zda&quot;)">&lt;Zda&gt;</a><text>.S, </text><a link="sa_zn" hover="First source scalable vector register (field &quot;Zn&quot;)">&lt;Zn&gt;</a><text>.H, </text><a link="sa_zm_1" hover="Second source scalable vector register Z0-Z7 (field &quot;Zm&quot;)">&lt;Zm&gt;</a><text>.H[</text><a link="sa_imm_1" hover="Element index [0-7] (field &quot;i3h:i3l&quot;)">&lt;imm&gt;</a><text>]</text></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="SMLSLT-Z.ZZZi-S" mylink="SMLSLT-Z.ZZZi-S" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">if !<a link="impl-aarch64.HaveSVE2.0" file="shared_pseudocode.xml" hover="function: boolean HaveSVE2()">HaveSVE2</a>() &amp;&amp; !<a link="impl-aarch64.HaveSME.0" file="shared_pseudocode.xml" hover="function: boolean HaveSME()">HaveSME</a>() then UNDEFINED;
constant integer esize = 16;
integer index = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(i3h:i3l);
integer n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zn);
integer m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zm);
integer da = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zda);
integer sel = 1;</pstext>
        </ps>
      </ps_section>
    </iclass>
    <iclass name="64-bit" oneof="2" id="iclass_of_doublewords" no_encodings="1" isa="A64">
      <docvars>
        <docvar key="as-structure-org" value="of-doublewords" />
        <docvar key="instr-class" value="sve2" />
        <docvar key="isa" value="A64" />
        <docvar key="mnemonic" value="SMLSLT" />
      </docvars>
      <iclassintro count="1"></iclassintro>
      <regdiagram form="32" psname="SMLSLT-Z.ZZZi-D" tworows="1">
        <box hibit="31" width="8" settings="8">
          <c>0</c>
          <c>1</c>
          <c>0</c>
          <c>0</c>
          <c>0</c>
          <c>1</c>
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="23" name="size&lt;1&gt;" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="22" name="size&lt;0&gt;" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="21" settings="1">
          <c>1</c>
        </box>
        <box hibit="20" name="i2h" usename="1">
          <c></c>
        </box>
        <box hibit="19" width="4" name="Zm" usename="1">
          <c colspan="4"></c>
        </box>
        <box hibit="15" width="2" settings="2">
          <c>1</c>
          <c>0</c>
        </box>
        <box hibit="13" name="S" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="12" name="U" usename="1" settings="1">
          <c>0</c>
        </box>
        <box hibit="11" name="i2l" usename="1">
          <c></c>
        </box>
        <box hibit="10" name="T" usename="1" settings="1">
          <c>1</c>
        </box>
        <box hibit="9" width="5" name="Zn" usename="1">
          <c colspan="5"></c>
        </box>
        <box hibit="4" width="5" name="Zda" usename="1">
          <c colspan="5"></c>
        </box>
      </regdiagram>
      <encoding name="smlslt_z_zzzi_d" oneofinclass="1" oneof="2" label="">
        <docvars>
          <docvar key="as-structure-org" value="of-doublewords" />
          <docvar key="instr-class" value="sve2" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="SMLSLT" />
        </docvars>
        <asmtemplate><text>SMLSLT  </text><a link="sa_zda" hover="Third source and destination scalable vector register (field &quot;Zda&quot;)">&lt;Zda&gt;</a><text>.D, </text><a link="sa_zn" hover="First source scalable vector register (field &quot;Zn&quot;)">&lt;Zn&gt;</a><text>.S, </text><a link="sa_zm" hover="Second source scalable vector register Z0-Z15 (field &quot;Zm&quot;)">&lt;Zm&gt;</a><text>.S[</text><a link="sa_imm" hover="Element index [0-3] (field &quot;i2h:i2l&quot;)">&lt;imm&gt;</a><text>]</text></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="SMLSLT-Z.ZZZi-D" mylink="SMLSLT-Z.ZZZi-D" enclabels="" sections="1" secttype="noheading">
          <pstext mayhavelinks="1" section="Decode" rep_section="decode">if !<a link="impl-aarch64.HaveSVE2.0" file="shared_pseudocode.xml" hover="function: boolean HaveSVE2()">HaveSVE2</a>() &amp;&amp; !<a link="impl-aarch64.HaveSME.0" file="shared_pseudocode.xml" hover="function: boolean HaveSME()">HaveSME</a>() then UNDEFINED;
constant integer esize = 32;
integer index = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(i2h:i2l);
integer n = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zn);
integer m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zm);
integer da = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zda);
integer sel = 1;</pstext>
        </ps>
      </ps_section>
    </iclass>
  </classes>
  <explanations scope="all">
    <explanation enclist="smlslt_z_zzzi_d, smlslt_z_zzzi_s" symboldefcount="1">
      <symbol link="sa_zda">&lt;Zda&gt;</symbol>
      <account encodedin="Zda">
        <intro>
          <para>Is the name of the third source and destination scalable vector register, encoded in the "Zda" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="smlslt_z_zzzi_d, smlslt_z_zzzi_s" symboldefcount="1">
      <symbol link="sa_zn">&lt;Zn&gt;</symbol>
      <account encodedin="Zn">
        <intro>
          <para>Is the name of the first source scalable vector register, encoded in the "Zn" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="smlslt_z_zzzi_s" symboldefcount="1">
      <symbol link="sa_zm_1">&lt;Zm&gt;</symbol>
      <account encodedin="Zm">
        <docvars>
          <docvar key="as-structure-org" value="of-words" />
        </docvars>
        <intro>
          <para>For the 32-bit variant: is the name of the second source scalable vector register Z0-Z7, encoded in the "Zm" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="smlslt_z_zzzi_d" symboldefcount="2">
      <symbol link="sa_zm">&lt;Zm&gt;</symbol>
      <account encodedin="Zm">
        <docvars>
          <docvar key="as-structure-org" value="of-doublewords" />
        </docvars>
        <intro>
          <para>For the 64-bit variant: is the name of the second source scalable vector register Z0-Z15, encoded in the "Zm" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="smlslt_z_zzzi_s" symboldefcount="1">
      <symbol link="sa_imm_1">&lt;imm&gt;</symbol>
      <account encodedin="i3h:i3l">
        <docvars>
          <docvar key="as-structure-org" value="of-words" />
        </docvars>
        <intro>
          <para>For the 32-bit variant: is the element index, in the range 0 to 7, encoded in the "i3h:i3l" fields.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="smlslt_z_zzzi_d" symboldefcount="2">
      <symbol link="sa_imm">&lt;imm&gt;</symbol>
      <account encodedin="i2h:i2l">
        <docvars>
          <docvar key="as-structure-org" value="of-doublewords" />
        </docvars>
        <intro>
          <para>For the 64-bit variant: is the element index, in the range 0 to 3, encoded in the "i2h:i2l" fields.</para>
        </intro>
      </account>
    </explanation>
  </explanations>
  <ps_section howmany="1">
    <ps name="SMLSLT-Z.ZZZi-S" mylink="execute" enclabels="" sections="1" secttype="Operation">
      <pstext mayhavelinks="1" section="Execute" rep_section="execute"><a link="impl-aarch64.CheckSVEEnabled.0" file="shared_pseudocode.xml" hover="function: CheckSVEEnabled()">CheckSVEEnabled</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;
constant integer elements = VL DIV (2 * esize);
constant integer eltspersegment = 128 DIV (2 * esize);
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, 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) result = <a link="impl-aarch64.Z.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) Z[integer n, integer width]">Z</a>[da, VL];

for e = 0 to elements-1
    integer s = e - (e MOD eltspersegment);
    integer element1 = <a link="impl-shared.SInt.1" file="shared_pseudocode.xml" hover="function: integer SInt(bits(N) x)">SInt</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 + sel,   esize]);
    integer element2 = <a link="impl-shared.SInt.1" file="shared_pseudocode.xml" hover="function: integer SInt(bits(N) x)">SInt</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 + index, esize]);
    bits(2*esize) product = (element1 * element2)&lt;2*esize-1:0&gt;;
    <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, 2*esize] = <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>[result, e, 2*esize] - product;

<a link="impl-aarch64.Z.write.2" file="shared_pseudocode.xml" hover="accessor: Z[integer n, integer width] = bits(width) value">Z</a>[da, VL] = result;</pstext>
    </ps>
  </ps_section>
</instructionsection>
