<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type="text/xsl" encoding="UTF-8" href="iform.xsl" version="1.0"?>
<!DOCTYPE instructionsection PUBLIC "-//ARM//DTD instructionsection //EN" "iform-p.dtd">
<!-- Copyright (c) 2010-2022 Arm Limited or its affiliates. All rights reserved. -->
<!-- This document is Non-Confidential. This document may only be used and distributed in accordance with the terms of the agreement entered into by Arm and the party that Arm delivered this document to. -->

<instructionsection id="smaxp_z_p_zz" title="SMAXP" type="instruction">
  <docvars>
    <docvar key="instr-class" value="sve2" />
    <docvar key="isa" value="A64" />
    <docvar key="mnemonic" value="SMAXP" />
  </docvars>
  <heading>SMAXP</heading>
  <desc>
    <brief>Signed maximum pairwise</brief>
    <description>
      <para>Compute the maximum value of each pair of adjacent signed integer elements within each source vector, and interleave the results from corresponding lanes. The interleaved result values are destructively placed in the first source vector.</para>
    </description>
    <status>Green</status>
    <predicated>True</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>
    <iclass name="SVE2" oneof="1" id="iclass_sve2" no_encodings="1" isa="A64">
      <docvars>
        <docvar key="instr-class" value="sve2" />
        <docvar key="isa" value="A64" />
        <docvar key="mnemonic" value="SMAXP" />
      </docvars>
      <iclassintro count="1"></iclassintro>
      <regdiagram form="32" psname="SMAXP-Z.P.ZZ-_" 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" width="2" name="size" usename="1">
          <c colspan="2"></c>
        </box>
        <box hibit="21" width="3" settings="3">
          <c>0</c>
          <c>1</c>
          <c>0</c>
        </box>
        <box hibit="18" name="opc&lt;1&gt;" settings="1">
          <c>1</c>
        </box>
        <box hibit="17" name="opc&lt;0&gt;" settings="1">
          <c>0</c>
        </box>
        <box hibit="16" name="U" usename="1" settings="1">
          <c>0</c>
        </box>
        <box hibit="15" width="3" settings="3">
          <c>1</c>
          <c>0</c>
          <c>1</c>
        </box>
        <box hibit="12" width="3" name="Pg" usename="1">
          <c colspan="3"></c>
        </box>
        <box hibit="9" width="5" name="Zm" usename="1">
          <c colspan="5"></c>
        </box>
        <box hibit="4" width="5" name="Zdn" usename="1">
          <c colspan="5"></c>
        </box>
      </regdiagram>
      <encoding name="smaxp_z_p_zz_" oneofinclass="1" oneof="1" label="">
        <docvars>
          <docvar key="instr-class" value="sve2" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="SMAXP" />
        </docvars>
        <asmtemplate><text>SMAXP   </text><a link="sa_zdn" hover="First source and destination scalable vector register (field &quot;Zdn&quot;)">&lt;Zdn&gt;</a><text>.</text><a link="sa_t" hover="Size specifier (field &quot;size&quot;) [B,D,H,S]">&lt;T&gt;</a><text>, </text><a link="sa_pg" hover="Governing scalable predicate register P0-P7 (field &quot;Pg&quot;)">&lt;Pg&gt;</a><text>/M, </text><a link="sa_zdn" hover="First source and destination scalable vector register (field &quot;Zdn&quot;)">&lt;Zdn&gt;</a><text>.</text><a link="sa_t" hover="Size specifier (field &quot;size&quot;) [B,D,H,S]">&lt;T&gt;</a><text>, </text><a link="sa_zm" hover="Second source scalable vector register (field &quot;Zm&quot;)">&lt;Zm&gt;</a><text>.</text><a link="sa_t" hover="Size specifier (field &quot;size&quot;) [B,D,H,S]">&lt;T&gt;</a></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="SMAXP-Z.P.ZZ-_" mylink="SMAXP-Z.P.ZZ-_" 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 = 8 &lt;&lt; <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(size);
integer g = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Pg);
integer m = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zm);
integer dn = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(Zdn);</pstext>
        </ps>
      </ps_section>
    </iclass>
  </classes>
  <explanations scope="all">
    <explanation enclist="smaxp_z_p_zz_" symboldefcount="1">
      <symbol link="sa_zdn">&lt;Zdn&gt;</symbol>
      <account encodedin="Zdn">
        <intro>
          <para>Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="smaxp_z_p_zz_" symboldefcount="1">
      <symbol link="sa_t">&lt;T&gt;</symbol>
      <definition encodedin="size">
        <intro>Is the size specifier, </intro>
        <table class="valuetable">
          <tgroup cols="2">
            <thead>
              <row>
                <entry class="bitfield">size</entry>
                <entry class="symbol">&lt;T&gt;</entry>
              </row>
            </thead>
            <tbody>
              <row>
                <entry class="bitfield">00</entry>
                <entry class="symbol">B</entry>
              </row>
              <row>
                <entry class="bitfield">01</entry>
                <entry class="symbol">H</entry>
              </row>
              <row>
                <entry class="bitfield">10</entry>
                <entry class="symbol">S</entry>
              </row>
              <row>
                <entry class="bitfield">11</entry>
                <entry class="symbol">D</entry>
              </row>
            </tbody>
          </tgroup>
        </table>
      </definition>
    </explanation>
    <explanation enclist="smaxp_z_p_zz_" 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="smaxp_z_p_zz_" 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, encoded in the "Zm" field.</para>
        </intro>
      </account>
    </explanation>
  </explanations>
  <ps_section howmany="1">
    <ps name="SMAXP-Z.P.ZZ-_" 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 esize;
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];
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>[dn, VL];
bits(VL) operand2 = 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 <a link="impl-aarch64.Z.read.2" file="shared_pseudocode.xml" hover="accessor: bits(width) Z[integer n, integer width]">Z</a>[m, VL] else <a link="impl-shared.Zeros.1" file="shared_pseudocode.xml" hover="function: bits(N) Zeros(integer N)">Zeros</a>(VL);
bits(VL) result;
integer element1;
integer element2;

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
        <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.Elem.read.3" file="shared_pseudocode.xml" hover="accessor: bits(size) Elem[bits(N) vector, integer e, integer size]">Elem</a>[operand1, e, esize];
    else
        if <a link="impl-aarch64.IsEven.1" file="shared_pseudocode.xml" hover="function: boolean IsEven(integer val)">IsEven</a>(e) then
            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, e + 0, esize]);
            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>[operand1, e + 1, esize]);
        else
            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>[operand2, e - 1, esize]);
            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, e + 0, esize]);
        integer res = <a link="impl-shared.Max.2" file="shared_pseudocode.xml" hover="function: integer Max(integer a, integer b)">Max</a>(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] = res&lt;esize-1:0&gt;;

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