<?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="fdot_za_zzv" title="FDOT (multiple and single vector)" type="instruction">
  <docvars>
    <docvar key="instr-class" value="mortlach2" />
    <docvar key="isa" value="A64" />
    <docvar key="mnemonic" value="FDOT" />
  </docvars>
  <heading>FDOT (multiple and single vector)</heading>
  <desc>
    <brief>Multi-vector half-precision floating-point dot-product by vector</brief>
    <description>
      <para>The instruction operates on two or four ZA single-vector groups.</para>
      <para>The instruction computes the fused sum-of-products of a pair of half-precision floating-point values held in the corresponding 32-bit elements of the two or four first source vectors and the second source vector, without intermediate rounding. The single-precision sum-of-products results are destructively added to the corresponding single-precision elements of the two or four ZA single-vector groups. 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 follows SME ZA-targeting floating-point behaviors.</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="FDOT" />
        <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="FDOT-ZA.ZZV-2x1">
        <box hibit="31" width="9" settings="9">
          <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>
        </box>
        <box hibit="22" name="op" settings="1">
          <c>0</c>
        </box>
        <box hibit="21" width="2" settings="2">
          <c>1</c>
          <c>0</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" width="3" settings="3">
          <c>1</c>
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="9" width="5" name="Zn" usename="1">
          <c colspan="5"></c>
        </box>
        <box hibit="4" width="2" name="opc2" settings="2">
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="2" width="3" name="off3" usename="1">
          <c colspan="3"></c>
        </box>
      </regdiagram>
      <encoding name="fdot_za_zzv_2x1" oneofinclass="1" oneof="2" label="">
        <docvars>
          <docvar key="instr-class" value="mortlach2" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="FDOT" />
          <docvar key="sme-multireg" value="sme-vgx2-single" />
        </docvars>
        <asmtemplate><text>FDOT    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, encoded as &quot;Zn&quot; (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></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="FDOT-ZA.ZZV-2x1" mylink="FDOT-ZA.ZZV-2x1" 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);
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>('0':Zm);
integer offset = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(off3);
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="FDOT" />
        <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="FDOT-ZA.ZZV-4x1">
        <box hibit="31" width="9" settings="9">
          <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>
        </box>
        <box hibit="22" name="op" settings="1">
          <c>0</c>
        </box>
        <box hibit="21" width="2" settings="2">
          <c>1</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" width="3" settings="3">
          <c>1</c>
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="9" width="5" name="Zn" usename="1">
          <c colspan="5"></c>
        </box>
        <box hibit="4" width="2" name="opc2" settings="2">
          <c>0</c>
          <c>0</c>
        </box>
        <box hibit="2" width="3" name="off3" usename="1">
          <c colspan="3"></c>
        </box>
      </regdiagram>
      <encoding name="fdot_za_zzv_4x1" oneofinclass="1" oneof="2" label="">
        <docvars>
          <docvar key="instr-class" value="mortlach2" />
          <docvar key="isa" value="A64" />
          <docvar key="mnemonic" value="FDOT" />
          <docvar key="sme-multireg" value="sme-vgx4-single" />
        </docvars>
        <asmtemplate><text>FDOT    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" hover="First scalable vector register of a multi-vector sequence, encoded as &quot;Zn&quot; (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></asmtemplate>
      </encoding>
      <ps_section howmany="1">
        <ps name="FDOT-ZA.ZZV-4x1" mylink="FDOT-ZA.ZZV-4x1" 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);
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>('0':Zm);
integer offset = <a link="impl-shared.UInt.1" file="shared_pseudocode.xml" hover="function: integer UInt(bits(N) x)">UInt</a>(off3);
constant integer nreg = 4;</pstext>
        </ps>
      </ps_section>
    </iclass>
  </classes>
  <explanations scope="all">
    <explanation enclist="fdot_za_zzv_2x1, fdot_za_zzv_4x1" 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="fdot_za_zzv_2x1, fdot_za_zzv_4x1" 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="fdot_za_zzv_2x1, fdot_za_zzv_4x1" symboldefcount="1">
      <symbol link="sa_zn1">&lt;Zn1&gt;</symbol>
      <account encodedin="Zn">
        <intro>
          <para>Is the name of the first scalable vector register of a multi-vector sequence, encoded as "Zn".</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="fdot_za_zzv_4x1" 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" plus 3 modulo 32.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="fdot_za_zzv_2x1" 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" plus 1 modulo 32.</para>
        </intro>
      </account>
    </explanation>
    <explanation enclist="fdot_za_zzv_2x1, fdot_za_zzv_4x1" 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>
  </explanations>
  <ps_section howmany="1">
    <ps name="FDOT-ZA.ZZV-2x1" 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 32;
integer vectors = VL DIV 8;
integer vstride = vectors DIV nreg;
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) MOD 32, 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(16) elt1_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 + 0, 16];
        bits(16) elt1_b = <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 + 1, 16];
        bits(16) elt2_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 * e + 0, 16];
        bits(16) elt2_b = <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 * e + 1, 16];
        bits(32) 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, 32];
        sum = <a link="impl-shared.FPDotAdd_ZA.6" file="shared_pseudocode.xml" hover="function: bits(N) FPDotAdd_ZA(bits(N) addend, bits(N DIV 2) op1_a, bits(N DIV 2) op1_b, bits(N DIV 2) op2_a, bits(N DIV 2) op2_b, FPCRType fpcr_in)">FPDotAdd_ZA</a>(sum, elt1_a, elt1_b, elt2_a, elt2_b, FPCR[]);
        <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, 32] = 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>
