Difference between revisions of "Instruction Set/fmad"

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(Created page with "{{DISPLAYTITLE:fmad}} <div style="font-size:80%;line-height:90%;margin-bottom:2em">realizing  exu stream  exu block...")
 
 
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{{DISPLAYTITLE:fmad}}
 
{{DISPLAYTITLE:fmad}}
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<div style="font-size:80%;line-height:90%;margin-bottom:2em">[[Speculation|realizing]]&nbsp;&nbsp;[[Encoding|exu stream]]&nbsp;&nbsp;[[Decode|exu block]]&nbsp;&nbsp;[[Phasing|compute phase]]&nbsp;&nbsp; operation&nbsp;&nbsp; [[Domains|in the decimal floating point value domain]]&nbsp;&nbsp;<br />
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<div style="font-size:80%;line-height:90%;margin-bottom:2em">[[Speculation|speculable]]&nbsp;&nbsp;[[Encoding|exu stream]]&nbsp;&nbsp;[[Decode|exu block]]&nbsp;&nbsp;[[Phasing|compute phase]]&nbsp;&nbsp; operation&nbsp;&nbsp; [[Domains|in the decimal floating point value domain]]&nbsp;&nbsp; [[Rounding|and rounds use current dynamic rounding mode]]<br />
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'''native on:''' [[Cores/Decimal8|Decimal8]] [[Cores/Decimal16|Decimal16]] <br />
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'''native on:''' [[Assembly|none]]<br />
 
</div>
 
</div>
  
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fused multiply-add or -add/subtract
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Decimal floating point fused multiply-add.
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As usual for those, it yields a higher precision than doing it separately, and is faster too.
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Uses current rounding behaviour.
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----
 
----
 
<code style="font-size:130%"><b style="color:#050">fmad</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">x</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">y</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops  
 
<code style="font-size:130%"><b style="color:#050">fmad</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">x</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">y</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops  
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<div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeAddd|like Addd [dd:d]]]
 
<div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeAddd|like Addd [dd:d]]]
 
</div>
 
</div>
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<br />
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Returns x*y+z on the belt.<br />
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'''encoding:'''
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<code style="font-size:100%"><b style="color:#050">fmad</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">x</span>)</code>
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,
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<code style="font-size:100%"><b style="color:#050">exuArgs</b>(<span style="color:#009">[[Domains#op|op]]</span> <span title="belt operand from ops window">arg0</span>, <span style="color:#009">[[Domains#op|op]]</span> <span title="belt operand from ops window">arg1</span>)</code>
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<br />
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−
 
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{| class="mw-collapsible mw-collapsed wikitable" data-expandtext="&#9656;" data-collapsetext="&#9662;"
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! [[Cores|Core]] || [[Slot|In Slots]]|| [[Latency|Latencies]]
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−
|-
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| [[Cores/Decimal8/Encoding#965|Decimal8]] || E0 E1 || d,d:d=7 dv,dv:dv=7 q,q:q=8 qv,qv:qv=8
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−
|-
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| [[Cores/Decimal16/Encoding#965|Decimal16]] || E0 E1 || d,d:d=7 dv,dv:dv=7 q,q:q=8 qv,qv:qv=8
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−
|}
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−
 
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----
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<code style="font-size:130%"><b style="color:#050">fmad</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">x</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">y</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops
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            window">z</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">w</span>) &#8594; [[Domains#d|d]] r<sub>0</sub>, [[Domains#d|d]] r<sub>1</sub></code>
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<div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeFmasd|like Fmasd [dd:d]]]
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</div>
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<br />
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'''encoding:'''
 
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<code style="font-size:100%"><b style="color:#050">fmad</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">x</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">y</span>)</code>
 
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,
 
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<code style="font-size:100%"><b style="color:#050">exuArgs</b>(<span style="color:#009">[[Domains#op|op]]</span> <span title="belt operand from ops window">arg0</span>, <span style="color:#009">[[Domains#op|op]]</span> <span title="belt operand from ops window">arg1</span>)</code>
 
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<br />
 
  
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{| class="mw-collapsible mw-collapsed wikitable" data-expandtext="&#9656;" data-collapsetext="&#9662;"
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[[Instruction_Set|Instruction Set, alphabetical]], [[Instruction Set by Category]], [http://millcomputing.com/instructions.html?collapse=7#ops Instruction Set, sortable, filterable]
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! [[Cores|Core]] || [[Slot|In Slots]]|| [[Latency|Latencies]]
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−
|-
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| [[Cores/Decimal8/Encoding#964|Decimal8]] || E0 || d,d:d,d=7,7 dv,dv:dv,dv=7,7 q,q:q,q=8,8 qv,qv:qv,qv=8,8
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−
|-
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| [[Cores/Decimal16/Encoding#964|Decimal16]] || E0 || d,d:d,d=7,7 dv,dv:dv,dv=7,7 q,q:q,q=8,8 qv,qv:qv,qv=8,8
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−
|}
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Latest revision as of 14:10, 23 February 2021

speculable  exu stream  exu block  compute phase   operation   in the decimal floating point value domain   and rounds use current dynamic rounding mode

native on: none

Decimal floating point fused multiply-add. As usual for those, it yields a higher precision than doing it separately, and is faster too. Uses current rounding behaviour.

fmad(d x, d y, d z) → d r0

operands: like Addd [dd:d]

Returns x*y+z on the belt.


Instruction Set, alphabetical, Instruction Set by Category, Instruction Set, sortable, filterable

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