Difference between revisions of "Instruction Set/narrowde"

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{{DISPLAYTITLE:narrowde}}
 
{{DISPLAYTITLE:narrowde}}
 
<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; [[Rounding|and rounds to nearest, ties toward even adjacent value]]<br />
 
<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; [[Rounding|and rounds to nearest, ties toward even adjacent value]]<br />
'''native on:''' [[Cores/Decimal8|Decimal8]] [[Cores/Decimal16|Decimal16]] <br />
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'''native on:''' [[Assembly|none]]<br />
 
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----
 
----
<code style="font-size:130%"><b style="color:#050">narrowde</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">v</span>) &#8594; [[Domains#d|d]] r<sub>0</sub></code>
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<code style="font-size:130%"><b style="color:#050">narrowde</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">v1</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">v2</span>) &#8594; [[Domains#d|d]] r<sub>0</sub></code>
<div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeNarrowd|like Narrowd [dd:&#189;d]]]
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<div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeNarrowvd|like Narrowvd [DD:&#189;D]]]
 
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</div>
 
<br />
 
<br />
 
{| class="mw-collapsible mw-collapsed wikitable" data-expandtext="&#9656;" data-collapsetext="&#9662;"
 
! [[Cores|Core]] || [[Slot|In Slots]]|| [[Latency|Latencies]]
 
|-
 
| [[Cores/Decimal8/Encoding#narrowde|Decimal8]] || E0 E1 || d:w=4 q:d=5
 
|-
 
| [[Cores/Decimal16/Encoding#narrowde|Decimal16]] || E0 E1 || d:w=4 q:d=5
 
|}
 
  
 
----
 
----
<code style="font-size:130%"><b style="color:#050">narrowde</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">v1</span>, <span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">v2</span>) &#8594; [[Domains#d|d]] r<sub>0</sub></code>
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<code style="font-size:130%"><b style="color:#050">narrowde</b>(<span style="color:#009">[[Domains#d|d]]</span> <span title="belt operand from ops window">op0</span>, <i><span style="color:#009">[[Immediates#width|width]]</span> <span title="data width and vector length (exu)">width0</span></i>) &#8594; [[Domains#d|d]] r<sub>0</sub></code>
<div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeNarrowvd|like Narrowvd [DD:&#189;D]]]
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<div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeNarrowd|like Narrowd [dd:&#189;d]]]
 
</div>
 
</div>
 
<br />
 
<br />
 
{| class="mw-collapsible mw-collapsed wikitable" data-expandtext="&#9656;" data-collapsetext="&#9662;"
 
! [[Cores|Core]] || [[Slot|In Slots]]|| [[Latency|Latencies]]
 
|-
 
| [[Cores/Decimal8/Encoding#narrowde|Decimal8]] || E0 E1 || dv,dv:wv=4 qv,qv:dv=5
 
|-
 
| [[Cores/Decimal16/Encoding#narrowde|Decimal16]] || E0 E1 || dv,dv:wv=4 qv,qv:dv=5
 
|}
 
  
  
 
[[Instruction_Set|Instruction Set, alphabetical]], [[Instruction Set by Category]], [http://millcomputing.com/instructions.html?collapse=7#ops Instruction Set, sortable, filterable]
 
[[Instruction_Set|Instruction Set, alphabetical]], [[Instruction Set by Category]], [http://millcomputing.com/instructions.html?collapse=7#ops Instruction Set, sortable, filterable]

Latest revision as of 14:04, 23 February 2021

realizing  exu stream  exu block  compute phase   operation   in the decimal floating point value domain   and rounds to nearest, ties toward even adjacent value

native on: none

Half the width of a decimal float value. Rounding to nearest even.

Can produce the IEEE 754 32bit decimal float interchange format.

This is not a Speculable operation. The reason for this is the impossibility to fit all of the NaR payload into values smaller than 32bit. Nominally this would only require the narrowing of 32bit values to be not speculable, but for simplicity reasons in hardware and compiler this is not so. If narrowing should prove a big bottleneck this can be revisited.


narrowde(d v1, d v2) → d r0

operands: like Narrowvd [DD:½D]



narrowde(d op0, width width0) → d r0

operands: like Narrowd [dd:½d]



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