Difference between revisions of "Instruction Set/fmade"
From Mill Computing Wiki
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{{DISPLAYTITLE:fmade}} | {{DISPLAYTITLE:fmade}} | ||
| − | <div style="font-size:80%;line-height:90%;margin-bottom:2em">[[Speculation|realizing]] [[Encoding|exu stream]] [[Decode|exu block]] [[Phasing|compute phase]] operation [[Domains|in the decimal floating point value domain]] <br /> | + | <div style="font-size:80%;line-height:90%;margin-bottom:2em">[[Speculation|realizing]] [[Encoding|exu stream]] [[Decode|exu block]] [[Phasing|compute phase]] operation [[Domains|in the decimal floating point value domain]] [[Rounding|and rounds to nearest, ties toward even adjacent value]]<br /> |
'''native on:''' [[Cores/Decimal8|Decimal8]] [[Cores/Decimal16|Decimal16]] <br /> | '''native on:''' [[Cores/Decimal8|Decimal8]] [[Cores/Decimal16|Decimal16]] <br /> | ||
</div> | </div> | ||
| − | fused multiply-add | + | Decimal floating point fused multiply-add. |
| + | As usual for those, it yields a higher precision than doing it separately, and is faster too. | ||
| + | Rounds towards even. | ||
| + | |||
---- | ---- | ||
<code style="font-size:130%"><b style="color:#050">fmade</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">fmade</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> | ||
| − | <br /> | + | Returns x*y+z on the belt.<br /> |
'''encoding:''' | '''encoding:''' | ||
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<div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeFmasd|like Fmasd [dd:d]]] | <div style="font-size:80%;line-height:90%;margin-bottom:2em">'''operands:''' [[Operands#likeFmasd|like Fmasd [dd:d]]] | ||
</div> | </div> | ||
| − | <br /> | + | This is a fused multiply-add-subtract. An excellent way to make full use of all [[Functional Unit]]s in the 2 [[Slot]]s.<br /> |
| + | r<sub>0</sub> is x*y+z*w<br /> | ||
| + | r<sub>1</sub> is x*y-z*w<br /><br /> | ||
'''encoding:''' | '''encoding:''' | ||
Revision as of 18:53, 20 December 2014
realizing exu stream exu block compute phase operation in the decimal floating point value domain and rounds to nearest, ties toward even adjacent value
Decimal floating point fused multiply-add. As usual for those, it yields a higher precision than doing it separately, and is faster too. Rounds towards even.
operands: like Addd [dd:d]
Returns x*y+z on the belt.
encoding:
fmade(d x)
,
exuArgs(op arg0, op arg1)
| Core | In Slots | Latencies |
|---|---|---|
| Decimal8 | E0 E1 | d,d:d=7 dv,dv:dv=7 q,q:q=8 qv,qv:qv=8 |
| Decimal16 | E0 E1 | d,d:d=7 dv,dv:dv=7 q,q:q=8 qv,qv:qv=8 |
fmade(d x, d y, d z, d w) → d r0, d r1
operands: like Fmasd [dd:d]
This is a fused multiply-add-subtract. An excellent way to make full use of all Functional Units in the 2 Slots.
r0 is x*y+z*w
r1 is x*y-z*w
encoding:
fmade(d x, d y)
,
exuArgs(op arg0, op arg1)
| Core | In Slots | Latencies |
|---|---|---|
| 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 |
| 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 |
Instruction Set, alphabetical, Instruction Set by Category, Instruction Set, sortable, filterable
