fmaf

realizing  exu stream  exu block  compute phase   operation   in the binary floating point value domain  

native on: Silver Gold

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

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fmaf(f x, f y, f z) → f r0

operands: like Addf [ff:f]

Returns x*y+z on the belt.

encoding: fmaf(f x) , exuArgs(op arg0, op arg1)

Core	In Slots	Latencies
Silver	E0 E1	w,w:w=6 wv,wv:wv=6 d,d:d=7 dv,dv:dv=7 q,q:q=8 qv,qv:qv=8
Gold	E0 E1 E2 E3	w,w:w=6 wv,wv:wv=6 d,d:d=7 dv,dv:dv=7 q,q:q=8 qv,qv:qv=8

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fmaf(f x, f y, f z, f w) → f r0, f r1

operands: like Fmasf [ff:f]

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: fmaf(f x, f y) , exuArgs(op arg0, op arg1)

Core	In Slots	Latencies
Silver	E0	w,w:w,w=6,6 wv,wv:wv,wv=6,6 d,d:d,d=7,7 dv,dv:dv,dv=7,7 q,q:q,q=8,8 qv,qv:qv,qv=8,8
Gold	E0 E2	w,w:w,w=6,6 wv,wv:wv,wv=6,6 d,d:d,d=7,7 dv,dv:dv,dv=7,7 q,q:q,q=8,8 qv,qv:qv,qv=8,8