smeari

speculable  exu stream  exu block  compute phase   operation   in the logical value domain  

native on: all

Find the first one in a bool vector and set all remaining elments to one too.

The main purpose of this operation is to facilitate vectorization of loops, while loops in particular. It allows you to treat conditions created in a SIMD as exit conditions in a loop, since the first occurrence of a true value applies to all the remaining values and would be iterations.

0

0

0

0

1

0

0

0

becomes

0

0

0

0

1

1

1

1

which then can be used in pick operations or other vector operations, yet the exit condition is preserved for all elements that would not be in the iteration anymore if it wasn't vectorized.

related operations: smearx, left, mask

---

smeari(op vs) → op r0

operands: like Shuffle [xn:x]

encoding: smeari(op vs)

Core	In Slots	Latencies
Tin	E0	1
Copper	E0	1
Silver	E0 E1 E2 E3	1
Gold	E0	1

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