smearx
Find the first one in a bool vector, shift it one to the right and set all remaining elments to one too.
The main purpose of this operation is to facilitate vectorization of loops, do-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 | 0 | 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. Since the rightmost value would be shifted out, a second result value is returned to the belt which holds that value. It always must be checked too for the exit condition.
related operations: smeari, left, mask
| 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
