__lasx_xvrepl128vei_b
LASX intrinsic · group: Misc
Synopsis
__m256i __lasx_xvrepl128vei_b (__m256i a, imm0_15 idx)
#include <lasxintrin.h>
Instruction: xvrepl128vei.b xr, xr, imm
CPU Flags: LASX
Description
For each 128-bit lane, repeat that lane's element idx to fill the same lane.
Operation
for (int i = 0; i < 16; i++) {
dst.byte[i] = a.byte[idx];
}
for (int i = 16; i < 32; i++) {
dst.byte[i] = a.byte[idx + 16];
}
Tested on real machine.
Latency and Throughput
| CPU | µarch | Latency | Throughput (IPC) |
|---|---|---|---|
| 3C5000 | LA464 | 1 | 2 |
| 3A6000 | LA664 | 1 | 4 |
| 3C6000 | LA664 | 1 | 4 |