__lasx_xvsrani_w_d
LASX intrinsic · group: Shift
Synopsis
__m256i __lasx_xvsrani_w_d (__m256i a, __m256i b, imm0_63 imm)
#include <lasxintrin.h>
Instruction: xvsrani.w.d xr, xr, imm
CPU Flags: LASX
Description
Arithmetic right shift the signed 64-bit elements in a and b by imm, write the lower 32 bits of the shifted result into the lower half of each 128-bit lane of dst, and zero the upper half.
Operation
for (int i = 0; i < 4; i++) {
dst.word[i] = (i < 2) ? (s32)((s64)b.dword[i] >> imm)
: (s32)((s64)a.dword[i - 2] >> imm);
}
for (int i = 4; i < 8; i++) {
dst.word[i] = (i < 6) ? (s32)((s64)b.dword[i - 2] >> imm)
: (s32)((s64)a.dword[i - 4] >> imm);
}
Tested on real machine.
Latency and Throughput
| CPU | µarch | Latency | Throughput (IPC) |
|---|---|---|---|
| 3C5000 | LA464 | 4 | 1 |
| 3A6000 | LA664 | 4 | 2 |
| 3C6000 | LA664 | 4 | 2 |