__lsx_vavg_d
LSX intrinsic · group: Integer Computation
Synopsis
__m128i __lsx_vavg_d (__m128i a, __m128i b)
#include <lsxintrin.h>
Instruction: vavg.d vr, vr, vr
CPU Flags: LSX
Description
Compute the average (rounded towards negative infinity) of corresponding signed 64-bit elements in a and b, save the result in dst.
Operation
for (int i = 0; i < 2; i++) {
dst.dword[i] = ((s64)a.dword[i] >> 1) + ((s64)b.dword[i] >> 1) +
((a.dword[i] & b.dword[i]) & 1);
}
Tested on real machine.
Latency and Throughput
| CPU | µarch | Latency | Throughput (IPC) |
|---|---|---|---|
| 3C5000 | LA464 | 2 | 2 |
| 3A6000 | LA664 | 2 | 4 |
| 3C6000 | LA664 | 2 | 4 |
| 2K1000LA | LA264 | 2 | 1 |
| 2K3000 | LA364E | 2 | 1 |