__lasx_xvaddwev_q_du

LASX intrinsic · group: Integer Computation

Synopsis

__m256i __lasx_xvaddwev_q_du (__m256i a, __m256i b)
#include <lasxintrin.h>
Instruction: xvaddwev.q.du xr, xr, xr
CPU Flags: LASX

Description

Add the even-positioned unsigned 64-bit elements in a and the corresponding unsigned 64-bit elements in b, extending both to 128-bit, and save the 128-bit result in dst.

Operation

for (int i = 0; i < 2; i++) {
  dst.qword[i] = (u128)(u64)a.dword[2 * i] + (u128)(u64)b.dword[2 * i];
}

// Expands to:

if (0) {
  dst.qword[0] = ((u128)((u64)a.dword[0])) + ((u128)((u64)b.dword[0]));
  dst.qword[1] = ((u128)((u64)a.dword[2])) + ((u128)((u64)b.dword[2]));
}

Tested on real machine.

Latency and Throughput

CPU µarch Latency Throughput (IPC)
3C5000 LA464 3 2
3A6000 LA664 3 2
3C6000 LA664 3 2

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