__lsx_vsrar_d

LSX intrinsic · group: Shift

Synopsis

__m128i __lsx_vsrar_d (__m128i a, __m128i b)
#include <lsxintrin.h>
Instruction: vsrar.d vr, vr, vr
CPU Flags: LSX

Description

Arithmetic right shift with rounding each signed 64-bit element in a by the corresponding element of b modulo 64, store the result in dst.

Operation

for (int i = 0; i < 2; i++) {
  if ((b.dword[i] & 0x3f) == 0) {
    dst.dword[i] = a.dword[i];
  } else {
    dst.dword[i] = ((s64)a.dword[i] >> (b.dword[i] & 0x3f)) +
                   (((s64)a.dword[i] >> ((b.dword[i] & 0x3f) - 1)) & 0x1);
  }
}

Tested on real machine.

Latency and Throughput

CPU	µarch	Latency	Throughput (IPC)
3C5000	LA464	3	2
3A6000	LA664	3	2
3C6000	LA664	3	2
2K1000LA	LA264	2	1
2K3000	LA364E	2	1

---

All intrinsics in alphabetical order