__lsx_vextrins_d
LSX intrinsic · group: Misc
Synopsis
__m128i __lsx_vextrins_d (__m128i a, __m128i b, imm0_255 imm)
#include <lsxintrin.h>
Instruction: vextrins.d vr, vr, imm
CPU Flags: LSX
Description
Copy the 64-bit element of b selected by imm[0] into the element of a selected by imm[4]; other elements remain unchanged.
Operation
for (int i = 0; i < 2; i++) {
dst.dword[i] = (i == ((imm >> 4) & 1)) ? b.dword[imm & 1] : a.dword[i];
}
// Expands to:
if (0) {
dst.dword[0] = (0 == ((imm >> 4) & 1)) ? (b.dword[imm & 1]) : (a.dword[0]);
dst.dword[1] = (1 == ((imm >> 4) & 1)) ? (b.dword[imm & 1]) : (a.dword[1]);
}
Tested on real machine.
Latency and Throughput
| CPU | µarch | Latency | Throughput (IPC) |
|---|---|---|---|
| 3C5000 | LA464 | 1 | 2 |
| 3A6000 | LA664 | 1 | 4 |
| 3C6000 | LA664 | 1 | 4 |
| 2K1000LA | LA264 | 1 | 1 |
| 2K3000 | LA364E | 1 | 1 |