__lsx_vmulwod_w_hu
LSX intrinsic · group: Integer Computation
Synopsis
__m128i __lsx_vmulwod_w_hu (__m128i a, __m128i b)
#include <lsxintrin.h>
Instruction: vmulwod.w.hu vr, vr, vr
CPU Flags: LSX
Description
Multiply the odd-positioned unsigned 16-bit elements in a and the corresponding unsigned 16-bit elements in b, extending both to 32-bit, and save the 32-bit result in dst.
Operation
for (int i = 0; i < 4; i++) {
dst.word[i] = (u32)(u16)a.half[2 * i + 1] * (u32)(u16)b.half[2 * i + 1];
}
// Expands to:
if (0) {
dst.word[0] = ((u32)((u16)a.half[1])) * ((u32)((u16)b.half[1]));
dst.word[1] = ((u32)((u16)a.half[3])) * ((u32)((u16)b.half[3]));
dst.word[2] = ((u32)((u16)a.half[5])) * ((u32)((u16)b.half[5]));
dst.word[3] = ((u32)((u16)a.half[7])) * ((u32)((u16)b.half[7]));
}
Tested on real machine.
Latency and Throughput
| CPU | µarch | Latency | Throughput (IPC) |
|---|---|---|---|
| 3C5000 | LA464 | 4 | 2 |
| 3A6000 | LA664 | 4 | 2 |
| 3C6000 | LA664 | 4 | 2 |
| 2K1000LA | LA264 | 4 | 1 |
| 2K3000 | LA364E | 4 | 1 |