__lasx_xvmulwod_h_bu_b
LASX intrinsic · group: Integer Computation
Synopsis
__m256i __lasx_xvmulwod_h_bu_b (__m256i a, __m256i b)
#include <lasxintrin.h>
Instruction: xvmulwod.h.bu.b xr, xr, xr
CPU Flags: LASX
Description
Multiply the odd-positioned unsigned 8-bit elements in a and the corresponding signed 8-bit elements in b, extending both to 16-bit, and save the 16-bit result in dst.
Operation
for (int i = 0; i < 16; i++) {
dst.half[i] = (u16)(u8)a.byte[2 * i + 1] * (s16)(s8)b.byte[2 * i + 1];
}
// Expands to:
if (0) {
dst.half[0] = ((u16)((u8)a.byte[1])) * ((s16)((s8)b.byte[1]));
dst.half[1] = ((u16)((u8)a.byte[3])) * ((s16)((s8)b.byte[3]));
dst.half[2] = ((u16)((u8)a.byte[5])) * ((s16)((s8)b.byte[5]));
dst.half[3] = ((u16)((u8)a.byte[7])) * ((s16)((s8)b.byte[7]));
dst.half[4] = ((u16)((u8)a.byte[9])) * ((s16)((s8)b.byte[9]));
dst.half[5] = ((u16)((u8)a.byte[11])) * ((s16)((s8)b.byte[11]));
dst.half[6] = ((u16)((u8)a.byte[13])) * ((s16)((s8)b.byte[13]));
dst.half[7] = ((u16)((u8)a.byte[15])) * ((s16)((s8)b.byte[15]));
dst.half[8] = ((u16)((u8)a.byte[17])) * ((s16)((s8)b.byte[17]));
dst.half[9] = ((u16)((u8)a.byte[19])) * ((s16)((s8)b.byte[19]));
dst.half[10] = ((u16)((u8)a.byte[21])) * ((s16)((s8)b.byte[21]));
dst.half[11] = ((u16)((u8)a.byte[23])) * ((s16)((s8)b.byte[23]));
dst.half[12] = ((u16)((u8)a.byte[25])) * ((s16)((s8)b.byte[25]));
dst.half[13] = ((u16)((u8)a.byte[27])) * ((s16)((s8)b.byte[27]));
dst.half[14] = ((u16)((u8)a.byte[29])) * ((s16)((s8)b.byte[29]));
dst.half[15] = ((u16)((u8)a.byte[31])) * ((s16)((s8)b.byte[31]));
}
Tested on real machine.
Latency and Throughput
| CPU | µarch | Latency | Throughput (IPC) |
|---|---|---|---|
| 3C5000 | LA464 | 4 | 2 |
| 3A6000 | LA664 | 4 | 2 |
| 3C6000 | LA664 | 4 | 2 |