MULS.AA.LL — Signed Multiply/Subtract

Instruction Word

Slot
Inst
6
3
6
2
6
1
6
0
5
9
5
8
5
7
5
6
5
5
5
4
5
3
5
2
5
1
5
0
4
9
4
8
4
7
4
6
4
5
4
4
4
3
4
2
4
1
4
0
3
9
3
8
3
7
3
6
3
5
3
4
3
3
3
2
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9876543210
Format x24 - 24 bit(s) 0
MULS.AA.LL 011111000000 0100
s 3210
t 3210

Assembler Syntax

MULS.AA.* as, at Where * expands as follows:

MULS.AA.LL - for (half=0)

MULS.AA.HL - for (half=1)

MULS.AA.LH - for (half=2)

MULS.AA.HH - for (half=3)


C Syntax

#include <xtensa/tie/xt_MAC16.h>

extern void XT_MULS_AA_LL(unsigned ars, unsigned art);

Description

(please consult the Xtensa ® Instruction Set Architecture Reference Manual for any cross references and additional information)

MULS.AA.* performs a two's complement multiply of half of each of the address registers as and at, producing a 32-bit result. The result is sign-extended to 40 bits and subtracted from the contents of the MAC16 accumulator.

Operation

m1 ← if half0 then AR[s]31..16 else AR[s]15..0
m2 ← if half1 then AR[t]31..16 else AR[t]15..0
ACC ← ACC − (m11524||m1) \* (m21524||m2)

Exceptions

EveryInstR Group (see EveryInstR Group:)

Implementation Pipeline

In Out
ACC Mstage, ars Estage, art Estage ACC Mstage

Protos that use MULS.AA.LL

proto MULS.AA.LL { in uint32 ars, in uint32 art }{}{
MULS.AA.LL ars, art;
}