smaxp

SMAXP <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, <Zm>.<T>

Signed Maximum Pairwise.

Pseudocode Operation

No pseudocode available.

Encoding

Binary Layout

01000100

31:24

size

23:22

010

21:19

101

15:13

12:10

9:5

Zdn

4:0

Format SVE2

Opcode 0x4414A000

Extension SVE2

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0x0E20A400	SMAXP <Vd>.<T>, <Vn>.<T>, <Vm>.<T>		A64		0 \| Q \| 0 \| 01110 \| size \| 1 \| Rm \| 1010 \| 0 \| 1 \| Rn \| Rd
0x4414A000	SMAXP <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, <Zm>.<T>		A64		01000100 \| size \| 010 \| 1 \| 0 \| 0 \| 101 \| Pg \| Zm \| Zdn

Description

Compute the maximum value of each pair of adjacent signed integer elements within each source vector, and interleave the results from corresponding lanes. The interleaved result values are destructively placed in the first source vector.

Operation

CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
constant integer elements = VL DIV esize;
bits(PL) mask = P[g, PL];
bits(VL) operand1 = Z[dn, VL];
bits(VL) operand2 = if AnyActiveElement(mask, esize) then Z[m, VL] else Zeros(VL);
bits(VL) result;
integer element1;
integer element2;

for e = 0 to elements-1
    if !ActivePredicateElement(mask, e, esize) then
        Elem[result, e, esize] = Elem[operand1, e, esize];
    else
        if IsEven(e) then
            element1 = SInt(Elem[operand1, e + 0, esize]);
            element2 = SInt(Elem[operand1, e + 1, esize]);
        else
            element1 = SInt(Elem[operand2, e - 1, esize]);
            element2 = SInt(Elem[operand2, e + 0, esize]);
        integer res = Max(element1, element2);
        Elem[result, e, esize] = res<esize-1:0>;

Z[dn, VL] = result;