XAR

Bitwise exclusive-OR and rotate right by immediate

This instruction performs a bitwise exclusive-OR between the corresponding elements of the first source vector and the second source vector, and then rotates each result element right by an immediate amount. The final results are destructively placed in the corresponding elements of the destination and first source vector. This instruction is unpredicated.

SVE2
(FEAT_SVE2 || FEAT_SME)

313029282726252423222120191817161514131211109876543210
00000100tszh1tszlimm3001101ZmZdn

Encoding

XAR <Zdn>.<T>, <Zdn>.<T>, <Zm>.<T>, #<const>

Decode for this encoding

if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; let tsize : bits(4) = tszh::tszl; if tsize == '0000' then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << HighestSetBitNZ(tsize); let m : integer = UInt(Zm); let dn : integer = UInt(Zdn); let rot : integer = (2 * esize) - UInt(tsize::imm3);

Assembler Symbols

<Zdn>

Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field.

<T>

Is the size specifier, encoded in (tszh :: tszl):

tszh tszl <T>
00 00 RESERVED
00 01 B
00 1x H
01 xx S
1x xx D
<Zm>

Is the name of the second source scalable vector register, encoded in the "Zm" field.

<const>

Is the immediate shift amount, in the range 1 to number of bits per element, encoded in "tszh:tszl:imm3".

Operation

CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV esize; let operand1 : bits(VL) = Z{}(dn); let operand2 : bits(VL) = Z{}(m); var result : bits(VL); for e = 0 to elements-1 do let element1 : bits(esize) = operand1[e*:esize]; let element2 : bits(esize) = operand2[e*:esize]; result[e*:esize] = ROR(element1 XOR element2, rot); end; Z{VL}(dn) = result;

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.

This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is CONSTRAINED UNPREDICTABLE:


2026-03_rel 2026-03-26 20:48:11

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