EOR (immediate)

Bitwise exclusive-OR with immediate (unpredicated)

This instruction performs a bitwise exclusive-OR between an immediate and each 64-bit element of the source vector, and destructively places the results in the corresponding elements of the source vector. The immediate is a 64-bit value consisting of a single run of ones or zeros repeating every 2, 4, 8, 16, 32 or 64 bits. This instruction is unpredicated.

This instruction is used by the pseudo-instruction EON.

SVE
(FEAT_SVE || FEAT_SME)

313029282726252423222120191817161514131211109876543210
00000101010000imm13Zdn
opc

Encoding

EOR <Zdn>.<T>, <Zdn>.<T>, #<const>

Decode for this encoding

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; let dn : integer = UInt(Zdn); var imm : bits(64); (imm, -) = DecodeBitMasks{64}(imm13[12], imm13[5:0], imm13[11:6], TRUE);

Assembler Symbols

<Zdn>

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

<T>

Is the size specifier, encoded in imm13:

imm13 <T>
0xxxxxx0xxxxx S
0xxxxxx10xxxx H
0xxxxxx110xxx B
0xxxxxx1110xx B
0xxxxxx11110x B
0xxxxxx11111x RESERVED
1xxxxxxxxxxxx D
<const>

Is a 64, 32, 16 or 8-bit bitmask consisting of replicated 2, 4, 8, 16, 32 or 64 bit fields, each field containing a rotated run of non-zero bits, encoded in the "imm13" field.

Operation

CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV 64; let operand : bits(VL) = Z{}(dn); var result : bits(VL); for e = 0 to elements-1 do let element1 : bits(64) = operand[e*:64]; result[e*:64] = element1 XOR imm; 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

Copyright © 2010-2026 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.