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Bitwise exclusive OR with inverted immediate (unpredicated).

Bitwise exclusive OR an inverted immediate with each 64-bit element of the source vector, and destructively place 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 is a pseudo-instruction of EOR (immediate). This means:

  • The encodings in this description are named to match the encodings of EOR (immediate).
  • The assembler syntax is used only for assembly, and is not used on disassembly.
  • The description of EOR (immediate) gives the operational pseudocode for this instruction.



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

is equivalent to

EOR <Zdn>.<T>, <Zdn>.<T>, #(-<const> - 1)

Assembler Symbols


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

<T> Is the size specifier, encoded in imm13<12>:imm13<5:0>:
imm13<12> imm13<5:0> <T>
0 0xxxxx S
0 10xxxx H
0 110xxx B
0 1110xx B
0 11110x B
0 111110 RESERVED
0 111111 RESERVED
1 xxxxxx D

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.


The description of EOR (immediate) gives the operational pseudocode for this instruction.

Operational information

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

  • The MOVPRFX instruction must be unpredicated.
  • The MOVPRFX instruction must specify the same destination register as this instruction.
  • The destination register must not refer to architectural register state referenced by any other source operand register of this instruction.