Permanently Undefined generates an Undefined Instruction exception (ESR_ELx.EC = 0b000000). The encodings for UDF used in this section are defined as permanently undefined in the Armv8-A architecture.


UDF #<imm>

// The imm16 field is ignored by hardware. UNDEFINED;

Assembler Symbols


is a 16-bit unsigned immediate, in the range 0 to 65535, encoded in the "imm16" field. The PE ignores the value of this constant.

Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41

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