GCSPOPX

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GCSPOPX, Guarded Control Stack Pop exception return record

Purpose

Loads an exception return record from the location indicated by the current Guarded Control Stack Pointer register, checks that the record is a Guarded Control Stack exception return record, and increments the current Guarded Control Stack Pointer register by the size of a Guarded Control Stack exception return record.

Configuration

This instruction is present only when FEAT_GCS is implemented and FEAT_AA64 is implemented. Otherwise, direct accesses to GCSPOPX are UNDEFINED.

Attributes

Field descriptions

Executing GCSPOPX

Rt should be encoded as 0b11111. If the Rt field is not set to 0b11111, it is CONSTRAINED UNPREDICTABLE whether:

The instruction is UNDEFINED.
The instruction behaves as if the Rt field is set to 0b11111.

This system instruction is an alias of the SYS instruction.

Accesses to this instruction use the following encodings in the System instruction encoding space:

GCSPOPX

op0	op1	CRn	CRm	op2
0b01	0b000	0b0111	0b0111	0b110

if !(IsFeatureImplemented(FEAT_GCS) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if GCSEnabled(EL1) then GCSPOPX(); end; elsif PSTATE.EL == EL2 then if GCSEnabled(EL2) then GCSPOPX(); end; elsif PSTATE.EL == EL3 then if GCSEnabled(EL3) then GCSPOPX(); end; end;