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GCSPOPX

GCSPOPX, Guarded Control Stack Pop exception return record

The GCSPOPX characteristics are:

Purpose

Loads a GCS exception return record from the location indicated by the current GCS pointer register, checks that the record is a GCS exception return record, and increments the current GCS pointer register by the size of a GCS 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

GCSPOPX is a 64-bit System instruction.

Field descriptions

This instruction has no applicable fields.

The value in the register specified by <Xt> is ignored.

Executing GCSPOPX

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

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

op0op1CRnCRmop2
0b010b0000b01110b01110b110

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;


2026-03-26 20:27:25, 2026-03_rel

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