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GCSPOPM

GCSPOPM, Guarded Control Stack Pop

The GCSPOPM characteristics are:

Purpose

Loads the 64-bit doubleword that is pointed to by the current Guarded Control Stack Pointer, writes it to the destination register, and increments the current Guarded Control Stack Pointer register by the size of a Guarded Control Stack procedure return record.

Configuration

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

Attributes

GCSPOPM is a 64-bit System instruction.

Field descriptions

63	62	61	60	59	58	57	56	55	54	53	52	51	50	49	48	47	46	45	44	43	42	41	40	39	38	37	36	35	34	33	32
31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
Output
Output

Output, bits [63:0]

Output value for Guarded Control Stack procedure return record.

Executing GCSPOPM

This system instruction is an alias of the SYSL instruction.

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

GCSPOPM {<Xt>}

op0	op1	CRn	CRm	op2
0b01	0b011	0b0111	0b0111	0b001

if !(IsFeatureImplemented(FEAT_GCS) && IsFeatureImplemented(FEAT_AA64)) then Undefined(); elsif GCSEnabled(PSTATE.EL) then X{64}(t) = GCSPOPM(); end;

2026-03-12 12:23:09, 2025-09_rel_asl1