GCSPUSHX, Guarded Control Stack Push exception return record

Executing GCSPUSHX

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.

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

op0	op1	CRn	CRm	op2
0b01	0b000	0b0111	0b0111	0b100

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if IsFeatureImplemented(FEAT_GCS) && GetCurrentEXLOCKEN() && !Halted() && PSTATE.EXLOCK == '0' then EXLOCKException(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGITR_EL2.nGCSEPP == '0' then AArch64.SystemAccessTrap(EL2, 0x18); else GCSPUSHX(); elsif PSTATE.EL == EL2 then if IsFeatureImplemented(FEAT_GCS) && GetCurrentEXLOCKEN() && !Halted() && PSTATE.EXLOCK == '0' then EXLOCKException(); else GCSPUSHX(); elsif PSTATE.EL == EL3 then if IsFeatureImplemented(FEAT_GCS) && GetCurrentEXLOCKEN() && !Halted() && PSTATE.EXLOCK == '0' then EXLOCKException(); else GCSPUSHX();