BRB -- A64

BRB

Branch record buffer

For more information, see op0 == 0b01, cache maintenance, TLB maintenance, address translation, prediction restriction, BRBE, Trace Extension, and Guarded Control Stack instructions.

This is an alias of SYS. This means:

The encodings in this description are named to match the encodings of SYS.
The description of SYS gives the operational pseudocode, any constrained unpredictable behavior, and any operational information for this instruction.

System
(FEAT_BRBE)

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
1	1	0	1	0	1	0	1	0	0	0	0	1	0	0	1	0	1	1	1	0	0	1	0	op2			Rt
										L			op1			CRn				CRm

Encoding

is equivalent to

SYS #1, C7, C2, #<op2>{, <Xt>}

and is the preferred disassembly when SysOp('001', '0111', '0010', op2) == Sys_BRB.

Assembler Symbols

<brb_op>

Is a BRB operation name, as listed for the BRB system instruction group, encoded in op2:

op2	<brb_op>	Architectural Feature	Description
100	IALL	FEAT_BRBE	For more information, see BRB IALL.
101	INJ	FEAT_BRBE	For more information, see BRB INJ.

Operation

The description of SYS gives the operational pseudocode for this instruction.

2026-03_rel 2026-03-26 20:48:11

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