ttest

Transaction Test

TTEST <Xd>

Tests the transaction nesting depth.

Pseudocode Operation

Xd ← TME_NESTING_DEPTH
Xd[31:0] ← TME_STATE_AND_FAILURE_INFO
Xd[63:32] ← 0

Example

TTEST x0

Encoding

Binary Layout

1101010100100

31:19

011

18:16

0011

15:12

0001

11:8

011

7:5

Rt

4:0

 

Format System

Opcode 0xD5233160

Extension TME (Transactional)

Operands

• Xd
  Destination 64-bit integer register

Related

More in TME (Transactional)

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0xD5233160	TTEST <Xt>		A64		1101010100100 | 011 | 0011 | 0001 | 011 | Rt

Description

This instruction writes the depth of the transaction to the destination register, or the value 0 otherwise.

Operation

if !IsTMEEnabled() then UNDEFINED;

X[t, 64] = (TSTATE.depth)<63:0>;