3.4.10. CLREX

Clear Exclusive.

Syntax

CLREX{cond}

Where:

cond

Is an optional condition code. See Conditional execution.

Operation

Use CLREX to make the next STREX, STREXB, or STREXH instruction write 1 to its destination register and fail to perform the store. CLREX enables compatibility with other Arm Cortex processors that have to force the failure of the store exclusive if the exception occurs between a load exclusive instruction and the matching store exclusive instruction in a synchronization operation. In Cortex-M processors, the local exclusive access monitor clears automatically on an exception boundary, so exception handlers using CLREX are optional.

See Synchronization primitives for more information.

Condition flags

This instruction does not change the flags.

Examples

CLREX 

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