Module tme

Available on AArch64 or target_arch="arm64ec" only.

ARM’s Transactional Memory Extensions (TME).

This CPU feature is available on Aarch64 - A architecture profile. This feature is in the non-neon feature set. TME specific vendor documentation can be found TME Intrinsics Introduction.

The reference is ACLE Q4 2019.

ACLE has a section for TME extensions and state masks for aborts and failure codes. ARM A64 Architecture Register Datasheet also describes possible failure code scenarios.

Constants

_TMFAILURE_CNCLExperimental

Transaction executed a TCANCEL instruction

_TMFAILURE_DBGExperimental

Transaction aborted due to a debug trap.

_TMFAILURE_ERRExperimental

Transaction aborted because a non-permissible operation was attempted

_TMFAILURE_IMPExperimental

Fallback error type for any other reason

_TMFAILURE_INTExperimental

Transaction failed from interrupt

_TMFAILURE_MEMExperimental

Transaction aborted because a conflict occurred

_TMFAILURE_NESTExperimental

Transaction aborted due to transactional nesting level was exceeded

_TMFAILURE_REASONExperimental

Extraction mask for failure reason

_TMFAILURE_RTRYExperimental

Transaction retry is possible.

_TMFAILURE_SIZEExperimental

Transaction aborted due to read or write set limit was exceeded

_TMFAILURE_TRIVIALExperimental

Indicates a TRIVIAL version of TM is available

_TMSTART_SUCCESSExperimental

Transaction successfully started.

Functions

aarch64_tcancel 🔒 ^⚠

aarch64_tcommit 🔒 ^⚠

aarch64_tstart 🔒 ^⚠

aarch64_ttest 🔒 ^⚠

__tcancel^⚠Experimentaltme

Cancels the current transaction and discards all state modifications that were performed transactionally.

__tcommit^⚠Experimentaltme

Commits the current transaction. For a nested transaction, the only effect is that the transactional nesting depth is decreased. For an outer transaction, the state modifications performed transactionally are committed to the architectural state.

__tstart^⚠Experimentaltme

Starts a new transaction. When the transaction starts successfully the return value is 0. If the transaction fails, all state modifications are discarded and a cause of the failure is encoded in the return value.

__ttest^⚠Experimentaltme

Tests if executing inside a transaction. If no transaction is currently executing, the return value is 0. Otherwise, this intrinsic returns the depth of the transaction.