s390 Instruction Marker - Using as
Description: Using as

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##### 9.35.3.7 Instruction Marker

The thread local storage instruction markers are used by the linker to perform code optimization.

`:tls_load`
  The :tls_load marker is used to flag the load instruction in the initial exec TLS model that retrieves the offset from the thread pointer to a thread local storage variable from the GOT.
`:tls_gdcall`
  The :tls_gdcall marker is used to flag the branch-and-save instruction to the __tls_get_offset function in the global dynamic TLS model.
`:tls_ldcall`
  The :tls_ldcall marker is used to flag the branch-and-save instruction to the __tls_get_offset function in the local dynamic TLS model.

For more information about the thread local storage instruction marker and the linker optimizations see the ELF extension documentation ‘`ELF Handling For Thread-Local Storage`’.