-fprofile-local-exec-tls

Purpose

Enables PGO instrumentation for the access frequencies of local-exec thread local storage (TLS) variables present in your program.

Note: The option is available starting from IBM® Open XL C/C++ for AIX® 17.1.2.10.

Syntax

Read syntax diagramSkip visual syntax diagram -f profile-local-exec-tls

Defaults

-fprofile-local-exec-tls is disabled by default

Usage

When the -fprofile-local-exec-tls option is in effect, the compiler instruments the access frequencies of local-exec TLS variables present in your program. The instrumented program then generate TLS profile files with the .gv suffix in the same directory as the main profile file. The TLS profile files are to be merged using ibm-llvm-profdata merge --tls to generate a single profile file for -flocal-exec-tls-profile-use, optimizing the program to speed up local-exec TLS variable access.

Notes:
  • The -fprofile-local-exec-tls option takes effect only when -fprofile-generate is in effect.
  • To get more accurate profile data, specify -fprofile-local-exec-tls together with the -fprofile-update=atomic option.

Predefined macros

None.

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