Category
Optimization and tuning
Pragma equivalent
None.
Purpose
Performs high-order loop analysis and transformations (HOT) during optimization.
Defaults
NOHOT
In the z/OS® UNIX System Services environment, if the xlc utility flag option -O, -O2, or -O3 is specified, the default is NOHOT. If -O4 or -O5 is specified, the default is HOT.
Usage
If HOT is specified, the optimization level is forced to a level of at least 2. If a lower level is requested, it is increased to 2. If a higher level is requested, the requested value is used.
The HOT option can be specified with the debugging options TEST and DEBUG. When the HOT option is used with DEBUG, the DEBUG(NOSYMBOL) suboption is forced.
The debugging information added to the output object code when HOT is used with TEST will be at the same level as the debugging information that is added when TEST is used with OPT(2).
If -g is specified, -Wc,NOHOT is forced. See -g for more information about the options implied by the flag.
The HOT option is independent of the UNROLL command line option or pragma. The HOT option setting will be listed in the compiler listing, the IPA Link phase listing, and the end card of the output object file.
Predefined macros
None.