Enable or disable inlining of specified routines.
Request the optimizer to inline the user–written routines appearing in a comma-separated list of function and subroutine names. Prefixing a routine name with no% disables inlining of that routine.
Inlining is an optimization technique whereby the compiler effectively replaces a subprogram reference such as a CALL or function call with the actual subprogram code itself. Inlining often provides the optimizer more opportunities to produce efficient code.
Specify %auto to enable automatic inlining at optimization levels -O4 or -O5. Automatic inlining at these optimization levels is normally turned off when explicit inlining is specified with -inline.
Specifying -xinline= without naming any functions or %auto indicates that none of the routines in the source files are to be inlined.
Example: Inline the routines xbar, zbar, vpoint:
demo% f95 -O3 -inline=xbar,zbar,vpoint *.f
Following are the restrictions; no warnings are issued:
Optimization must be -O3 or greater.
The source for the routine must be in the file being compiled, unless -xipo or–xcrossfile are also specified.
The compiler determines if actual inlining is profitable and safe.
The appearance of -inline with -O4 disables the automatic inlining that the compiler would normally perform, unless %auto is also specified. With -O4, the compilers normally try to inline all appropriate user–written subroutines and functions. Adding -inline with -O4 may degrade performance by restricting the optimizer’s inlining to only those routines in the list. In this case, use the %auto suboption to enable automatic inlining at -O4 and -O5.
demo% f95 -O4 -inline=%auto,no%zpoint *.f
In the example above, the user has enabled -O4’s automatic inlining while disabling any possible inlining of the routine zpoint() that the compiler might attempt.