问题
Is there any Fortran keyword equivalent to the C "inline" keyword?
If some compiler-specific keyword exist, is there any for gfortran?
回答1:
In general, the Fortran specifications grant the compiler writers enormous scope in how to implement things, so a language-level construct that forced (or even hinted) specific optimizations would be very un-Fortran-y.
What you typically do in modern Fortran is not specify optimizations, but tell the compiler things it can use to decide what optimizations to implement. So an example is labelling a side-effect-free function or subroutine PURE, so that certain optimizations are enabled (and actually, this may make for easier inlining).
Otherwise, as @Vladimir F points out, you can use compiler options which are presecriptive in this way.
In a similar vein, it seems that CONTAINed subprogram are more aggressively inlined by gfortran, but that may or may not help.
回答2:
There is no source code statement I know of. Sometimes you can use statement functions, which are obviously inlined. Otherwise use compiler comand line options as gfortran's "-finline-functions".
来源：https://stackoverflow.com/questions/6763402/inline-keyword-gfortran