12.11 Adding a new GIMPLE statement code

The first step in adding a new GIMPLE statement code, is modifying the file gimple.def, which contains all the GIMPLE codes. Then you must add a corresponding gimple subclass located in gimple.h. This in turn, will require you to add a corresponding GTY tag in gsstruct.def, and code to handle this tag in gss_for_code which is located in gimple.c.

In order for the garbage collector to know the size of the structure you created in gimple.h, you need to add a case to handle your new GIMPLE statement in gimple_size which is located in gimple.c.

You will probably want to create a function to build the new gimple statement in gimple.c. The function should be called gimple_build_new-tuple-name, and should return the new tuple as a pointer to the appropriate gimple subclass.

If your new statement requires accessors for any members or operands it may have, put simple inline accessors in gimple.h and any non-trivial accessors in gimple.c with a corresponding prototype in gimple.h.

You should add the new statement subclass to the class hierarchy diagram in gimple.texi.