#### 8.19.4 Assembler Directives

The 68HC11 and 68HC12 version of `as` have the following specific assembler directives:

`.relax`
  The relax directive is used by the GNU Compiler to emit a specific relocation to mark a group of instructions for linker relaxation. The sequence of instructions within the group must be known to the linker so that relaxation can be performed.
`.mode [mshort|mlong|mshort-double|mlong-double]`
  This directive specifies the ABI. It overrides the -mshort, -mlong, -mshort-double and -mlong-double options.
`.far` symbol
  This directive marks the symbol as a far symbol meaning that it uses a call/rtc calling convention as opposed to jsr/rts. During a final link, the linker will identify references to the far symbol and will verify the proper calling convention.
`.interrupt` symbol
  This directive marks the symbol as an interrupt entry point. This information is then used by the debugger to correctly unwind the frame across interrupts.
`.xrefb` symbol
  This directive is defined for compatibility with the Specification for Motorola 8 and 16-Bit Assembly Language Input Standard and is ignored.