asm macro An asm macro is the mechanism by which programs use the enhanced asm facility. The asm macros have a definition and uses. The definition includes a set of pattern/body pairs. Each pattern describes the storage modes that the actual arguments must match for the asm macro body to be expanded. The uses resemble C function calls.
The storage mode, or mode, of an asm macro argument is the compiler's idea of where the argument can be found at run-time. Examples are "in a register" or "in memory."
pattern A pattern specifies the modes for each of the arguments of an asm macro. When the modes in the pattern all match those of the use, the corresponding body is expanded.
The asm macro body, or body, is the portion of code that will be expanded by the compiler when the corresponding pattern matches. The body may contain references to the formal parameters, in which case the compiler substitutes the corresponding assembly language code.