6.33.15 M32R/D Function Attributes

These function attributes are supported by the M32R/D back end:

interrupt

Use this attribute to indicate that the specified function is an interrupt handler. The compiler generates function entry and exit sequences suitable for use in an interrupt handler when this attribute is present.

model (model-name)

On the M32R/D, use this attribute to set the addressability of an object, and of the code generated for a function. The identifier model-name is one of small, medium, or large, representing each of the code models.

Small model objects live in the lower 16MB of memory (so that their addresses can be loaded with the ld24 instruction), and are callable with the bl instruction.

Medium model objects may live anywhere in the 32-bit address space (the compiler generates seth/add3 instructions to load their addresses), and are callable with the bl instruction.

Large model objects may live anywhere in the 32-bit address space (the compiler generates seth/add3 instructions to load their addresses), and may not be reachable with the bl instruction (the compiler generates the much slower seth/add3/jl instruction sequence).