The called procedure is expected to save and restore all local and input registers (10 through 17 and i0 through i7). The calling procedure can assume that only these registers are preserved across the call. The function result is general ally in o0, f0, or both f0 and f1, or the result temporary provided by the caller, depending on the result data type. For more information, see the section Sun Sparc Function Result Conventions.
A called procedure is responsible for establishing a new stack frame for itself and saving and restoring all local and input registers. This is accomplished by a SAVE instruction. Before returning, the called procedure must store any function result value, restore all local and input registers, and adjust the stack frame. This is accomplished by a load of i0, f0, or both f0 and f1, or a store to a result temporary and a RESTORE instruction.