Sun Sparc Function Result Conventions (32-bit)

On the Sun Sparc, the result of a function is returned in one of the following four ways, depending upon the result's data type:

  1. In register o0
  2. In a temporary storage area
  3. In register f0
  4. In registers f0 and f1

On Sun Sparc systems, the calling procedure provides the temporary area and stores the address to the temporary area in the one-word hidden parameter of the user frame at %sp+0x40 prior to the call.