CS 2734 Computer Organization II

• Review Sparc Registers (see the table on page 44 of Paul):
  • g registers are the global registers.
  • o registers are for passing parameters to called functions.
  • l registers for local variables.
  • i registers for incoming function arguments.

• Examples of simple Sparc instructions.
  • add (Paul p. 358)
  • sub (Paul p. 361)
  • and (Paul p. 366)
  • or (Paul p. 367)

• Parameter passing in registers (call by value):
  • The calling program puts the values in %o0, %o1, ... in order.
  • The called function accesses these same values in %i0, %i1, ...
  This is what is meant by overlapping register windows.

• If you haven't already done so, download the simple example simplesparc.m and compile by making Makefile.

• Parameter passing in the programs from laboratory 1:
  • Passing a simple value (passvalue):
    • C calling program
    • Sparc function
  • Call by reference (passaddr):
    • C calling program
    • Sparc function
  • Returning a value (returnvalue):
    • C calling program
    • Sparc function