Conditional Return

The ’C5x supports conditional returns (RETC) to avoid conditionally branching

around the return. Example 4–1 shows an overflow-handling subroutine

called if the main algorithm causes an overflow condition. During the subrou-tine,

the ACC is checked and, if it is positive, the subroutine returns to the call-ing

sequence. If it is not positive, additional processing is necessary before the

return. Note that RETC, like RET, is a 1-word instruction. However, because

of the potential PC discontinuity, RETC operates with the same effective

execution time as BCND and CC.