.sect .text

! this is not a subroutine, but just a
! piece of code that computes the jump-
! address and jumps to it.
! traps if resulting address is zero
!
! Stack: ( value tableaddr -- )

.define .csb
.csb:
	lwz r3, 0(sp)
	lwz r4, 4(sp)
	addi sp, sp, 8

	lwz r5, 0(r3)            ! load default
	mtspr ctr, r5

	lwz r6, 4(r3)            ! fetch count

1:
	or. r6, r6, r6           ! test count
	beqctr                   ! exit if zero
	addi r6, r6, -1          ! otherwise decrement

	lwzu r7, 8(r3)           ! fetch target index, increment pointer
	cmpw r4, r7              ! compare with value
	bne 1b                   ! if not equal, go again

	lwz r7, 4(r3)            ! fetch target address
	mtspr ctr, r7

	or. r7, r7, r7           ! test it
	bnectr                   ! jump to target if non-zero
	b .trap_ecase            ! otherwise trap