Direct bit I/O

I have a bit-addressable var (ibase) that I am loading with a value and then rotating--placing the msb on an I/O pin (SData). The SData pin never changes--it stays high. What am I doing wrong? Thanks!

for(i=0;i<8;i++)
{ SClock = 0;
SData = ibase^7;
ibase = _irol_(ibase,1);
delay();
SClock = 1;
timer0_delay(5);
}