timer.c: Optimize IRQ dispatch routines.

Remove dispatch_irq() and dispatch_cc_irqs().

For IRQs which handle exactly one timer interrupt, add new
dispatch_single_irq().  The mere fact that the IRQ has been called
suffices to prove that its interrupt enable bit (in TIMx_DIER) and
interrupt flag (in TIMx_SR) are set.  These facts are combined in
dispatch_single_irq(), which only needs to check if the timer_dev
handler is non-null before calling it and clearing the SR flag.

For IRQs which serve multiple timer interrupts, replace the
composition of calls to dispatch_irq() and dispatch_cc_irqs() with
individualized routines.  These eliminate unnecessary timer register
reads/writes, and, in the case of capture/compare interrupts, have a
loop unrolling performed.

0 files changed, 0 insertions, 0 deletions