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openpic: IRQ_check: search the queue a word at a time

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Search the queue more efficiently by first looking for a non-zero word,
and then using the common bit-searching function to find the bit within
the word.  It would be even nicer if bitops_ffsl() could be hooked up
to the compiler intrinsic so that bit-searching instructions could be
used, but that's another matter.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Scott Wood 2013-01-03 13:25:38 +00:00 committed by Alexander Graf
parent 6c5e84c25f
commit 4417c73305
1 changed files with 16 additions and 12 deletions
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28
hw/openpic.c
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@ -277,21 +277,25 @@ static inline int IRQ_testbit(IRQQueue *q, int n_IRQ)
static void IRQ_check(OpenPICState *opp, IRQQueue *q)
{
int next, i;
int priority;
int irq = -1;
int next = -1;
int priority = -1;
next = -1;
priority = -1;
for (i = 0; i < opp->max_irq; i++) {
if (IRQ_testbit(q, i)) {
DPRINTF("IRQ_check: irq %d set ivpr_pr=%d pr=%d\n",
i, IVPR_PRIORITY(opp->src[i].ivpr), priority);
if (IVPR_PRIORITY(opp->src[i].ivpr) > priority) {
next = i;
priority = IVPR_PRIORITY(opp->src[i].ivpr);
}
for (;;) {
irq = find_next_bit(q->queue, opp->max_irq, irq + 1);
if (irq == opp->max_irq) {
break;
}
DPRINTF("IRQ_check: irq %d set ivpr_pr=%d pr=%d\n",
irq, IVPR_PRIORITY(opp->src[irq].ivpr), priority);
if (IVPR_PRIORITY(opp->src[irq].ivpr) > priority) {
next = irq;
priority = IVPR_PRIORITY(opp->src[irq].ivpr);
}
}
q->next = next;
q->priority = priority;
}