From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60462) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TquAh-0007wG-Ea for qemu-devel@nongnu.org; Thu, 03 Jan 2013 18:26:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TquAe-0001PT-2t for qemu-devel@nongnu.org; Thu, 03 Jan 2013 18:25:59 -0500 From: Scott Wood Date: Thu, 3 Jan 2013 17:25:38 -0600 Message-ID: <1357255540-28689-3-git-send-email-scottwood@freescale.com> In-Reply-To: <1357255540-28689-1-git-send-email-scottwood@freescale.com> References: <1357255540-28689-1-git-send-email-scottwood@freescale.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH v2 2/4] openpic: IRQ_check: search the queue a word at a time List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Scott Wood , qemu-ppc@nongnu.org, qemu-devel@nongnu.org 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 --- v2: use find_next_bit hw/openpic.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/hw/openpic.c b/hw/openpic.c index 66179c2..7645d67 100644 --- a/hw/openpic.c +++ b/hw/openpic.c @@ -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; } -- 1.7.9.5