From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39729) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yn70w-0007VC-Nj for qemu-devel@nongnu.org; Tue, 28 Apr 2015 11:01:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yn70r-0001pA-2J for qemu-devel@nongnu.org; Tue, 28 Apr 2015 11:01:34 -0400 From: Kevin Wolf Date: Tue, 28 Apr 2015 16:59:51 +0200 Message-Id: <1430233258-31807-10-git-send-email-kwolf@redhat.com> In-Reply-To: <1430233258-31807-1-git-send-email-kwolf@redhat.com> References: <1430233258-31807-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 09/76] omap_intc: convert ffs(3) to ctz32() in omap_inth_sir_update() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Paolo Bonzini Rewrite the loop using level &= level - 1 to clear the least significant bit after each iteration. This simplifies the loop and makes it easy to replace ffs(3) with ctz32(). Cc: Peter Maydell Signed-off-by: Paolo Bonzini Signed-off-by: Stefan Hajnoczi Message-id: 1427124571-28598-8-git-send-email-stefanha@redhat.com Signed-off-by: Kevin Wolf --- hw/intc/omap_intc.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/hw/intc/omap_intc.c b/hw/intc/omap_intc.c index ad3931c..e9b38a3 100644 --- a/hw/intc/omap_intc.c +++ b/hw/intc/omap_intc.c @@ -60,7 +60,7 @@ struct omap_intr_handler_s { static void omap_inth_sir_update(struct omap_intr_handler_s *s, int is_fiq) { - int i, j, sir_intr, p_intr, p, f; + int i, j, sir_intr, p_intr, p; uint32_t level; sir_intr = 0; p_intr = 255; @@ -72,14 +72,15 @@ static void omap_inth_sir_update(struct omap_intr_handler_s *s, int is_fiq) for (j = 0; j < s->nbanks; ++j) { level = s->bank[j].irqs & ~s->bank[j].mask & (is_fiq ? s->bank[j].fiq : ~s->bank[j].fiq); - for (f = ffs(level), i = f - 1, level >>= f - 1; f; i += f, - level >>= f) { + + while (level != 0) { + i = ctz32(level); p = s->bank[j].priority[i]; if (p <= p_intr) { p_intr = p; sir_intr = 32 * j + i; } - f = ffs(level >> 1); + level &= level - 1; } } s->sir_intr[is_fiq] = sir_intr; -- 1.8.3.1