| Message ID | 1426593410-21405-6-git-send-email-stefanha@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 17/03/2015 12:56, Stefan Hajnoczi wrote: > + for (f = ctz32(level) + 1, i = f - 1, level >>= f - 1; > + f != 33; > + i += f, level >>= f) { > p = s->bank[j].priority[i]; > if (p <= p_intr) { > p_intr = p; > sir_intr = 32 * j + i; > } > - f = ffs(level >> 1); > + f = ctz32(level >> 1) + 1; > } Since it's 2.4, we might as well make the code nicer: while (level != 0) { i = ctz32(level); p = s->bank[j].priority[i]; if (p <= p_intr) { p_intr = p; sir_intr = 32 * j + i; } level &= level - 1; } Paolo
On 03/17/2015 07:58 AM, Paolo Bonzini wrote: > On 17/03/2015 12:56, Stefan Hajnoczi wrote: >> + for (f = ctz32(level) + 1, i = f - 1, level >>= f - 1; >> + f != 33; >> + i += f, level >>= f) { >> p = s->bank[j].priority[i]; >> if (p <= p_intr) { >> p_intr = p; >> sir_intr = 32 * j + i; >> } >> - f = ffs(level >> 1); >> + f = ctz32(level >> 1) + 1; >> } > > Since it's 2.4, we might as well make the code nicer: > > while (level != 0) { > i = ctz32(level); > p = s->bank[j].priority[i]; > if (p <= p_intr) { > p_intr = p; > sir_intr = 32 * j + i; > } > level &= level - 1; > } Agreed. r~
diff --git a/hw/intc/omap_intc.c b/hw/intc/omap_intc.c index ad3931c..0cf2d2d 100644 --- a/hw/intc/omap_intc.c +++ b/hw/intc/omap_intc.c @@ -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) { + for (f = ctz32(level) + 1, i = f - 1, level >>= f - 1; + f != 33; + i += f, level >>= f) { p = s->bank[j].priority[i]; if (p <= p_intr) { p_intr = p; sir_intr = 32 * j + i; } - f = ffs(level >> 1); + f = ctz32(level >> 1) + 1; } } s->sir_intr[is_fiq] = sir_intr;
The loop previously terminated on ffs(0) == 0, now it terminates on ctz32(0) + 1 == 33. Other than this change, ffs() is simply replaced with ctz32() + 1. Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- hw/intc/omap_intc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)