From: Richard Henderson <rth@twiddle.net>
To: Paolo Bonzini <pbonzini@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
qemu-devel@nongnu.org
Cc: Peter Maydell <peter.maydell@linaro.org>,
Markus Armbruster <armbru@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 5/7] omap_intc: convert ffs(3) to ctz32() in omap_inth_sir_update()
Date: Mon, 30 Mar 2015 08:44:36 -0700 [thread overview]
Message-ID: <55196F64.6050409@twiddle.net> (raw)
In-Reply-To: <5508410B.8030003@redhat.com>
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~
next prev parent reply other threads:[~2015-03-30 15:44 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-17 11:56 [Qemu-devel] [PATCH 0/7] Convert ffs(3) to ctz32() Stefan Hajnoczi
2015-03-17 11:56 ` [Qemu-devel] [PATCH 1/7] bt-sdp: fix broken uuids power-of-2 calculation Stefan Hajnoczi
2015-03-17 14:37 ` Eric Blake
2015-03-17 11:56 ` [Qemu-devel] [PATCH 2/7] Convert (ffs(val) - 1) to ctz32(val) Stefan Hajnoczi
2015-03-17 12:09 ` Peter Maydell
2015-03-17 14:54 ` Stefan Hajnoczi
2015-03-17 11:56 ` [Qemu-devel] [PATCH 3/7] Convert ffs() != 0 callers to ctz32() Stefan Hajnoczi
2015-03-30 15:42 ` Richard Henderson
2015-03-17 11:56 ` [Qemu-devel] [PATCH 4/7] sd: convert sd_normal_command() ffs(3) call " Stefan Hajnoczi
2015-03-17 11:56 ` [Qemu-devel] [PATCH 5/7] omap_intc: convert ffs(3) to ctz32() in omap_inth_sir_update() Stefan Hajnoczi
2015-03-17 14:58 ` Paolo Bonzini
2015-03-30 15:44 ` Richard Henderson [this message]
2015-03-17 11:56 ` [Qemu-devel] [PATCH 6/7] os-win32: drop ffs(3) prototype Stefan Hajnoczi
2015-03-17 11:56 ` [Qemu-devel] [PATCH 7/7] checkpatch: complain about ffs(3) calls Stefan Hajnoczi
2015-03-17 12:02 ` [Qemu-devel] [PATCH 0/7] Convert ffs(3) to ctz32() Stefan Hajnoczi
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