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From: Richard Henderson <rth@twiddle.net>
To: 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 3/7] Convert ffs() != 0 callers to ctz32()
Date: Mon, 30 Mar 2015 08:42:28 -0700	[thread overview]
Message-ID: <55196EE4.6010502@twiddle.net> (raw)
In-Reply-To: <1426593410-21405-4-git-send-email-stefanha@redhat.com>

On 03/17/2015 04:56 AM, Stefan Hajnoczi wrote:
> @@ -1989,8 +1989,7 @@ static void omap_mpuio_write(void *opaque, hwaddr addr,
>      case 0x04:	/* OUTPUT_REG */
>          diff = (s->outputs ^ value) & ~s->dir;
>          s->outputs = value;
> -        while ((ln = ffs(diff))) {
> -            ln --;
> +        while ((ln = ctz32(diff)) != 32) {
>              if (s->handler[ln])
>                  qemu_set_irq(s->handler[ln], (value >> ln) & 1);
>              diff &= ~(1 << ln);

Surely

	while (diff != 0) {
	    ln = ctz32(diff);
	    ...
	}

would be a better conversion.


r~

  reply	other threads:[~2015-03-30 15:42 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 [this message]
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
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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