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Re: [Qemu-devel] Re: [PATCH] Use ffs in favor of ffsll
From: |
Christoph Egger |
Subject: |
Re: [Qemu-devel] Re: [PATCH] Use ffs in favor of ffsll |
Date: |
Thu, 2 Jul 2009 10:39:08 +0200 |
User-agent: |
KMail/1.9.7 |
On Wednesday 01 July 2009 22:27:51 Blue Swirl wrote:
> On 7/1/09, Jan Kiszka <address@hidden> wrote:
> > Not all host platforms support the ll variant. This is not a critical
> > path, so go the easy way.
> >
> > - for (i = 0; i < ARRAY_SIZE(env->interrupt_bitmap); i++) {
> > - bit = ffsll(env->interrupt_bitmap[i]);
> > + for (i = 0; i < sizeof(env->interrupt_bitmap) / sizeof(int); i++) {
> > + bit = ffs(((int *)env->interrupt_bitmap)[i]);
> > if (bit) {
> > - pending_irq = i * 64 + bit - 1;
> > + pending_irq = i * 8 * sizeof(int) + bit - 1;
>
> I think this will not work on a big endian host.
A qemu_ffsll() implementation can be something like this:
int qemu_ffsll(long long mask)
{
int bit;
bit = ffs((int)mask);
if (bit == 0) {
mask >>= 32;
bit = ffs((int)mask);
if (bit) bit += 32;
}
return bit;
}
Christoph
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- [Qemu-devel] Re: [PATCH] Use ffs in favor of ffsll, (continued)
- [Qemu-devel] Re: [PATCH] Use ffs in favor of ffsll, Blue Swirl, 2009/07/01
- [Qemu-devel] Re: [PATCH] Use ffs in favor of ffsll, Jan Kiszka, 2009/07/01
- [Qemu-devel] [PATCH v2] Use ffs in favor of ffsll, Jan Kiszka, 2009/07/01
- Re: [Qemu-devel] [PATCH v2] Use ffs in favor of ffsll, Nathan Froyd, 2009/07/01
- [Qemu-devel] Re: [PATCH v2] Use ffs in favor of ffsll, Jan Kiszka, 2009/07/01
- Re: [Qemu-devel] [PATCH v2] Use ffs in favor of ffsll, Stuart Brady, 2009/07/01
- [Qemu-devel] [PATCH] Use ctz64 in favor of ffsll, Jan Kiszka, 2009/07/02
- [Qemu-devel] [PATCH v2] Use ctz64 in favor of ffsll, Jan Kiszka, 2009/07/02
- Re: [Qemu-devel] [PATCH v2] Use ctz64 in favor of ffsll, Paul Brook, 2009/07/03
- Re: [Qemu-devel] [PATCH v2] Use ctz64 in favor of ffsll, Jan Kiszka, 2009/07/04
Re: [Qemu-devel] Re: [PATCH] Use ffs in favor of ffsll,
Christoph Egger <=