From: Jiri Slaby <jirislaby@gmail.com>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Make shr to divide by power of 2 (resend)
Date: Sat, 15 Aug 2009 15:48:06 +0200 [thread overview]
Message-ID: <4A86BC96.9040702@gmail.com> (raw)
In-Reply-To: <20090815134312.GA7533@localdomain.by>
On 08/15/2009 03:43 PM, Sergey Senozhatsky wrote:
> Make an arithmetic right shift to divide by power of 2.
Why? Is out there a compiler not doing that?
Seems like it should be rather converted to DIV_ROUND_UP.
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> ---
> diff --git a/drivers/video/console/bitblit.c b/drivers/video/console/bitblit.c
> index 69864b1..b816151 100644
> --- a/drivers/video/console/bitblit.c
> +++ b/drivers/video/console/bitblit.c
> @@ -144,7 +144,7 @@ static void bit_putcs(struct vc_data *vc, struct fb_info *info,
> int fg, int bg)
> {
> struct fb_image image;
> - u32 width = (vc->vc_font.width + 7)/8;
> + u32 width = (vc->vc_font.width + 7) >> 3;
> u32 cellsize = width * vc->vc_font.height;
> u32 maxcnt = info->pixmap.size/cellsize;
> u32 scan_align = info->pixmap.scan_align - 1;
next prev parent reply other threads:[~2009-08-15 13:48 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-15 13:43 [PATCH] Make shr to divide by power of 2 (resend) Sergey Senozhatsky
2009-08-15 13:48 ` Jiri Slaby [this message]
2009-08-15 13:49 ` Robert P. J. Day
2009-08-15 14:12 ` Sergey Senozhatsky
2009-08-15 20:42 ` Jiri Slaby
2009-08-16 9:14 ` Sergey Senozhatsky
2009-08-17 7:15 ` Jiri Slaby
2009-08-17 7:31 ` Sergey Senozhatsky
2009-08-17 7:48 ` [PATCH 1/1] VIDEO: console, use DIV_ROUND_UP Jiri Slaby
2009-08-17 8:00 ` Sergey Senozhatsky
2009-08-17 8:00 ` Jiri Slaby
2009-08-17 8:08 ` Sergey Senozhatsky
2009-08-17 8:11 ` Jiri Slaby
2009-08-15 14:26 ` [PATCH] Make shr to divide by power of 2 (resend) Sergey Senozhatsky
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