From: Nicolas Pitre <nico@cam.org>
Date: Tue, 22 Jan 2008 14:21:56 GMT
Subject: Re: [PATCH] Use FIX_UTF8_MAC to enable conversion from UTF8-MAC to UTF8
Message-ID: <alpine.LFD.1.00.0801220917310.20753@xanadu.home>
In-Reply-To: <alpine.LFD.1.00.0801212025050.2957@woody.linux-foundation.org>

On Mon, 21 Jan 2008, Linus Torvalds wrote:

> First off, the common case is that the filename likely has everything in 
> plain 7-bit ascii. So rather than re-encoding by default, the first thing 
> to do is to just see if it even needs re-encoding. Even if it's as simple 
> as saying "does it have any high bits at all", that's going to be a *huge* 
> performance win.
> 
> So start off with something like
> 
> 	int is_usascii(const char *p)
> 	{
> 		char c;
> 
> 		do {
> 			c = *p++;
> 		} while (c > 0);
> 		return !c;
> 	}

You need to use "signed char" here.  On ARM a char is unsigned by 
default.  That's the case on some other systems too.


Nicolas