lkml.org 
[lkml]   [2004]   [Feb]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: kernel/microcode.c error from new 64bit code


On Sat, 21 Feb 2004, Pavel Machek wrote:
>
> > + wrmsr(MSR_IA32_UCODE_WRITE,
> > + (unsigned long) uci->mc->bits,
> > + (unsigned long) uci->mc->bits >> 16 >> 16);
> ~~~~~~~~~~~~
>
> I see what you are doing, but this is evil. At least comment /* ">> 32"
> is undefined on i386 */ ?

Sorry, but you're wrong.

">> 32" is underfined PERIOD! It has nothing to do with x86, it's a C
standards issue. It's undefined on any 32-bit architecture. (shifting by
the wordsize or bigger is simply not a defined C operation).

The above is not evil. The above is the standard way of doing this in C if
you know the word-size is 32-bits or bigger.

Linus
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2009-11-18 23:46    [W:0.095 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site