i386/x86_64 segment register issuses (Re: PATCH: Fix x86 segment register access)

H. J. Lu hjl@lucon.org
Thu Mar 31 15:05:00 GMT 2005


On Thu, Mar 31, 2005 at 12:18:55AM +0200, Pau Aliagas wrote:
> On Wed, 30 Mar 2005, H. J. Lu wrote:
> 
> >On Wed, Mar 30, 2005 at 07:57:28AM -0800, Linus Torvalds wrote:
> 
> >>>There is no such an instruction of "movl %ds,(%eax)". The old assembler
> >>>accepts it and turns it into "movw %ds,(%eax)".
> >>
> >>I disagree. Violently. As does the old assembler, which does not turn
> >>"mov" into "movw" as you say. AT ALL.
> >
> >I should have made myself clear. By "movw %ds,(%eax)", I meant:
> >
> >	8c 18	movw   %ds,(%eax)
> >
> >That is what the assembler generates, and should have generated, for
> >"movw %ds,(%eax)" since Nov. 4, 2004.
> 
> Could this be the reason for the reported slowdown in the last six months?
> 

Can you elaborate?


H.J.



More information about the Binutils mailing list