[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [4351] Make the paged properties of the tb-jmp-cache ha
From: |
Edgar E. Iglesias |
Subject: |
Re: [Qemu-devel] [4351] Make the paged properties of the tb-jmp-cache hash function work for TARGET_PAGE_BITS ! = 12. |
Date: |
Tue, 6 May 2008 16:03:10 +0200 |
User-agent: |
Mutt/1.5.16 (2007-06-09) |
On Tue, May 06, 2008 at 01:31:02PM +0100, Paul Brook wrote:
> > {
> > target_ulong tmp;
> > tmp = pc ^ (pc >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS));
> > - return (tmp >> TB_JMP_PAGE_BITS) & TB_JMP_PAGE_MASK;
> > + return (tmp >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS)) &
> > TB_JMP_PAGE_MASK; }
>
>
> I'm not sure what you're trying to achieve here, but this is definitely wrong.
> TARGET_PAGE_BITS may be less than TB_JMP_PAGE_BITS.
Hi Paul,
Thanks for the comment.
I didn't find any page bits under 10 in the tree. Please note that the constant
beeing used is not TB_JMP_CACHE_BITS but TB_JMP_PAGE_BITS. Also that same right
shift constant was already used in the initial shift of pc in that same routine.
Before committing I ran tests with target page bits 10, 11, 12, and 13 and the
modified hash function behaved ok here. Are there more setups I should test ?
Best regards
--
Edgar E. Iglesias
Axis Communications AB