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Re: [Qemu-devel] Re: Compile files only once: some planning
From: |
Blue Swirl |
Subject: |
Re: [Qemu-devel] Re: Compile files only once: some planning |
Date: |
Wed, 24 Mar 2010 20:00:28 +0200 |
On 3/24/10, Richard Henderson <address@hidden> wrote:
> On 03/24/2010 02:47 AM, Paolo Bonzini wrote:
>
> > 1) make CPUState define only common fields. Include CPUState at the
> > beginning of each per-target CPUXYZState.
> >
>
> Irritatingly, the common fields contain quite big TLBs. And the
> offsets from the start of env affect the compactness of the code
> generated from TCG. We really really want the general registers
> to come first to make sure that those offsets fit the host's
> reg+offset addressing mode.
One trick is to define a fixed offset (about half CPUState size) and
make env point to CPUState + offset. Then the negative part of the
offset space can be used efficiently. But this just doubles the space
that can be accessed fast, so it's not a big win.
- Re: [Qemu-devel] Re: Compile files only once: some planning, (continued)
- Re: [Qemu-devel] Re: Compile files only once: some planning,
Blue Swirl <=
[Qemu-devel] Re: Compile files only once: some planning, Michael S. Tsirkin, 2010/03/24
Re: [Qemu-devel] Re: Compile files only once: some planning, Paul Brook, 2010/03/24
Re: [Qemu-devel] Re: Compile files only once: some planning, Anthony Liguori, 2010/03/24