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Re: [Qemu-devel] [PATCH 11/15] tcg: split cpu_set_mxcsr()/cpu_set_fpuc()
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH 11/15] tcg: split cpu_set_mxcsr()/cpu_set_fpuc() |
Date: |
Thu, 22 Jun 2017 04:42:45 -0400 (EDT) |
----- Original Message -----
> From: "Zhong Yang" <address@hidden>
> To: "Paolo Bonzini" <address@hidden>
> Cc: address@hidden, "anthony xu" <address@hidden>, "a rigo" <address@hidden>,
> "Richard
> Henderson" <address@hidden>, "Thomas Huth" <address@hidden>
> Sent: Thursday, June 22, 2017 10:03:25 AM
> Subject: Re: [PATCH 11/15] tcg: split cpu_set_mxcsr()/cpu_set_fpuc()
>
> On Wed, Jun 21, 2017 at 03:15:25PM +0200, Paolo Bonzini wrote:
> >
> >
> > On 21/06/2017 12:19, Yang Zhong wrote:
> > > Split the cpu_set_mxcsr()/cpu_set_fpuc() with specific tcg code.
> > > tcg_update_mxcsr()/tcg_set_fpuc() need be implemented in tcg-stub.c
> > > file if tcg is disabled.
> > >
> > > Signed-off-by: Yang Zhong <address@hidden>
> > > ---
> > > accel/stubs/tcg-stub.c | 8 ++++++++
> > > target/i386/cpu.h | 15 +++++++++++++--
> > > target/i386/fpu_helper.c | 8 +++-----
> > > 3 files changed, 24 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/accel/stubs/tcg-stub.c b/accel/stubs/tcg-stub.c
> > > index dafb1d0..91625a8 100644
> > > --- a/accel/stubs/tcg-stub.c
> > > +++ b/accel/stubs/tcg-stub.c
> > > @@ -75,6 +75,14 @@ void dump_opcount_info(FILE *f, fprintf_function
> > > cpu_fprintf)
> > > {
> > > }
> > >
> > > +void tcg_update_mxcsr(CPUX86State *env)
> > > +{
> > > +}
> > > +
> > > +void tcg_set_fpuc(CPUX86State *env)
> > > +{
> > > +}
> > > +
> > > void cpu_loop_exit(CPUState *cpu)
> > > {
> > > abort();
> > > diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> > > index 8b3b535..229b216 100644
> > > --- a/target/i386/cpu.h
> > > +++ b/target/i386/cpu.h
> > > @@ -1643,8 +1643,19 @@ static inline int32_t x86_get_a20_mask(CPUX86State
> > > *env)
> > > }
> > >
> > > /* fpu_helper.c */
> > > -void cpu_set_mxcsr(CPUX86State *env, uint32_t val);
> > > -void cpu_set_fpuc(CPUX86State *env, uint16_t val);
> > > +void tcg_update_mxcsr(CPUX86State *env);
> > > +void tcg_set_fpuc(CPUX86State *env);
> > > +static inline void cpu_set_mxcsr(CPUX86State *env, uint32_t mxcsr)
> > > +{
> > > + env->mxcsr = mxcsr;
> > > + tcg_update_mxcsr(env);
> >
> > Instead of having to add stubs, please guard the call with "if
> > (tcg_enabled())". Same below.
> >
> > Paolo
> >
> Hello Paolo,
>
> Got it! thanks!
>
> From your comments + Richard Henderson's comments, i got below guideline
> (1) accel/stubs/tcg-stub.c
> This file is target-independent file, do not add x86-specific stubs
> functions into this file.
>
> (2) there are three kind of methods to mask TCG relative function
> a) if(tcg_enabled())
> b) if CONFIG_TCG
> c) stub function
>
> Paolo, which one is your prefer? a) ? please also make sure your prefer
> sequence, a) > b) > c) ?
There is also
d) method in AccelClass
It seldom makes sense, but when it does it's the best. Apart from this one,
a) > c) > b).
For target-independent code, "c" is more often the solution. For
target-dependent
code, "a" is more common.
Paolo
- Re: [Qemu-devel] [PATCH 03/15] tcg: tcg_handle_interrupt() function, (continued)
[Qemu-devel] [PATCH 06/15] kvmvapic: remove tcg related code, Yang Zhong, 2017/06/21
[Qemu-devel] [PATCH 08/15] tcg: make cpu_get_fp80()/cpu_set_fp80() static, Yang Zhong, 2017/06/21
[Qemu-devel] [PATCH 07/15] tcg: move cpu_sync_bndcs_hflags() function, Yang Zhong, 2017/06/21
[Qemu-devel] [PATCH 10/15] tcg: move tb related lock functions, Yang Zhong, 2017/06/21
[Qemu-devel] [PATCH 09/15] tcg: add the tcg-stub.c file into accel/stubs/, Yang Zhong, 2017/06/21
[Qemu-devel] [PATCH 11/15] tcg: split cpu_set_mxcsr()/cpu_set_fpuc(), Yang Zhong, 2017/06/21
Re: [Qemu-devel] [PATCH 11/15] tcg: split cpu_set_mxcsr()/cpu_set_fpuc(), Richard Henderson, 2017/06/21
[Qemu-devel] [PATCH 12/15] tcg: remove inline definition of flush_icache_range(), Yang Zhong, 2017/06/21
[Qemu-devel] [PATCH 13/15] tcg: disable tcg in CPUX86State struct, Yang Zhong, 2017/06/21
[Qemu-devel] [PATCH 15/15] tcg: add the CONFIG_TCG into Makefiles, Yang Zhong, 2017/06/21
[Qemu-devel] [PATCH 14/15] tcg: add the CONFIG_TCG for header, Yang Zhong, 2017/06/21
Re: [Qemu-devel] [PATCH 00/15] add disable-tcg option for x86 build, no-reply, 2017/06/21
Re: [Qemu-devel] [PATCH 00/15] add disable-tcg option for x86 build, Paolo Bonzini, 2017/06/21