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Date: Wed, 04 Sep 2013 12:26:02 +0200
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Subject: Re: [Qemu-devel] [RFC qom-cpu 03/41] cpu: Turn
 cpu_get_tb_cpu_state() into a CPUClass hook
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To: =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= <afaerber@suse.de>
Cc: Peter Maydell <peter.maydell@linaro.org>, Jia Liu <proljc@gmail.com>, Anthony Green <green@moxielogic.com>, qemu-devel@nongnu.org, Alexander Graf <agraf@suse.de>, Blue Swirl <blauwirbel@gmail.com>, Max Filippov <jcmvbkbc@gmail.com>, Michael Walle <michael@walle.cc>, PowerPC <qemu-ppc@nongnu.org>, Paul Brook <paul@codesourcery.com>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Guan Xuetao <gxt@mprc.pku.edu.cn>, Aurelien Jarno <aurelien@aurel32.net>, Richard Henderson <rth@twiddle.net>

Il 04/09/2013 11:04, Andreas Färber ha scritto:
>  static inline TranslationBlock *tb_find_fast(CPUArchState *env)
>  {
> +    CPUState *cpu = ENV_GET_CPU(env);
> +    CPUClass *cc = CPU_GET_CLASS(cpu);
>      TranslationBlock *tb;
> -    target_ulong cs_base, pc;
> +    vaddr cs_base, pc;
>      int flags;
>  
>      /* we record a subset of the CPU state. It will
>         always be the same before a given translated block
>         is executed. */
> -    cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
> +    cc->get_tb_cpu_state(cpu, &pc, &cs_base, &flags);

I'm afraid you cannot turn inline functions into indirect calls like
this in hot paths.

One alternative would be to hoist the function call to the beginning of
cpu_exec, and ensure that any place that modifies the result calls
cpu_exit.  It may be a problem for SPARC's npc stuff, for which I have
no idea how it works.

Another is to change cpu-exec.c into a file that is #included by
target-*/helper.c or something like that.  This way cpu-exec.c can still
use the inline functions.

Paolo