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Date: Fri, 16 Aug 2013 10:35:15 +0200
From: Aurelien Jarno <aurelien@aurel32.net>
Message-ID: <20130816083515.GA4795@ohm.aurel32.net>
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Subject: Re: [Qemu-devel] [PATCH for-next 6/8] tcg-i386: Use new
 return-argument ld/st helpers
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To: Richard Henderson <rth@twiddle.net>
Cc: qemu-devel@nongnu.org

On Thu, Aug 15, 2013 at 01:44:08PM -0700, Richard Henderson wrote:
> On 08/15/2013 08:54 AM, Aurelien Jarno wrote:
> >> >  #  define GETRA() ((uintptr_t)__builtin_return_address(0))
> >> > -#  define GETPC_LDST() ((uintptr_t)(GETRA() + 7 + \
> >> > -                                    *(int32_t *)((void *)GETRA() + 3) - 1))
> >> > +/* The return address argument for ldst is passed directly.  */
> >> > +#  define GETPC_LDST()  (abort(), 0)
> > Why an abort here, while in the arm version, you adds support for
> > not defining GETPC_LDST?
> > 
> 
> GETPC_LDST is for the original helpers, when called from TCG.
> 
> In the arm case, TCG still uses the original helpers, so GETPC_LDST is used.
> 
> In the i386, TCG never uses the original helpers, so GETPC_LDST should never be
> used.  We could do like arm and completely drop the check, I suppose.

Ok, I haven't looked in details at the arm patches (i am currently
trying them), and I haven't really seen the difference. Then just ignore
this comment.

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net