[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH for-next 6/8] tcg-i386: Use new return-argument
From: |
Aurelien Jarno |
Subject: |
Re: [Qemu-devel] [PATCH for-next 6/8] tcg-i386: Use new return-argument ld/st helpers |
Date: |
Fri, 16 Aug 2013 10:35:15 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
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
address@hidden http://www.aurel32.net
- Re: [Qemu-devel] [PATCH for-next 4/8] tcg: Add mmu helpers that take a return address argument, (continued)
[Qemu-devel] [PATCH for-next 2/8] tcg-i386: Try pc-relative lea for constant formation, Richard Henderson, 2013/08/05
[Qemu-devel] [PATCH for-next 5/8] tcg: Tidy softmmu_template.h, Richard Henderson, 2013/08/05
[Qemu-devel] [PATCH for-next 6/8] tcg-i386: Use new return-argument ld/st helpers, Richard Henderson, 2013/08/05
[Qemu-devel] [PATCH for-next 7/8] tcg-arm: Use ldrd/strd for appropriate qemu_ld/st64, Richard Henderson, 2013/08/05
[Qemu-devel] [PATCH for-next 8/8] tcg-arm: Rearrange slow-path qemu_ld/st, Richard Henderson, 2013/08/05