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From: Sergey Fedorov <serge.fdrv@gmail.com>
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Date: Thu, 24 Mar 2016 18:52:03 +0300
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Subject: Re: [Qemu-devel] [PATCH 8/8] tcg: Clean up tb_jmp_unlink()
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To: =?UTF-8?Q?Alex_Benn=c3=a9e?= <alex.bennee@linaro.org>, sergey.fedorov@linaro.org
Cc: Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <rth@twiddle.net>, qemu-devel@nongnu.org, Peter Crosthwaite <crosthwaite.peter@gmail.com>

On 24/03/16 18:42, Sergey Fedorov wrote:
> On 24/03/16 18:36, Alex Bennée wrote:
>>> diff --git a/translate-all.c b/translate-all.c
>>>> index 8b4bfa713bf7..56c77a72773d 100644
>>>> --- a/translate-all.c
>>>> +++ b/translate-all.c
>>>> @@ -962,25 +962,21 @@ static inline void tb_reset_jump(TranslationBlock *tb, int n)
>>>>  /* remove any jumps to the TB */
>>>>  static inline void tb_jmp_unlink(TranslationBlock *tb)
>>>>  {
>>>> -    uintptr_t tb1, tb2;
>>>> +    TranslationBlock *tb1;
>>>> +    uintptr_t *ptb;
>>>>      unsigned int n1;
>>>>
>>>> -    tb1 = tb->jmp_list_first;
>>>> +    ptb = &tb->jmp_list_first;
>>>>      for (;;) {
>>>> -        TranslationBlock *tmp_tb;
>>>> -        n1 = tb1 & 3;
>>>> +        n1 = *ptb & 3;
>>>> +        tb1 = (TranslationBlock *)(*ptb & ~3);
>> I would hope the compiler saw through the duplicate indirect accesses
>> but maybe:
>>
>>     uintptr_t *ptb, ntb;
>>
>> and
>>
>>     ntb = *ptb;
>>     n1 = ntb & 3;
>>     tb1 = (TranslationBlock *)(ntb & ~3);
>>
>> would be clearer?
>>
> Why not? :) Will do this.

I'll do the same in tb_remove_from_jmp_list(). It will go to the patch 8
"tcg: Use uintptr_t type for jmp_list_{next|first} fields of TB".

-Sergey