[boost] Re: shared_ptr on ppc?

From: Alexander Terekhov (terekhov_at_[hidden])
Date: 2005-04-06 11:05:55

Alexander Terekhov wrote:
> 
> Peter Dimov wrote:
> [...]
> > we'll probably see a bigger hit on a dual PPC.
> 
> Try on it something along the lines of
> 
>   asm long atomic_decrement_weak( register long * pw ) {
> 
>       <load-UNreserved>
>       <add -1>
>       <branch if zero to acquire>
>       {lw}sync
> 
>     loop:
> 
>       <load-reserved>
>       <add -1>
>       <branch if zero to acquire>
>       <store-conditional>
>       <branch if failed to loop else to done>
> 
>     acquire:
> 
>       isync
> 
>     done:
> 
>       <...>
>   }

and 

 asm long atomic_decrement_strong( register long * pw ) {

      <load-reserved>
      <add -1>
      <branch if zero to acquire>
      {lw}sync

    loop:

      <store-conditional>
      <branch if !failed to done>
      <load-reserved>
      <add -1>
      <branch if !zero to loop>

    acquire:

      <store-conditional>
      <branch if failed to loop>
      isync

    done:

      <...>
  }

regards,
alexander.