Atomic::cmpxchg_ptr code duplication

[John Coomes]

Xiaobin Lu (Xiaobin.Lu at Sun.COM) wrote:
> On Mac OS X, I believe intptr_t is typedefed as "int" on both 32 & 64 
> bit. So, sizeof(intptr_t) on 64 bit Mac OS is still 4 and size(void*) is 8.

intptr_t has to be big enough to hold a void* (it's in the c99
standard).

I think there were c++ overloading problems on MacOS because 32-bit
intptr_t is unsigned long, instead of unsigned int as it is on Solaris
& Linux.  Even though they're the same size, overloading considers
them different types.

-John

> John Coomes wrote:
> > Paul Hohensee (Paul.Hohensee at Sun.COM) wrote:
> >   
> >> Sometimes compilers don't inline all the way through a call stack,
> >> i.e., they may have limits on inlining depth.  It's not a matter for
> >> the preprocessor, since we're talking methods, not macros.
> >>
> >> Assembly code template are things like gcc asm statements or
> >> .il functions.  Doesn't matter which.  What matters is whether the
> >> compiler actually inlines the asm code where you want it.
> >>     
> >
> > That's the kind of thing I was actually wondering about, along with
> > portability--consolidating them only works if sizeof(void*) ==
> > sizeof(intptr_t) on every platform.  They're the same on the platforms
> > SE supports, but maybe there are some oddball embedded platforms
> > around.
> >
> > -John
> >
> >   
> >> Christian Thalinger wrote:
> >>     
> >>> On Thu, 2009-04-02 at 09:54 -0400, Paul Hohensee wrote:
> >>>   
> >>>       
> >>>> If the platform-dependent versions are assembly code templates, then
> >>>> it's likely at some point that the C++ compiler(s) didn't inline
> >>>> properly
> >>>> using your suggested code.  I haven't looked in awhile, but I'm pretty
> >>>> sure there
> >>>> are some places that use your style of code and others that don't for
> >>>> because of that.
> >>>>     
> >>>>         
> >>> Hmm, not sure I understand.  AFAIK it makes no difference for inlining
> >>> in what header file the inline is defined, as long as both are included
> >>> and the compiler (preprocessor) finds it.  Or do you mean something
> >>> different by "assembly code templates", like .il files?
> >>>
> >>> -- Christian
> >>>
> >>>   
> >>>       
> >
> >   
>