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Subject: Re: [OMPI devel] amd64 atomic.h warnings
From: George Bosilca (bosilca_at_[hidden])
Date: 2010-06-07 21:54:42


On Jun 7, 2010, at 19:47 , Jeff Squyres wrote:

> I'm getting these warnings from PGI 7.0.7. Do they matter? Is "clobber" important?

clobber might be the most important piece of information there, it trigger a warning for the compiler that the condition code register have been altered.

This code is protected by OMPI_GCC_INLINE_ASSEMBLY, so if we're compiling it it means that somehow we detected that PGI support the GCC inline assembly. Now, if they only half-support it, there is not much we can do.

Can you send the assembly instructions generated by the PGI compiler for the following code:

   int32_t oldval;

   do {
      oldval = *addr;
   } while (0 == opal_atomic_cmpset_32(addr, oldval, oldval + delta));
   return (oldval + delta);

  Thanks,
    george.

>
> CXX mpicxx.lo
> "../../../opal/include/opal/sys/amd64/atomic.h", line 91: warning: "cc"
> clobber ignored
> : "memory", "cc");
> ^
>
> "../../../opal/include/opal/sys/amd64/atomic.h", line 83: warning: parameter
> "oldval" was set but never used
> int32_t oldval, int32_t newval)
> ^
>
> "../../../opal/include/opal/sys/amd64/atomic.h", line 112: warning: "cc"
> clobber ignored
> : "memory", "cc"
> ^
>
> "../../../opal/include/opal/sys/amd64/atomic.h", line 104: warning: parameter
> "oldval" was set but never used
> int64_t oldval, int64_t newval)
> ^
>
> --
> Jeff Squyres
> jsquyres_at_[hidden]
> For corporate legal information go to:
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>
>
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