[petsc-dev] MPI_UNSIGNED_LONG_LONG in mpiuni.h

[Jed Brown]

Chetan Jhurani <chetan.jhurani at gmail.com> writes:

> Info about long long:
>
> Visual Studio 2005 supports long long (sizeof = 8)
> even when compiling in 32 bit mode, so I assume all
> later ones do.
>
> Trilinos 11.0+ uses long long for 64-bit indices.  I have tested
> it with two compilers (2005/2012) and I'm guessing others
> have used other versions.

We use 'long long' or '__int64', but I don't have any data about whether
the '__int64' option is still needed.  It sounds like maybe not.
Trilinos is C++ where as PETSc needs only a C compiler, and what is
"portable enough" for them does not necessarily carry over.

> About stdint.h:
>
> I see that it is there with Visual Studio 2012 on
> my machine, but not with 2005.  Below is more info
> on stdint and MS VS.  I never had a need to use
> it so can't say more than this.
>
> http://stackoverflow.com/questions/126279/c99-stdint-h-header-and-ms-visual-studio

Yeah, we've had this discussion before.