On Wed, 25 Jun 1997 llewins@ccgate.hac.com wrote:
> Date: Wed, 25 Jun 97 14:38:20 PST8
> From: llewins@ccgate.hac.com
> To: mpi-core@mcs.anl.gov
> Subject: Definition of "Byte"
>
> I believe we are missing a definition for the term "byte" used various
> places throughout the document. This presumably should go in the
> "Semantic Terms" section. For simplicity, the definition should be
> the same as that used in the ANSI C standard, to quote:
>
> "Byte -- the unit of data storage large enough to hold any member of
> the basic character set of the execution environment. It shall be
> possible to express the address of each individual byte of an object
> uniquely. A byte is composed of a contiguous sequence of bits, the
> number of which is implementation defined..."
>
> Without this definition, a implementor may interpret byte to mean an
> 8-bit quantity. This would render the following code non-portable:
>
> size_t size;
> char *buf;
>
> MPI_Pack_size (1, MPI_INT, MPI_COMM_WORLD, &size);
> buf = (char *)malloc(size);
>
> Lloyd Lewins
> Hughes Aircraft Co.
> llewins@ccgate.hac.com
>
> P.S. I note this since on my current machine (a dsp) "bytes" are 32
> quantities, and sizeof(char) == sizeof(short) == sizeof(int) ==
> sizeof(long) == sizeof(float) == sizeof(double) == 1!!
>
>
A. Skjellum, PhD, Assoc. Prof. of Computer Science; Mississippi State University
http://www.cs.msstate.edu/~tony; tony@cs.msstate.edu; 601-325-8435 (FAX -8997)
"You are in a maze of twisty little passages, all alike." Support MPI & MPI/RT!