AC for the T3D
William W. Carlson, Jesse M. Draper, Ida Supercomputing · 1995
We have modified the C language slightly to enable programmers to read and write remote memory efficiently with simple assignment statements. To create a programming model in which local data and remote data are differentiated solely by the ways in which they are declared, we have focused on pointers and arrays, the two C constructs which are most closely tied to addresses. The addition of a single keyword gives the programmer the ability to declare a pointer that can point to any memory location in the program’s virtual address space or to an array that is distributed among all the local memories of the program. By keeping software constructs to a minimum and enabling programmers to use underlying hardware efficiently, AC is solidly in the C tradition. Using the Free Software Foundation’s GNU C Compiler [Stal 94], we have implemented AC on the Cray T3D and have achieved excellent performance results compared to the Cray Standard C compiler.