SPMD is a higher level abstraction where the same program or set of instructions are divided into different instances. SIMD is a lower-level construct, where the processor design (capable of handling multiple data)helps the processors to attend to multiple inputs at once.
anonymous
SPMD is the result of a programmer's perspective while SIMD is the output of hardware's perspective.
l8b
This slide helped me understand ISPC a lot better; the programmer can think about it as a number of instruction streams all running at the same time with different values, but should also understand that in reality, it's a single instruction across lots of data, handled by the ISPC compiler.
zale
As always, this abstraction is a little leaky: it is important for the programmer to realize that the implementation is a SIMD program. Good lane utilization, for instance, is critical to the performance of an ISPC program, but that's not visible purely from the semantics of ISPC.
SPMD is a higher level abstraction where the same program or set of instructions are divided into different instances. SIMD is a lower-level construct, where the processor design (capable of handling multiple data)helps the processors to attend to multiple inputs at once.
SPMD is the result of a programmer's perspective while SIMD is the output of hardware's perspective.
This slide helped me understand ISPC a lot better; the programmer can think about it as a number of instruction streams all running at the same time with different values, but should also understand that in reality, it's a single instruction across lots of data, handled by the ISPC compiler.
As always, this abstraction is a little leaky: it is important for the programmer to realize that the implementation is a SIMD program. Good lane utilization, for instance, is critical to the performance of an ISPC program, but that's not visible purely from the semantics of ISPC.