I imagine that there are lots of cases like this where a reduction or message passing is required but is not a reduce_add. I wonder if there is a more general way to do message passing / reduction with ISPC. I imagine we'll find out in future lectures.

Quotes from lecture and the ISPC documentation that helped me understand the uniform keyword: "Even though this function is run by [number] different program instances, there only needs to be one of this variable"

"A variable that is declared with the uniform qualifier represents a single value that is shared across the entire gang. (In contrast, the default variability qualifier for variables in ispc, varying, represents a variable that has a distinct storage location for each program instance in the gang.)"