Sparse matrices

[majosm]

WIP

cc @lukeolson

[majosm]

@inducer I started looking through the loopy codegen code to try to figure out how to generate temporaries for the reduction bounds to avoid islpy errors (as is done in the loopy example), but I'm having some trouble figuring out how best to do that. Seems like I need to create the temporaries inside InlinedExpressionGenMapper.map_reduce() before adding the reduction domain to the kernel, but I'm not sure how to make sure the temporaries get the right scope, dependencies, inames, etc. Any suggestions on how I could approach this? Should I maybe be doing it inside CodeGenMapper.map_index_lambda by collecting the reduction info ahead of time and creating temporaries before calling the exprgen_mapper?

[inducer]

Yes, working inside of CodeGenMapper.map_index_lambda seems like a possibly promising route. I'm not sur what info you would need to collect ahead of time though.