Gathered loads forming DAG instead of trees in SLP vectorizer. When
doing the throttling analysis for such graphs, need to consider partially
matched gathered loads DAG nodes and consider extract and/or gather
operations and their costs.
The patch adds this analysis and allows cutting off the expensive
sub-graphs with gathered loads.
Reviewers: hiraditya, RKSimon
Pull Request: https://github.com/llvm/llvm-project/pull/177855
0666a777ec