[SYSTEMDS-1976] Slow codegen outer left/right mm w/ ultra-sparse inputs

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: SystemML 1.0.0
• Epic Link: Code generation for operator fusion
• Assignee: Matthias Boehm
• Reporter: Matthias Boehm
• Created: 28/Oct/17 04:50
• Updated: 22/Nov/17 23:24
• Resolved: 22/Nov/17 23:24

Description

Recent ALS-CG experiments with the ultra-sparse amazon reviews dataset (sparsity 1.2e-6) have show unnecessarily slow codegen outer (especially left mm) operations. This task aims to fix this by better cache blocking to ensure blocking itself does not introduce overhead for ultra-sparse matrices.